Managing Contaminated Animal and Plant Materials: Field Guide on ...

<strong>Managing</strong><strong>Contaminated</strong> <strong>Animal</strong><strong>and</strong> <strong>Plant</strong> <strong>Materials</strong><strong>Field</strong> <strong>Guide</strong> on Best Practices

Saqib Mukhtar, Ph.D., Associate Professor <strong>and</strong>Extension Agricultural Engineer, Texas AgriLifeExtension ServiceFrederick O. Boadu, Ph.D., J.D. (Law), Professor,Department of Agricultural Economics, Texas A&MUniversityYanhong H. Jin, Ph.D., Assistant Professor,Department of Agricultural Economics, Texas A&MUniversityAhmed Kalbasi, Ph.D., Research Associate,Department of Biological <strong>and</strong> AgriculturalEngineeringAuthorsBruce McCarl, Ph.D., Regents Professor,Department of Agricultural EconomicsWon-Bo Shim, Ph.D., Assistant Professor,Department of <strong>Plant</strong> Pathology <strong>and</strong> Microbiology,Texas AgriLife ResearchTom A. “Andy” Vestal, Ph.D., Professor <strong>and</strong>Extension Specialist, Texas AgriLife ExtensionService Organizational DevelopmentCody L. Wilson, Ph.D., National Center for Foreign<strong>Animal</strong> <strong>and</strong> Zoonotic Disease Defense <strong>and</strong> AdjunctAssociate Professor, Department of Environmental<strong>and</strong> Occupational Health, School of Rural PublicHealth, Texas A&M Health Science CenterDiane Bowen, Associate Editor <strong>and</strong> ExtensionCommunication Specialist, Texas AgriLifeExtension ServiceMelissa Smith, Assistant Graphic Designer <strong>and</strong>Extension Communication Specialist, TexasAgriLife Extension ServiceProductionCrystal Matern, Graduate Student Graphic Artist,Texas AgriLife Extension ServiceDouglas P. Starr, Ph.D., Professor of AgriculturalJournalism, Texas A&M University

Contents51377Introduction. Introduction, Purpose <strong>and</strong> Overview...........................................5. Decision Trees.............................................................................8General Considerations. <strong>Animal</strong> <strong>and</strong> <strong>Plant</strong> <strong>Materials</strong>.......................................................13. Planning.....................................................................................20. Procedures.................................................................................24. Safety <strong>and</strong> Biosecurity..............................................................36. Cost...........................................................................................74Best Practices <strong>and</strong> <strong>Guide</strong>lines for Specific Methods. Thermal.....................................................................................77. Burial.......................................................................................118. Composting.............................................................................159. Rendering................................................................................212. Alkaline Hydrolysis................................................................237. Digestion.................................................................................265. Emerging Methods..................................................................2983

Introduction<strong>Managing</strong> <strong>Contaminated</strong> <strong>Animal</strong> <strong>and</strong> <strong>Plant</strong><strong>Materials</strong>: <strong>Field</strong> <strong>Guide</strong> on Best Practicespresents the information required for the safe,effective, <strong>and</strong> economical disposal of contaminatedanimal <strong>and</strong> plant materials. Managementof these materials on a large scale (300 tons ofcarcasses or more) presents major challengesfor emergency personnel responding to diseases,natural <strong>and</strong> accidental incidents, or acts ofterrorism against enterprises engaged in foodproduction, processing, or distribution.Large-scale incidents typically involvelocal <strong>and</strong> state agencies, which have the authorityto make decisions about disposal. If thescale of the incident exceeds the ability of astate or local government to respond, the stateusually requests federal resources.PurposeThis book was designed to be used as areference for training <strong>and</strong> operations in preparing<strong>and</strong> disposing of contaminated animal <strong>and</strong>plant materials. It was produced by the TechnicalSupport Working Group, in conjunctionwith the U.S. Department of Agriculture <strong>and</strong>the Environmental Protection Agency, for l<strong>and</strong>owners,private industry, animal producers,<strong>and</strong> local, state, federal, <strong>and</strong> military governmentagencies.Responders should apply this informationin conjunction with their previous training <strong>and</strong>experience, site-specific regulatory <strong>and</strong> environmentalfactors, <strong>and</strong> st<strong>and</strong>ard procedures <strong>and</strong>policies already in place. Because every situationhas unique challenges, responders must beflexible enough to adjust to the situation ath<strong>and</strong> using the resources available to them.5

IntroductionThis field guide is intended to be a sourceof ideas <strong>and</strong> information on methods <strong>and</strong>technologies for the disposal of contaminatedanimals <strong>and</strong> plants <strong>and</strong> is not intended to beall-inclusive. The information given is foreducational <strong>and</strong> guidance purposes only.This guidance does not substitute for anystatute or regulation, nor is it a regulation itself.By its terms, the guidance itself does notimpose binding requirements on any Federalagency, States, other regulatory or resourcemanagement authorities or any other entity.Statutory provisions <strong>and</strong> regulations describedin this document may contain legally bindingrequirements that would apply to a particularsituation based on the circumstances.Reference to businesses, commercialproducts, or trade names is made with the underst<strong>and</strong>ingthat no discrimination is intended<strong>and</strong> no endorsement by the Technical Support<strong>Contaminated</strong> <strong>Animal</strong> DisposalWorking Group or any other U.S. Governmentagency is implied.Funding for this publication was providedby the National Center for Foreign <strong>Animal</strong><strong>and</strong> Zoonotic Disease Defense.OverviewSeven disposal options are discussedin this guide: thermal, burial, composting,rendering, alkaline hydrolysis, digestion,<strong>and</strong> emerging technologies. The “GeneralConsiderations” chapter pertains to all ofthese options. The disposal methods arediscussed in separate chapters, most ofwhich include six color-coded sections:Summary of the disposal method (purple),Regulatory synopsis (yellow), Planning(blue), Procedures (light blue), Safety (red),Biosecurity (light green), EnvironmentalImpacts (brown), <strong>and</strong> Cost (green).6

This format was designed to help practitioners<strong>and</strong> incident comm<strong>and</strong>ers compare thevarious disposal methods for evidence-based<strong>and</strong> consensus-based decision making. Decisiontrees to aid in choosing the appropriatedisposal method are included for contaminatedanimals (Fig. 1) <strong>and</strong> plants (Fig. 2). Atable listing methods considerations is alsoincluded in most chapters to further advancethe decision-making process.Incident comm<strong>and</strong> structure: Beforebeginning any disposal method, respondersmust obtain approval from the local, state, orfederal authorities providing leadership at theincident comm<strong>and</strong> post. The proper procedurefor a local/county incident comm<strong>and</strong> team tofollow when managing animal carcasses willcome from the incident comm<strong>and</strong>er <strong>and</strong> willdepend on the magnitude of the incident, thetype of agent, <strong>and</strong> the potential economic <strong>and</strong>environmental impact.7 7

Introduction<strong>Contaminated</strong> <strong>Animal</strong> DisposalFigure 1. Decision tree for contaminated animal disposal.An animalcarcassdisposalemergencyis declared.Site is nearresidential<strong>and</strong> publicareas, waterwells, busyroads, etc.(see setbackdistances*)Pathogen presentI. Prion/TSE (Examples: BSE, CWD, <strong>and</strong> scrapie)II. Spore-forming bacteria (Example: anthrax)III. Virus (Examples: avian influenza, foot-<strong>and</strong>mouthdisease, <strong>and</strong> rinderpest)YesNoSelect an offsite location(see site selection criteria*).Provide biosecure transportation.YesNoChoice PriorityRendering a 1FFI b 2ACB c 3TB g 4OWC h 5LF i, n 6MB j 7Outbreak site is nearresidential <strong>and</strong> public areas,water wells, busy roads, etc.(see setback distances*)Provide biosecure transportation if needed.Pathogen Type I Pathogen Type II Pathogen Type IIIChoice Priority Choice Priority Choice PriorityFFI b 1 Rendering a 1 IWC f 1FAH d 2 FFI b 2 TB g 2MAH e 3 ACB c 3 OWC h 3FAH d 4 LF i 4MAH e 5 Rendering a 5TB g 6 FFI b 6LF i 8 ACB c 7OAB l 9 OAB l 8The disposal site meets the selection criteria.*NoYesYesTransport to thestaging area.Choice PriorityRendering a 1FFI b 2ACB c 3TB g 4OWC h 5LF i, n 6MB j 7OAB m 10NoACBBSECWDFAHFFIIWCLFMAHMBOABOWCTBTSEYesSelect offsite location(see site selection criteria*)Provide biosecuretransportation.AbbreviationsAir-curtain burningBovine spongiform encephalopathyChronic wasting diseaseFixed alkaline hydrolysisFixed facility incinerationIn-house windrow compostingL<strong>and</strong>fillingMobile alkaline hydrolysisMass burialOpen-air burningOutdoor windrow compostingTrench burialTransmissible spongiform encephalopathyPathogen Type IChoice PriorityThen FFI b 1FAH d 2Pathogen Type IIChoice PriorityRendering a 1FFI b 2ACB c 3FAH d 4MAH e 5TB g 6LF i 7OAB l 8Pathogen Type IIIChoice PriorityRendering a 1FFI b 2ACB c 3FAH d 4TB g 5OWC h 6LF i 7OAB l 8(Continued on next page)8

Figure 1. (Continued).aNo storage is necessary for carcasses ≤ 200 tons (400cattle carcasses); otherwise, plan to store the extracarcasses. The throughput of a rendering plant is about100 tons/24 h.bNo storage is necessary for carcasses ≤ 12 tons (24cattle carcasses) <strong>and</strong> if the throughput of the fixedfacility incinerator is about 6 tons/24 h; otherwise, planto store the extra carcasses. Fixed facility incinerationof carcasses eliminates the consumption of water forthe disposal process.cNo storage is necessary for carcasses ≤ 200 tons (400cattle carcasses); otherwise, plan to store the extracarcasses. Throughput of an air-curtain burning systemis about 100 tons/24 h.dNo storage is necessary for prion-infected carcasses ≤15 tons <strong>and</strong> non-prion-infected carcasses ≤ 30 tons ifthe throughput of fixed alkaline hydrolysis is about 15tons/24 h <strong>and</strong> about 30 tons/24 h, respectively; otherwise,plan to store the extra carcasses. Water consumptionis a limiting factor in fixed alkaline hydrolysis <strong>and</strong>mobile alkaline hydrolysis (0.5–2 lb/1 lb of carcass).To dispose of the effluent of fixed alkaline hydrolysisin municipal waste treatment facilities (MWTF), it isnecessary to acidify <strong>and</strong> dilute it <strong>and</strong> obtain permissionfrom authorized personnel in the MWTF.eNo storage is necessary for prion-infected carcasses≤ 6 tons <strong>and</strong> non-prion-infected carcasses ≤ 12 tons ifthe throughput of mobile alkaline hydrolysis is about6 tons/24 h <strong>and</strong> about 12 tons/24 h, respectively; otherwise,store the extra carcasses. On-site use of mobilealkaline hydrolysis eliminates the biosecure transportationcosts but requires skilled drivers/operators.fNo transportation is necessary. No storage is necessaryfor carcasses ≤ 200 tons (about 200,000 chickens);otherwise, plan to store the extra carcasses. Thethroughput of in-house windrow composting dependson the size of the poultry house <strong>and</strong> availableequipment. For example, 10 skid-steers can make awindrow (12 ft wide <strong>and</strong> 6 ft tall) composting pile forabout 400 tons of carcasses within 2 days of operation.gNo storage is necessary for carcasses ≤ 800 tons (1,600cattle carcasses); otherwise, plan to store the extracarcasses. A trench digger with 1 yd 3 bucket capacitywill trench <strong>and</strong> bury about 800 tons of carcasses within2 days.(Continued on next page)99

Introduction<strong>Contaminated</strong> <strong>Plant</strong> DisposalFigure 1. (Continued).hNo storage is necessary for carcasses ≤ 200 tons (400cattle carcasses); otherwise, plan to store the extracarcasses. The throughput of windrow composting dependson the size of carcasses, preprocessing (carcassgrinding), <strong>and</strong> available equipment. For example, 10skid-steers can make a windrow (12 ft wide <strong>and</strong> 6 fttall) composting pile for about 400 tons of carcasseswithin 2 days of operation.iNo storage is necessary for carcasses ≤ 200 tons (400cattle carcasses); otherwise, plan to store the extra carcasses.The throughput of carcass l<strong>and</strong>filling dependson the size of the Type I (modern) l<strong>and</strong>fill, transportationvehicles <strong>and</strong> processing machinery. Most l<strong>and</strong>fillshave a capacity of less than 100 tons/day.jCarcass mass burial capacity depends on the availabilityof equipment, personnel, <strong>and</strong> the required pitdimensions.k, lThe capacities for carcass bin composting <strong>and</strong> digestionare limited; these methods are not appropriate fordisposal of a large quantity of dead animals.mCarcass open-air burning is the last choice for disposalof carcasses, <strong>and</strong> its capacity depends on the trenchlength.nL<strong>and</strong>filling costs:1. The charge can range from $10 to $50 per ton, notincluding costs for transporting the carcasses to thel<strong>and</strong>fill. Source: Nebraska Department of EnvironmentalQuality, 2004.2. The actual price of using a l<strong>and</strong>fill in Californiawas $42.55/ton for dead stock. (Source: Personalcommunications with Matthew Hickman, RiversideCounty Waste Management Department, MorenoValley, CA, August 21, 2006).*Carcass disposal site specifications <strong>and</strong> regulations forthermal destruction, burial, <strong>and</strong> composting methods:• Perform thermal destruction of large numbers of animalcarcasses (usually more than 1,000 cattle carcasses)at a distance of at least 2 miles (3 km) fromresidential buildings, roads, <strong>and</strong> utilities (wires/lines) <strong>and</strong> from any public, religious, historical, <strong>and</strong>archaeological areas for the air-curtain burning <strong>and</strong>open-air burning systems. If possible, consider leavingthe same distance from crop fields <strong>and</strong> wildlife.This will protect the public from smoke inhalation(Continued on next page)10

Figure 1. (Continued).<strong>and</strong> excessive heat <strong>and</strong> can prevent fire damage toproperty, plants, <strong>and</strong> wildlife.• Consult the USDA Natural Resources ConservationService <strong>and</strong> evaluate the site for water table <strong>and</strong>proper soil conditions.• Use refractory boxes for air-curtain burning systemswhere the site has a high water table (< 2 ftfrom the bottom of a planned trench) or rocky soil<strong>and</strong> where the construction of trenches is difficult<strong>and</strong> costly.• When choosing an appropriate site for carcassburial, consider sites that are a minimum of 150 ftfrom private wells, springs, watercourses, sinkholes,streams, springs (or any source of water usedfor domestic purposes), <strong>and</strong> public areas; 200 ftfrom residences or property lines; 500 ft from publicwells; 1,000 ft for the burial of disease-infectedcarcasses from public <strong>and</strong> private water-supplywells; <strong>and</strong> 1,325 ft from public roads, highways,<strong>and</strong> parks.• The composting site should be at least 3 ft abovethe high water table level <strong>and</strong> 300 ft from sensitivewater resources (such as streams, ponds <strong>and</strong> wells,etc.). It should have 1–3% slope to provide properdrainage <strong>and</strong> prevent ponding of water.11 11

Introduction<strong>Contaminated</strong> <strong>Plant</strong> DisposalFigure 2. Decision tree for contaminated plant disposal.A plant disposal emergency has been declared.Y = yesN = noAnnual field cropsCrops in large areaswith very limitedtransportation optionsPerennial field cropsCrops, including trees<strong>and</strong> lumber, with limitedtransportation optionsNursery greenhouse plantsTransportation optionsavailableHighly contagiouspathogen (APHIS 1Select Agent)?Environmental issues(such as air quality)?Crops dried <strong>and</strong>suitable for burning?<strong>Field</strong> burning <strong>Field</strong> burial Natural decomposition Open-air burning L<strong>and</strong>filling1USDA <strong>Animal</strong> <strong>and</strong> <strong>Plant</strong> Health Inspection Service, http://www.aphis.usda.gov12

General ConsiderationsMany management practices are availablefor the disposal of contaminated plants <strong>and</strong>animals. The “best” method depends on thecircumstances at h<strong>and</strong>. Factors that affect thechoice of disposal method include:• The nature of the incident or outbreak(such as species of animal <strong>and</strong> type ofpathogen)• Site characteristics• Amount of contaminated materials to beh<strong>and</strong>led• Local, State, <strong>and</strong> Federal regulatoryconstraints• Facilities availableWhen planning a response to an incidentor outbreak, practitioners <strong>and</strong> incident comm<strong>and</strong>teams also must consider:• Worker health <strong>and</strong> safety• Security• Transportation• Equipment• Environmental impacts• Public perception• Direct <strong>and</strong> indirect costsInformation about these factors can guidedecision makers in selecting the most appropriatedisposal method for a specific contaminatedmaterial, pathogen, <strong>and</strong> location.13

General Considerations14Disposal of contaminated plant materialsTo protect the U.S. agricultural industry, itis vital that plant pathogens (disease-causingorganisms) <strong>and</strong> contaminated plants be destroyedor disposed of effectively.A key difference between infectiouspathogens of plants <strong>and</strong> those of animals isthat plant pathogens rarely infect humans. Afew isolated cases of human infections havebeen found in immuno-compromised patients.If the appropriate protective gear <strong>and</strong> commonsense are used, human infection by plantpathogens is unlikely.The most practical <strong>and</strong> economically feasibletechniques for disposing of contaminatedplants are described in detail in the specificmethods sections in this guide:• Thermal destruction methods (fieldburning, open-air burning)• Burial methods (field burial, l<strong>and</strong>filling)• Evolving <strong>and</strong> alternative methods (notillagecropping system, crop rotation)To select the best disposal methods, usersneed to have a baseline underst<strong>and</strong>ing of:• The classifications of plant materials• <strong>Plant</strong> diseases <strong>and</strong> epidemiology• The general considerations for h<strong>and</strong>lingcontaminated plant materialsThis manual provides information on thebest practices <strong>and</strong> disposal methods for contaminatedplant materials. It is not intended to be aguide for general crop-disease management.In the United States, diverse groups ofplants are cultivated, imported, <strong>and</strong> processed.Table 1 categorizes these plants into three majorgroups: annual field crops, perennial fieldcrops, <strong>and</strong> nursery greenhouse plants. Thegroups are organized according to the disposalmethodologies outlined in this guide.

Table 1. Characteristics, disease-control considerations <strong>and</strong> disposal issues of plant groupscultivated, processed, <strong>and</strong>/or imported in the United States.Consideration Annual field crops Perennial field crops Nursery greenhouse plantsExamplesGeneralcharacteristicsDisease controlKey disposalissuesCotton, corn, soybeans,tomatoes, tobacco, wheat,<strong>and</strong> potatoes• <strong>Plant</strong>ed in large areas acrossthe U.S.• Generally produced in theU.S. <strong>and</strong> a significantportion exported• Not cost-effective to harvest<strong>and</strong> transport for disposalpurposes• Most pathogens that cancontaminate these cropshave already beenintroduced to the U.S.• Key disease controlstrategies include the use ofresistant hybrids <strong>and</strong> propercultural practices• Large area of production• Difficulty of harvesting <strong>and</strong>transporting infected crops• High epidemic potentialGrapes, citrus, pome fruits (apples,pears), stone fruits (almonds,peaches, plums), <strong>and</strong> lumber• Can be planted in large areas butnot at the scale of annual fieldcrops• Typically woody plants <strong>and</strong>relatively of larger size• Because of the plant size,transportation can be an issue• Prone to insect <strong>and</strong> virus damage• New pathogens from othercontinents can be introduced• Because of the crops’ higheconomic value, pesticides <strong>and</strong>fungicides are used to controldiseases• Larger crop size• Transportation difficulty• Disposal location (if burning orburial is planned)Geraniums, pansies, <strong>and</strong> otherseasonal plants in single- <strong>and</strong>multi-season greenhouses• High-value plants• Restricted production/distribution locations• Shipping-friendly• Significant portion importedfrom foreign countries• Vulnerable to new,introduced pathogens(particularly importedplants)• Strict quarantine measuresenforced• New pathogen introduction• Rapid diagnosis necessary• Disposal location1515

General Considerations16Disposal of contaminated animal materialsBefore disposal or treatment, animal carcassesmust be preprocessed <strong>and</strong> then movedfrom the disaster area to the disposal site.Carcass preprocessing involves the biosecureh<strong>and</strong>ling <strong>and</strong> disinfection of contaminatedanimal carcasses. This step includesnot only collecting the dead animals, but alsosometimes preparing them, such as grinding,packing, <strong>and</strong> sterilizing the carcasses <strong>and</strong> storingthem in enclosed containers.Carcass transportation is the movement ofthose dead bodies from a disaster area to thedisposal site.The objectives of preprocessing <strong>and</strong> transportationare to properly prepare <strong>and</strong> transportinfected animal carcasses to prevent:• The transmission of diseases to otheranimals or humans• The production of excessive odors• The contamination of soil, water, air,<strong>and</strong> plantsThe carcasses must be collected <strong>and</strong>h<strong>and</strong>led hygienically <strong>and</strong> without physicallydamaging them during transportation.To control the spread of infectious diseases,it is important that dying <strong>and</strong> deceasedanimals be collected <strong>and</strong> removed from livestock<strong>and</strong> poultry operations quickly. Delayingthe removal of carcasses to fixed-facilitysites (such as rendering, incineration, alkalinehydrolysis, <strong>and</strong> digestion plants) may causethe disease agents to be spread to the environmentor other animals.Components neededDuring a catastrophic animal event, carcasspreprocessing <strong>and</strong> transportation requireseveral main components:

• Approved disinfecting materials• Trained workers• Appropriate equipment for preprocessing• Vehicles for transportation• Fuel• ElectricityPacking <strong>and</strong> h<strong>and</strong>ling equipment that isdesigned to manage a specific type of animalcarcasses, such as cattle, may or may not beappropriate for dealing with a mass die-off ofother species, such as poultry.The loading <strong>and</strong> transportation requirementswill be affected by the physical conditionof the diseased animals or carcasses <strong>and</strong>the location of the selected disposal sites.Deteriorated or decomposed carcasses <strong>and</strong>some types of disease infections may call forcertain portable disposal equipment, such asa portable gasifier <strong>and</strong> mobile alkaline hydrolysisapparatus, or they may require on-sitedisposal methods, such as trench burial <strong>and</strong>outside windrow composting.Normally, dead animals are transportedover long distances for disposal only if theyare fresh carcasses with no signs of deterioration.Smaller infected carcasses are collected<strong>and</strong> transferred quickly to the assigned disposalsites in containers able to hold 25,000pounds. However, larger carcasses (cattle)must be reduced in size <strong>and</strong> stored in temperature-controlledvehicles on site until theycan be transported to a central processing ordisposal facility.Carcasses with disease-causing organismsrequire special vehicular containers thatare sealed <strong>and</strong> equipped with liquid collection<strong>and</strong>/or absorption systems. To reduce thespread of pathogenic microorganisms, thevehicles transporting animal carcasses mayrequire air-filtration systems.Cold storage of carcasses reduces odors,reduces chemical <strong>and</strong> microbial activities, extendsthe amount of time needed for disposal,1717

General Considerationsprevents scavenging, <strong>and</strong> keeps the carcassesout of sight.Some large poultry <strong>and</strong> swine producersfreeze farm-animal carcasses in portable coldstorageunits. Once filled, the units can behauled away to central disposal sites. However,this process has high installation <strong>and</strong> utilitycosts <strong>and</strong> requires defrosting if the subsequentprocessing includes size reduction.Carcass preprocessing provides raw materialsfor rendering, lactic acid fermentation,<strong>and</strong> biogas generation. It also minimizes therisk of transmitting disease during transportthrough populated or animal production areas.Figure 1 is a schematic of how the preprocessingmodel might work for infected animalcarcasses.Although the decontamination proceduresdescribed reduce the threat of disease transmission,keep in mind that animal catastrophicemergencies are rare, <strong>and</strong> workers withoutproper training <strong>and</strong> education may hesitate todisinfect the carcasses.18

Figure 1. A schematic flow of farm-animal carcasses in storage, preprocessing, <strong>and</strong>transportation. When dealing with a communicable disease such as bovine spongiform encephalitis,it may be necessary to process all the stored manure on the farm (Pullen, 2004, in NationalAgricultural Biosecurity Consortium for Carcass Disposal Working Group report, NationalAgricultural Biosecurity Center, Kansas State University).Example: Bovine spongiform encephalitis is discovered on a 60-cow dairyNormal: Store manure solids.Periodic transfer of solids to cropl<strong>and</strong>Disease outbreak:Transfer all manureTemporary holdingof organic feedstockFinal processingat central siteManureStorageMass depopulationOn-farm storageof normal mortalityOn-farm preprocessing (ground,liquefied, <strong>and</strong> sterilized)Mineralfertilizersfor areafarmsEnergyMinimalresidue1919

PlanningPlanning considerations<strong>Managing</strong> the disposal of a large number ofcontaminated animal carcasses requires a properplan to match the selected disposal method.Take these steps to ensure the safety <strong>and</strong> biosecurityof the workers, the general public, <strong>and</strong>the environment during the collection, storage,h<strong>and</strong>ling, <strong>and</strong> transportation stages:• Consult with Federal, State, county, <strong>and</strong>city officials to find the most appropriateroutes for transporting the dead animalsfrom the farm-animal operations to thecarcass disposal sites.• Consult with your State’s regulatoryagencies for the minimum setback distancesrequired to locate the temporarystorage <strong>and</strong> pickup areas of infected farmanimals. They must be placed far fromthe public, homes, healthy animals, <strong>and</strong>routinely traveled roads.General Considerations• Set up the entire system of carcass processing<strong>and</strong> transport under veterinarysupervision. This will help prevent <strong>and</strong>/orcontrol the spread of infectious diseases.• Follow this section’s biosecurity guidelinesfor cleaning <strong>and</strong> disinfecting allcontainers <strong>and</strong> vehicles before they leavethe affected premises <strong>and</strong> again after thematerials have been unloaded at the disposalsite.• Provide ample temporary storage for thecarcasses if they are located in a warmclimate, if equipment is inaccessible forh<strong>and</strong>ling <strong>and</strong> transportation, if controllingwild animals (such as coyotes or feral pigs)is impossible, if disease vectors (organismsthat transmit pathogens away from theirsource) exist, or if more preparation time isrequired for the disposal process.20

• To achieve suitable conditions for movingthe carcasses to a processing facility,consider picking up the carcasses daily<strong>and</strong> bringing short-term freezing unitsto the farm. Remember that neither ofthese options eliminates pathogenicmicroorganisms.• Keep records of skilled personnel (suchas contractors, operators, <strong>and</strong> drivers)who can provide mechanical h<strong>and</strong>ling,storage, <strong>and</strong> conveyance of infected animalcarcasses.• Brief <strong>and</strong> train the supervisors, equipmentoperators, <strong>and</strong> drivers about allpertinent environmental, transportation,<strong>and</strong> public health regulations.• Train the personnel on how to usepersonal protective equipment <strong>and</strong> tocollect <strong>and</strong> h<strong>and</strong>le diseased animals <strong>and</strong>carcasses in the various stages of preprocessing<strong>and</strong> transportation.• Train the workers across the multiple city,county, <strong>and</strong> State jurisdictions. Also educatethem about the regulations on publichealth, the displacement of carcasses, <strong>and</strong>the protection of the environment in thosejurisdictions.• Prevent work hazards by using OccupationalSafety <strong>and</strong> Health Administration(OSHA) st<strong>and</strong>ards for the people workingin carcass preprocessing <strong>and</strong> transportation.• Keep <strong>and</strong> update a transportation routeguide for moving large numbers of carcassesin an emergency.• Provide equipment <strong>and</strong> vehicles, includingcranes, heavy trucks, tractors, bulldozers,front-end loaders, shovels, <strong>and</strong> containers(such as roll-off or drop-off), to lift, move,load, <strong>and</strong> transport the carcasses. Table2 lists some of the contractors that collect,h<strong>and</strong>le, decontaminate, <strong>and</strong> transportcarcasses. Also, some poultry production2121

Planningunits, rendering plants, <strong>and</strong> l<strong>and</strong>fillingcompanies have transportation systemsthat can be used for hauling dead animalsto disposal sites. In Nebraska, contractorscan transport up to 1.2 millionpounds of carcasses a day from disasterareas to rendering plants.• Plan to use large off-road haulers inemergency situations if the travel routeGeneral Considerationsallows them. The greater capacity ofthese haulers reduces the number ofloads <strong>and</strong> trips.• Maintain <strong>and</strong> update a list of commercialdead-animal haulers. Agencies suchas the California Department of Food<strong>and</strong> Agriculture provide this informationon their Web sites.22

Table 2. Examples of contractors that collect, h<strong>and</strong>le, decontaminate, <strong>and</strong>/or transportcarcasses.Company Nature <strong>and</strong> throughput of the work Contact informationSubcontractors of Tetra Tech EM, Inc.*Sanitec ® Microwave Healthcare WasteDisinfection SystemContractors of Riverside CountyWaste Management (l<strong>and</strong>fillingcompany)Collection, h<strong>and</strong>ling, <strong>and</strong> transportationof up to 2,400 tons/dayDecontamination of more than 14 tons ofcarcasses/dayCarcass transportation <strong>and</strong> disposal of upto 80 tons/day8030 Flint StreetLenexa, KS 66214Phone: 913-894-26001250 24th St., NW Suite 350Washington, DC 20007Phone: 202-263-3630www.sanitecindustries.com14290 Frederick St.Moreno Valley, CA 92553Phone: 909-468-3308http://www.rivcowm.orgPhillips <strong>and</strong> Jordan, Inc. Transportation of up to 1,200 tons/day P.O. Drawer 604, 191 P&J Rd.Robbinsville, NC 28771Phone: 800-511-6027www.p<strong>and</strong>j.comThese are examples only <strong>and</strong> not an exhaustive list. Endorsement of companies, individuals, or their services mentioned is notintended, nor is criticism implied of similar companies, individuals, or services that are not mentioned.*Source: Telephone conversations with Edward Hubert <strong>and</strong> David A. Zimmermann, (Dave.Zimmermann@ttemi.com) of Tetra Tech,Sept. 18, 2006.2323

ProceduresGeneral ConsiderationsProcedures for collection <strong>and</strong> storageFollow these procedures for collecting<strong>and</strong> storing contaminated carcasses <strong>and</strong> othermaterials:• Secure the carcasses <strong>and</strong> other itemsawaiting preprocessing, transportation,<strong>and</strong> disposal to prevent unauthorizedaccess by people, access by scavengers,<strong>and</strong> potential disease spread to susceptiblespecies.• Use a closed building or cold-storagefacility as a first priority for collecting<strong>and</strong> storing farm carcasses. Also controlthe wastewater runoff from the coldstoragefacilities.• Because of the biosecurity aspects (seethe “Safety <strong>and</strong> Biosecurity” section ofthis chapter) of storing the weights ofinfected carcasses, keep records on thecarcasses entering <strong>and</strong> exiting the coldstorage facilities.• When possible, wrap the carcasses securelyin plastic <strong>and</strong> pack them in largecontainers, such as lined wooden crates,in a designated storage area.• If a catastrophic event occurs or ifadequate disposal facilities are unavailable,store the carcasses in a barn, shed,or other covered space to protect themfrom snow or rain. When the storagetemperatures are between 46 <strong>and</strong> 68 °F(8 <strong>and</strong> 20 °C), store the carcasses for nomore than 72 hours. The University ofMinnesota Extension Service recommendsthat they be stored for no morethan 7 days at storage temperatures ofless than 45 °F (7 °C). The Government24

of Ontario, Canada, recommends storingcarcasses up to 240 days after the animals’death if they are stored in a frozen(about 0 °F or -18 °C) state.• To minimize the amount of energy requiredfor refrigeration, transport the frozencarcasses in sealed, insulated trucks.• Use stationary air-conditioned unitswhenever the mobile units are notequipped with refrigeration systems <strong>and</strong>it takes more than 1 or 2 days to load thedead livestock into truck containers.• Before loading <strong>and</strong> after unloading,thoroughly clean the storage facilitiesinside <strong>and</strong> out to prevent contaminationwithin the facilities <strong>and</strong> in the surroundingareas. After cleaning, treat hard,nonporous surfaces of the facility withan EPA-registered disinfectant; be sureto follow all label precautions <strong>and</strong> directions.The choice of disinfectant dependson the material being decontaminated.• Select a dry, cool area downwind fromother agricultural <strong>and</strong> nonagriculturaloperations to set up the temporary storagefacility. Do not locate this facilitynear property lines or roads.• To store carcasses temporarily, use storagesystems such as preconstructed rolloffcontainers, dumpsters, <strong>and</strong>/or possiblysilage trenches. Figures 2 <strong>and</strong> 3 show thegeneral views of these storage systems.• Use earth-moving equipment to storethe carcasses in piles on or above theground surface.• Use impervious materials such as polyethyleneor compacted clay to preventseepage from piled carcasses fromentering the soil. Control water penetrationinto <strong>and</strong> runoff from outdoor pilesby building temporary dikes (Fig. 4).• Cover the carcass pile with soil to preventscavenging <strong>and</strong> disease transmissionduring temporary storage.2525

ProceduresGeneral ConsiderationsFigure 2. A dumpster (Left, courtesy of Teena Middleton, Ag ProVision Company, Kenansville,NC) that can be used for storage <strong>and</strong> a roll-off container (Courtesy of Kent Munden, USDA<strong>Animal</strong> <strong>and</strong> <strong>Plant</strong> Health Inspection Service (APHIS), Clifton, TX) that can be used for transportationof carcasses.26

Figure 3. Trench silage storage used to store carcasses temporarily(Courtesy of Teena Middleton, Ag ProVision Company, Kenansville, NC).Soil2 plasticfilm1 plasticfilmTires, planks, bales of haySoilPlastic cover sheetSoilEarthSilageEarthSlope1.5% 1.5%2727

ProceduresGeneral ConsiderationsFigure 4. Temporary storage (for 1 to 2 days) of poultry carcasses with a berm to controlwater runoff <strong>and</strong> run-on (Courtesy of Kent Munden, USDA-APHIS, Clifton, TX).28

H<strong>and</strong>lingWhen h<strong>and</strong>ling carcasses of diseasedanimals, use equipment such as trucks, bins,backhoes, tractors, <strong>and</strong> front-end loaders withdifferent bucket sizes (1 to 4 cubic yards) tolift, move, <strong>and</strong> load the carcasses <strong>and</strong> relatedmaterials.Use a tractor with a front-end loader toplace the livestock bodies in containers (Fig.5). For ease in loading, keep 7 feet of clearanceon all sides of each container.Consider the physical conditions of thediseased carcasses, <strong>and</strong> use the appropriateequipment so that they can be h<strong>and</strong>led <strong>and</strong>displaced carefully without destroying them.Use the h<strong>and</strong>ling equipment to carry onlythe carcasses <strong>and</strong> related co-disposal materials(such as soil in burial systems, trash in l<strong>and</strong>fillingsystems, <strong>and</strong> carbon sources in thermaldestruction <strong>and</strong> composting systems) to thedisposal site or when unloading the finishedwaste materials. Do not use the h<strong>and</strong>lingequipment to move any materials not relatedto or designated for the selected carcass-disposalmethods.Thoroughly clean <strong>and</strong> disinfect the partsof equipment that have contacted disposalmaterials. Use an EPA-registered disinfectant<strong>and</strong> follow all label directions.2929

ProceduresGeneral ConsiderationsFigure 5. Two views of loading poultry carcasses into plastic-lined containers for transportationto a disposal site. (Courtesy of Kent Munden, USDA-APHIS, Clifton, TX).30

TransportationTo transport carcasses from an affected areato the disposal site, use planned travel routes tolimit human exposure <strong>and</strong> disease transmission<strong>and</strong> minimize negative public perception.Obtain any required permissions for personnelhauling dead animals commercially. Statessuch as Georgia require that such permits beobtained from the State Department of Agriculture.Use cleanable containers, such as drop-offcontainers or front-dump container trucks, forloading the carcasses <strong>and</strong> transporting them tothe disposal site (Fig. 6). Bring the empty containersback to the loading area.Resources available to help with planningtransportation routes in response to large-scaleevents include the U.S. Department of Energy’sTransportation Routing Analysis GeographicInformation System (https://tragis.ornl.gov).Provide a separate exit for moving the infectedcarcasses out of an animal feeding operation.Pick up any nondiseased carcasses within72 hours of the animals’ demise.Infected bird carcasses such as those infectedwith avian influenza should be transferredfrom the affected premises to off-site locationsif on-site disposal is deemed not feasible or desirable.Use leak-proof containers. After loadingthe carcasses into containers lined with materialssuch as polyethylene plastic sheets, coverthe containers to prevent odor problems, diseasetransmission, <strong>and</strong> negative public perception(Figs. 7 <strong>and</strong> 8).Protect the drivers <strong>and</strong> operators from contaminationby disinfecting the cabins, lockers,clothing, <strong>and</strong> footwear. Use an EPA-registereddisinfectant to decontaminate the trucks as theyleave the event site to travel to the disposal site.3131

ProceduresGeneral ConsiderationsFigure 6. Views of a completely sealed mobile container (A), a mechanical loadingsystem (B), a drop-off container (C), <strong>and</strong> a front-dump truck (D) used to temporarily store<strong>and</strong> transport biomass materials (Courtesy of Kent Munden, USDA-APHIS, Clifton, TX).ABCD32

Supervise the departure of the transportvehicles from the farm, their travel routes,<strong>and</strong> their arrival at the disposal plant or site.Provide an escort vehicle carrying first-aidequipment, additional plastic covers, <strong>and</strong>emergency equipment to assist carcass transportationvehicles during travel emergencies.Ask for a designated government representativeto accompany the transport vehicles forbiosecurity reasons.Guard the carcass load against possiblethefts by terrorists seeking to cause harm,spread disease, or spread contamination.To limit vehicle refueling <strong>and</strong> minimizethe number of stops needed, select a disposalsite near the disease site.Carcasses should be removed quickly <strong>and</strong>properly. Always consider that the spread ofpathogenic microorganisms during routinepickup <strong>and</strong> transportation of dead animals to adisposal site presents a substantial threat.If the average temperature of the containerrises above 70 ºF, do not transport the deadanimals for rendering to sites more than 150miles away.3333

ProceduresGeneral ConsiderationsFigure 7. Two views of plastic-lined trailers before <strong>and</strong> after they were filled with poultrycarcasses. Note the plastic sheets to cover the carcasses (after the trailer was filled) for biosecurityduring hauling <strong>and</strong> transportation. (Courtesy of Kent Munden, USDA-APHIS, Clifton, TX).34

Figure 8. A view of the decontamination <strong>and</strong> covering process of a transporting truck containinginfected poultry carcasses (Courtesy of Kent Munden, USDA-APHIS, Clifton, TX).Figure 7. Two views of plastic lined trailers before <strong>and</strong> after filling with poultry carcasses. Note,the plastic sheets to cover carcasses (after filling) for bio-security during hauling <strong>and</strong>transportation <strong>and</strong> one view of decontamination <strong>and</strong> covering process of a transportingtruck containing infected poultry carcasses (Courtesy of Kent Munden, USDA-APHIS,Clifton, Texas).3535

Safety <strong>and</strong> BiosecuritySafety programsThe major focus of a safety program is toprevent deaths <strong>and</strong> to minimize the incidence<strong>and</strong> severity of injuries to workers engagedin waste-disposal operations, including thedisposal of contaminated plant <strong>and</strong> animalmaterials. Safety programs involve the use ofadministrative controls, engineering controls,<strong>and</strong> personal protective equipment.When administrative <strong>and</strong> engineeringcontrols—either alone or in combination—donot achieve the required level of personnelsafety, use personal protective equipment tominimize the workers’ exposure to contaminantsor disease agents. This equipment limitsthe disease agents’ contact with body surfaceareas, reducing the likelihood of injury or illness<strong>and</strong> the spread of the disease agents.Use administrative <strong>and</strong> engineering controlsas much as possible to manage safety;personal protective equipment should be usedonly as a last resort. The use of personal protectiveequipment, particularly for respiratoryprotection, carries a significant administrativeburden in that the workers wearing respiratorsshould be medically qualified, be fit-tested usingthe masks they intend to wear on site, <strong>and</strong>undergo ongoing medical monitoring, bothon- <strong>and</strong> off-site.36

Administrative controlsEstablish a perimeter around the disposalsite. Regardless of the perimeter’s design,carefully plan a lane through which thepersonnel can decontaminate themselves <strong>and</strong>their vehicles <strong>and</strong> equipment to reduce thespread of the pathogens.The perimeter should have only one entrance<strong>and</strong> one exit. The entrance <strong>and</strong> exit sitesmay be in the same location, or they may beseparated so that the contaminated material isbrought in on a “dirty” side, <strong>and</strong> ash or sanitizedwaste is removed from a “clean” side.Use access rosters to limit the number ofpersonnel working on site to the minimumnecessary to complete a given task.When developing an access roster, consider:• The medical, physical, <strong>and</strong> professionalqualifications required• Any need for personal protective equipment• The scope <strong>and</strong> size of the disposal task• The number of qualified personnelavailableEarly in the planning <strong>and</strong> initial phases ofthe operation, you must establish, clarify, <strong>and</strong>enforce the rules for who may enter <strong>and</strong> exit,<strong>and</strong> how, when, <strong>and</strong> where the entry <strong>and</strong> exitmay take place. Stress these rules continuallythroughout the operation. Controlling thevisitors <strong>and</strong> workers assigned to the site is ofparamount importance, both to ensure personnelsafety <strong>and</strong> to avoid spreading diseases.3737

Safety <strong>and</strong> BiosecurityHealth <strong>and</strong> safety planThe U.S. Occupational Safety <strong>and</strong> HealthAdministration (OSHA), through the HazardousWaste Operations Program (HAZWOPER),has set requirements <strong>and</strong> recommendations forpeople engaged in hazardous waste operationsinvolving disease-causing organisms. (Codeof Federal Regulations, Part 21, Chapter 1910,http://www.osha.gov/SLTC/hazardouswaste/index.html).When developing a health <strong>and</strong> safety plan,refer to the OSHA st<strong>and</strong>ard, but also consultwith experienced <strong>and</strong> qualified personnelbefore any incident response occurs. Personnelsuch as those possessing current OSHAHAZWOPER certifications of at least thetechnician level are qualified to develop health<strong>and</strong> safety plans for large, elaborate disposaloperations using many personnel. A commonsource of such people is the local fire department.Information on this credential is availableat or through the Academy of CertifiedHazardous <strong>Materials</strong> Managers (http://www.achmm.org).The health <strong>and</strong> safety plan is an importantdocument for worker protection <strong>and</strong> must begiven careful thought. It should be developedas part of the pre-incident planning phase <strong>and</strong>refined as the situation is further assessed.38

Engineering controlsDecontamination lanes <strong>and</strong> protocolsYou can greatly reduce the likelihood ofdisease spread by decontaminating workers<strong>and</strong> equipment before they exit the disposalsite. Although decontamination protocolsvary, all should consider at least three aspects:Decontamination procedures, processes<strong>and</strong> technologies: First, include thedecontamination procedures, processes, <strong>and</strong>technologies that have been determined to beeffective or are recommended by an appropriateFederal <strong>and</strong>/or State regulatory agency.For example, use disinfectants registeredby the U.S. Environmental Protection Agency(EPA) to clean <strong>and</strong> disinfect hard, nonporoussurfaces of equipment, vehicles, farm premises,<strong>and</strong> personal protective equipment. Ifa foreign animal disease is involved, EPAregistereddisinfectants may be available foruse; if not, the U.S. Department of Agriculture(USDA) <strong>Animal</strong> <strong>and</strong> <strong>Plant</strong> Health InspectionService has exemptions in place allowing certaincommon chemicals to be used for a widerange of foreign animal diseases.Use the decontamination agents that havebeen licensed under the Federal Insecticide,Fungicide, <strong>and</strong> Rodenticide Act (FIFRA) foruse on the specific organism of concern. Thelicensing process includes application methodsto ensure that the decontamination is effective.If not enough of the decontaminationagent is available for that particular pathogen,you will need to use a decontaminant forwhich the EPA has issued either an exemptionor a registrationThe choice of decontamination agentshould be based on the organism or pathogenof concern, the availability of decontaminationsolutions, the logistics of acquiring<strong>and</strong> disposing of either raw or diluted waste3939

Safety <strong>and</strong> Biosecuritygenerated from the decontamination process,<strong>and</strong> the contact time (the amount of timerequired for the decontamination solution toremain in place on the equipment or personnelfor maximum effectiveness). Table 3 providesguidance on choosing decontamination agentsbased on these factors.Support requirements for the decontaminationprocess: Often, especially inlarger operations, the personnel performingthe actual disposal operations must focus onthose tasks exclusively, with little time to conductdecontamination operations as well.In disposal operations requiring higherlevels of personal protective equipment (suchas OSHA Level B, in which air-supplyingrespirators are used), the amount of time thatworkers may spend on site is restricted bythe rate at which they use pressurized breathingair. This period is generally less than 45minutes.40

Table 3. EPA-approved pesticides (disinfectants) for use against highly pathogenic diseases.Disease ProductAfrican horse sicknessNone registered 1African swine feverLow Ph Phenolic 256Pheno Cen Germicidal DetergentKlor-KleenVirkon SAkabaneNone registeredAvian influenzaOdo-Ban Ready-to-UseOdo-BanJohnson’s Forward CleanerJohnson’s Blue Chip Germicidal Cleaner forHospitalsBTC 2125 M 10% SolutionNP 4.5 (D&F) Detergent/DisinfectantScented 10% BTC 2125M DisinfectantBTC 2125 M 20% SolutionQuat 44Quat RinseSpray NineDiseaseProduct(continued) Marquat 256Marquat 128Marquat 64Maquat 10Maquat 20-MMaquat 50DSMaquat 10 FQPAMaquat 256 EBCMaquat 128 EBCMaquat 64 EBCMaquat MQ2525M-14Maquat 10-BMaquat FPMaquat 256 PDD-125Public PlacesPublic Places ToweletteCCX-151D-128PJW-622(Continued on next page)4141

Safety <strong>and</strong> BiosecurityTable 3. (Continued).Disease Product(continued) Opticide-3Opticide-3 WipesDisinfectant DC 100Sterilex Ultra Disinfectant CleanerHI-Tor Plus Germicidal DetergentMarquat 256-NHQMaquat 2420 CitrusFormulation HS-652QFormulation HS-821QHS-867QHS-867Q Germicidal Cleaner <strong>and</strong> DeodorantFormulation HH-652 QVirex II/128Virex II Ready to UseVirex II 64Virex 11/256VirocideUcarcide 14 AntimicrobialUcarcide 42 AntimicrobialUcarsan 442 SanitizerDisease(continued)ProductUcarsan 414 SanitizerSynergizeMaxima 128Maxima 256Broadspec 256Maxima RTUQ5.5-5.5NPB-2.5HWSanox II7.5% BTC 885 Disinfectant/SanitizerQuik ControlBardac 205M-7.5BLonza Formulation Y-59Lonza Formulation S-21Lonza Formulation S-18Lonza Formulation R-82Lonza Formulation S-18FLonza Formulation R-82FLonza Formulation S-21FLonza Formulation DC-103(Continued on next page)42

Table 3. (Continued).Disease Product(continued) Bardac 205M-50Bardac 205M-10Bardac 205M-1.30Bardac (R) 205M-14.08Bardac 205M-2.6Bardac 205M-5.2Microban QGCMicroban ProfessionalMaquat MQ651-ASMaquat 615-HDMaquat 5.5-MMaquat 7.5-MMaquat 86-MMaquat 750-MMaquat 710-MMaquat ADC & R DisinfectantBiosolHusky 806 H/D/NPheno Cen Germicidal DetergentPheno-Cen Spray Disinfectant/DeodorantDiseaseProduct(continued) Low Ph Phenolic 256Phenocide 256Phenocide 128Phenolic Disinfectant HGTek-Trol Disinfectant Cleaner ConcentrateAdvantage 256 Cleaner DisinfectantDeodorantLPH Master ProductSporicidin Br<strong>and</strong> Disinfectant SolutionUcarsan Sanitizer 420Ucarsan Sanitizer 4128Accel TBVirkonOxonia ActiveOxySept LDIPeridoxVortexxDisinFxDyne-O-MightVirkon S(Continued on next page)4343

Safety <strong>and</strong> BiosecurityTable 3. (Continued).DiseaseProduct(continued) Klor-KleenCloroxDispatch Hospital Cleaner with BleachDispatch Hospital Cleaner Disinfectant Towelswith BleachCPPC Ultra Bleach 2CPPC StormAseptrol S10-TabsBovine babesiosisNone registeredBluetongueNone registeredBorna diseaseNone registeredBovine ephemeral feverNone registeredBovine parafilariasisNone registeredBovine spongiform encephalopathyNone registeredDisease ProductClassical swine fever (“hog cholera”)Pheno Cen Germicidal DetergentPheno-Cen Spray Disinfectant/DeodorantTri-CenQ5.5-5.5NPB-2.5HWLow Ph Phenolic 256Ucarsan Sanitizer 420Ucarsan Sanitizer 41281-Stroke EnvironFort Dodge Nolvasan SolutionFort Dodge Nolvasan SVirkon SKlor-KleenContagious agalactia of sheep <strong>and</strong> goatNone registeredContagious bovine pleuropneumoniaNone registeredContagious caprine pleuropneumoniaNone registered(Continued on next page)44

Table 3. (Continued).Disease ProductContagious equine metritisNone registeredDourineNone registeredDuck virus hepatitisNone registeredEpizootic lymphangitisNone registeredEquine encephalosisNone registeredFoot-<strong>and</strong>-mouth disease 3Low PH Phenolic 256Oxonia ActiveOxysept LDILonza DC 101Aseptrol S10-TABAseptrol FC-TabVirkon SGetah virus diseaseNone registeredGl<strong>and</strong>ersNone registeredDisease ProductHeartwaterNone registeredHendra Virus DiseaseNone registeredHemorrhagic SepticemiaNone registeredInfectious salmon anemiaVirkon S 4Japanese encephalitisNone registeredJembrana diseaseNone registeredLouping IIINone registeredLumpy skin diseaseNone registeredMalignant catarrhal feverNone registeredNairobi sheep diseaseNone registered(Continued on next page)4545

Safety <strong>and</strong> BiosecurityTable 3. (Continued).DiseaseNewcastle diseaseProductVesphene II SELPH Master ProductVesta-Syde Interim InstrumentDecontamination SolutionProcess Vesphene II STAmerse IIBeaucoup Germicidal DetergentMatar II1-Stroke EnvironTek-Trol Disinfectant Cleaner ConcentrateBio-Phene Liquid DisinfectantPhenocide 256Phenocide 128Phenolic Disinfectant HGMikro-QuatOdo-Ban Ready-to-UseOdo-BanJohnson Blue Chip Germicidal Cleaner forHospitalsDisease(continued)ProductGrenadierBTC 2125M 20% SolutionMaquat 10Maquat 20-MMaquat 50DSMaquat 10-PDMaquat 256 EBCMaquat 128 EBCMaquat 64 EBCMaquat MQ2525M-CPVMaquat MQ2525M-14Maquat 10-BMaquat FPMaquat 256 PDD-125Public PlacesPublic Places ToweletteCCX-151(Continued on next page)46

Table 3. (Continued).DiseaseProduct(continued) Bioguard 453GemstoneHospital Disinfectant CleanerMaquat 2420-CitrusFormulation HS-652QFormulation HS-821QFMB 1210-5 QuatHL-867 QHS-267Q Germicidal Cleaner <strong>and</strong> DisinfectantFMB 1210-8 Quat Concentrated GermicideFormulation HS-1210 Disinfectant/Sanitizer(3.85%)Formulation HS-1210 Disinfectant/Sanitizer(50%)Formulation HS-1210 Disinfectant/Sanitizer(14.08%)Virex II/128Virex II Ready to UseVirex II 64Virex II/256Biosentry 904Process NPDDisease(continued)ProductBardac 205M-7.5BLonza Formulation S-21Lonza Formulation S-18Lonza Formulation R-82Lonza Formulation S-18FLonza Formulation R-82FLonza Formulation S-21FLonza Formulation DC-103Bardac 205M-50Bardac 205M-10Bardac 205M-1.30Bardac (R) 205M-14.08Bardac 205M RTUBardac 205M-2.6Bardac 205M-5.2Bardac 205M-23Maquat MQ615-ASMaquat 615-HDMaquat 5.5-MMaquat 7.5-M(Continued on next page)4747

Safety <strong>and</strong> BiosecurityTable 3. (Continued).DiseaseProduct(continued) Maquat 86-MMaquat 750-MMaquat 710-MMaquat AKP 3510Quick ControlMicroban QGCMicroban Professional Strength Multi-PurposeAntibacterial CleanerDC & R DisinfectantFort Dodge Nolvasan SolutionNolvasan SUcarsan Sanitizer 420Ucarsan Sanitizer 4128MikrokleneMikroklene DFOxonia ActiveOxysept LDIVirkon SKlor-KleenDisease ProductNew world screwworm (“screwworm”)Champion Insecticide SprayBlack Jack Multipurpose 0.5% InsecticideSunbugger Flea & Mite SprayCT Residual SprayPermethrin Insecticide SprayPermanone Multi-Use Insecticide SprayCo-Ral Coumaphos Flowable InsecticideCo-Ral Fly <strong>and</strong> Tick SprayNipah virus diseaseNone registeredPeste des petits ruminantsNone registeredRabbit calicivirus diseaseNone registeredRift Valley feverNone registeredRinderpestNone registered(Continued on next page)48

Table 3. (Continued).Disease ProductSheep <strong>and</strong> goat poxNone registeredSpring viremia of carpNone registeredSwine vesicular diseaseNone registeredTrypanosomosisNone registeredTheileriosisNone registeredVenezuelan equine encephalomyelitisNone registeredDisease ProductVesicular exanthema of swineAlcide Br<strong>and</strong> LD 10:1.1 BaseVirkon SKlor-KleenVesicular stomatitisAlcide Exspor 4:1:1 - BASEAlcide Br<strong>and</strong> LD 10:1.1 BASED-125Virkon SBio-Phene Liquid DisinfectantBiosentry 904Wesselsbron diseaseNone registered1“Registered” refers to a FIFRA Section 3 registration.2Products listed for use against avian influenza were not generated from the National Pesticide Information Retrieval System (NPIRS)database. This list originated with the EPA’s “Registered Antimicrobial Products with Label Claims for Avian (Bird) Flu Disinfectants”list dated July 13, 2007, located at: http://www.epa.gov/pesticides/factsheets/avian_flu_products.htm.3Products listed for use against foot-<strong>and</strong>-mouth disease (FMD) were not generated from the NPIRS database. This list originatedfrom EPA’s 8/8/07 FMD table provided via e-mail to APHIS.4Product is not listed in NPIRS as approved for use against this virus, but the use does appear on the federally approved label.Source: Information provided by the U.S. Department of Agriculture, <strong>Animal</strong> <strong>and</strong> Health Inspection Service, 9-25-07.4949

Safety <strong>and</strong> BiosecurityDisposal of the hazardous waste generatedfrom the decontamination process:All disposable protective clothing must bediscarded before the workers exit the site.After the clothing has been collected, it mustbe incinerated or autoclaved to prevent thespread of disease.Decontamination protocols should bedeveloped or selected by appropriately trainedpersonnel (HAZWOPER-certified or equivalent).Work zonesAt least five types of worksites should beestablished (Fig. 9):Site perimeter <strong>and</strong> work zones: Theestablishment <strong>and</strong> maintenance of the workzone described in this guide are intended tomeet the requirements of the OSHA HAZ-WOPER st<strong>and</strong>ard. As discussed in the Administrativecontrols section, a work zone isestablished to:• Reduce the accidental spread of hazardoussubstances by workers or equipment• Confine work activities to the appropriateareas• Facilitate the location <strong>and</strong> evacuation ofpersonnel in case of emergencyExclusion zone: The area where contaminationis present. In this guide, it is the areawhere contaminated animal <strong>and</strong> plant materialsare placed for disposal.Contamination reduction zone: Thetransition zone between the contaminated area<strong>and</strong> the clean area.Support zone: The uncontaminated areawhere workers should not be exposed to contaminatedmaterials or conditions. This area is50

an appropriate location for the comm<strong>and</strong> post.Contamination reduction corridor: Anarea with at least two lines of decontaminationstations, one for personnel <strong>and</strong> one forequipment (see the Decontamination section).Access control points are physical orvirtual “gates” that control the flow of workers<strong>and</strong> equipment in <strong>and</strong> out of the exclusionzone (Fig. 9).Establish the comm<strong>and</strong> post <strong>and</strong> contaminationreduction corridor upwind of the exclusionzone. Given that some disposal operationsmay continue for days <strong>and</strong> that the winddirection may change, you may use historicalwind data (available from an area meteorologist)for planning purposes to obtain the mostprobable wind direction for a particular seasonin a specific geographical region.Figure 9. A schematic of decontaminationarea containing appropriate work sites.Exclusion zoneContaminationreduction zoneSupport zoneArea dimension is not to scale.ContaminationreductioncorridorHotlineContaminationcontrol lineAccesscontrol pointsComm<strong>and</strong>postPrevailing wind directionFor information, refer to EPA publication 9285.2–15FS,contact your EPA Regional Office, or consult with aHAZWOPER-certified technician, often found in largermunicipal fire departments.5151

Safety <strong>and</strong> BiosecuritySecurityThe physical construction of a boundaryor perimeter is an engineering control. Thelevel of physical security required for a particularoperation depends largely on:• The scope of the disposal process• The length of time the disposal operationwill be at a particular location• The likelihood of scavengers or curiouspeople venturing onto the site• The availability of appropriate fencingmaterialFor example, thermal destruction of alarge number of cattle using a low-throughputtechnique may necessitate the piling ofcarcasses on site until they can be destroyedappropriately.The importance of protecting the diseasedcarcasses from scavenging mammals<strong>and</strong> birds cannot be overstated, especiallyfor cases in which the diseases are caused bypathogens highly resistant to environmentaldegradation, such as in the case of foot-<strong>and</strong>mouthdisease.52

Contamination reduction corridorDecontaminating workers <strong>and</strong> equipmentbefore they exit the disposal site greatlyreduces the likelihood of disease spread tounaffected animals at other sites. In the caseof zoonotic diseases, it can also prevent thespread of disease to humans.Although decontamination protocolsvary, all should consider the decontaminationprocedures, processes, <strong>and</strong> technologies; thedisposal of the hazardous waste generatedfrom those processes; <strong>and</strong> personnel.As discussed in the Engineering controlssection, it is important that you use decontaminationprocedures, processes, <strong>and</strong> technologiesthat have been determined to be effectiveor are recommended by an appropriate federal<strong>and</strong>/or state regulatory agency. Use FIFRAlicenseddecontamination agents for useon the specific organism of concern. If notenough of the decontamination agent isavailable for that particular pathogen, a crisisexemption will be needed from the EPA to useanother decontaminant.The decontamination process requiressupplies <strong>and</strong> equipment. During the eventplanning phase, stockpile supplies <strong>and</strong> decontaminationsolutions. See Table 4 for potentialrequirements. The importance of logisticsplanning well before an event to obtain decontaminationsupplies <strong>and</strong> equipment cannot beoverstated.The disposal of hazardous waste generatedfrom the decontamination process entails thoroughlydecontaminating the nondisposableitems or equipment before removing themfrom the worksite. Before exiting the con-5353

Safety <strong>and</strong> Biosecuritytamination reduction corridor, workers shoulddiscard or store in appropriate containers(such as lidded rubber trash cans lined with8-mil garbage bags) all disposable equipment<strong>and</strong> protective clothing.As discussed in the Engineering controlssection, incinerate or autoclave all disposableclothing <strong>and</strong> equipment to prevent the spreadof disease.Note: The runoff from the contaminationreduction zone is contaminated <strong>and</strong> should becollected <strong>and</strong> disposed of according to local,State, <strong>and</strong> Federal environmental regulationsin coordination with local, State, <strong>and</strong> Federalofficials <strong>and</strong> guidelines.PersonnelThe personnel required for 24-hour continuousoperations should include at least twoteams of 10 people each, working in either two12-hour shifts or four 6-hour shifts. <strong>Guide</strong>linesfor the use of personnel in decontaminationoperations are highlighted in Table 5.The decontamination of personnel—especiallywhen higher levels of protection <strong>and</strong>personal protective equipment are used—is amajor consideration <strong>and</strong> requires additionalpersonnel beyond those used for actual disposaloperations. Likewise, medical monitoringby an emergency medical technician orparamedic is advised <strong>and</strong>, in some operations,required by law.54

Table 4. Team equipment planning (modified from the National <strong>Animal</strong>Health Emergency Management System’s “Operational <strong>Guide</strong>lines for Cleaning<strong>and</strong> Disinfection,” Draft, November 2005).EquipmentNondisposable items(per team)Disposable items(per team-day 1 )Decontamination equipmentPower spray unit <strong>and</strong> tank 2Spray nozzles 4Safety can (5 gal with gas) 2Hose (¾ in x 50 ft) 5Garbage bags (8 mil; 50 gal) 20Pressurized garden sprayers 4Safety equipmentPressure eyewash station (alkaline hydrolysis) 1Disposable eyewash bottles 1Bottled water (2 gal/person/day) 20First aid kit 0.5Stretcher/litter 0.5Miscellaneous equipmentMulti-tool with knife blade 10This team equipment planning table assumes two teams of 10 people each in a 24-hour period, eachworking a 12-hour shift.1Team-day is the number of units one team will use in a 12-hour day, based on the assumptions above.5555

Safety <strong>and</strong> BiosecurityTable 5. <strong>Guide</strong>lines for the use of personnel in decontamination operations.Function# PeoplerequiredEstimated timerequiredDry removal of straw <strong>and</strong> other materials from the equipment; physical removal4 10 minof mud, blood, <strong>and</strong> other materialsHigh-pressure rinse 4 10 minDetergent application <strong>and</strong> soak time 4 20 minFinal rinse 4 10 minDrip-dry 0 10 minApplication of decontaminant/disinfectant 4 10 minEmergency medical monitoring (people not conducting decontamination2 n/afunctions)Backup (people suited up <strong>and</strong> ready to enter the contamination reduction zone2 n/ato serve as rescue personnel; they should remain at rest unless needed)Total 12 70 minText in blue indicates the functions that can be conducted simultaneously so that the workers conducting the high-pressure rinsecan immediately follow those performing dry removal as it is completed on a particular area or component of machinery.56

Decontamination guidelinesDecontamination protocols should bedeveloped or selected by qualified personnel(HAZWOPER-certified or equivalent). Themajor considerations in decontaminatingequipment <strong>and</strong> personnel follow.VehiclesTo keep the transport as clean as possible,thoroughly spray the animal carcasses withwater or water mixed with detergent to removeas much gross filth as possible before loadingthem into the vehicles.Line each vehicle with a tarp, such as an 8-mildisposable polyethylene plastic sheet, <strong>and</strong> seal thetruck at the top. The plastic sheet(s) must be largeenough to cover the carcasses <strong>and</strong> to be securedto the sides <strong>and</strong> ends of the box or dumpster.Place a layer of an absorbent material, suchas wood shavings or sawdust, on top of theplastic liner to prevent punctures, such as by thehorns or hooves.After transport, disinfect all the trucks,trailers, <strong>and</strong> other equipment used to transportthe diseased carcasses or materials. If a vehiclemust enter the exclusion zone, it must be completelydecontaminated through the contaminationreduction zone before leaving the site. Theminimum equipment necessary for adequatedecontamination includes:• Long-h<strong>and</strong>led, stiff bristle brushes• 5-gallon buckets half-filled with an appropriatedisinfectant• Appropriate personal protective equipment(see the planning guidelines for personalprotective equipment)• Containers for mixing the disinfectants<strong>and</strong>/or decontaminants• High-pressure, heated-water sprayers (at200 psi) for physically removing mud,blood, soil, <strong>and</strong> other contaminants5757

Safety <strong>and</strong> BiosecurityDisinfect vehicles in this order:Step 1. Completely remove any straw,feed, wood chips, manure, or other dry matter,using shovels, forks, or similar tools, beforeapplying any liquid solution to the vehicle.Step 2. Use stiff brushes to dislodge anymud, blood, or animal parts from the wheels,tires, or other parts of the vehicle. Rinse themwith water at 100 to 115 °F (38 to 46 °C).Note: A visibly clean surface is absolutelynecessary before disinfection <strong>and</strong> decontaminationcan be effective.Step 3. Allow the vehicle to drip-dry forabout 10 minutes.Step 4. Spray down the entire vehicle withan appropriate disinfecting agent, allowing forappropriate soak times.Step 5. Rinse the vehicle again with waterat an increased temperature of 120 to 170 °F(49 to 77 °C).If the driver or any passengers exit thevehicle at either the disposal site or thecarcass/plant material pickup site <strong>and</strong> do notdecontaminate themselves before reenteringthe truck cab, disinfect the rubber floor mats,dashboard, steering wheel, gear stick, <strong>and</strong>seats. Spray an approved pesticide inside thecab of the vehicle to kill any insects that couldbecome vectors/vehicles for the disease.Before reentering the cab, all personnelshould remove any contaminated clothing <strong>and</strong>wash with antiseptic soap <strong>and</strong> water beforeleaving the site.If possible, maintain the biosecurityof the interior of the vehicle by providingenough ground personnel (such as those toopen tailgates) so that the driver need not exitthe vehicle at any time in the exclusion <strong>and</strong>contamination reduction zones.58

Other equipmentDisinfect all small equipment items usedin the work zone before removing them fromthe work zone. Do not use shovels, axes, hammers,stiff brushes, or other tools that havewooden h<strong>and</strong>les. Fiberglass or plastic componentsare much easier to decontaminate.Personnel decontaminationAll personnel who enter the work zonemust exit through the contamination reductioncorridor <strong>and</strong> be adequately decontaminated toavoid spreading disease agents off-site <strong>and</strong>, inthe case of zoonotic disease agents, to avoideither becoming a vector for a contagious diseaseor contracting the disease of concern.Figure 10 presents a layout for a multipurposedecontamination line <strong>and</strong> guidelines forsetting it up. However, multiple site-specificfactors should also be considered.The same decontamination protocol mustbe used for small equipment as for workers:All soil, mud, blood, <strong>and</strong> other contaminantsmust be physically removed with brushes <strong>and</strong>initially rinsed from the equipment. An appropriatedisinfection solution must be appliedat the proper volume, allowed adequate staytime <strong>and</strong> rinsed thoroughly with clean water.The green line represents the path takenby workers exiting the work zone through thecontamination reduction zone. The red linerepresents the path taken if a casualty occursin the work zone.Workers should follow this procedure forroutine (nonemergency) personnel decontamination:Step 1. If the outer gloves are made of asynthetic material <strong>and</strong> not of leather, rinse<strong>and</strong> disinfect them. If they are made of leather5959

Safety <strong>and</strong> Biosecurityor other liquid-permeable material, drop thegloves in a bucket for disposal or autoclaving.Step 2. Drop the equipment into the equipmentdrop basin, <strong>and</strong> clean <strong>and</strong> disinfect theequipment.Step 3. Step into the boot decontamination(decon) basin <strong>and</strong> remove any gross contaminationusing a stiff-bristled, long-h<strong>and</strong>ledbrush. Note: Use a “h<strong>and</strong> hold,” fashionedfrom T-posts, wood or other sturdy material atthe boot decon station. This will help preventfalls when workers are entering, st<strong>and</strong>ing in,<strong>and</strong> exiting the basin. Upon completion ofgross removal of contaminants, step out of thebasin, moving toward the area of least contamination(to the “clean” side of the contaminationreduction zone).Step 4. If the outer protective suit is notdisposable or is liquid permeable, step into thedecontamination shower area. If ample personnelare available, one person (dressed ina level of protection one level down from theworkers being decontaminated—for example,if the workers are in Level B, the decontaminationpersonnel may be in Level C) maydisinfect the other workers by using a simplepressurized garden sprayer filled with anappropriate disinfectant. This person shouldthoroughly cover the other workers’ outerprotective ensembles with the disinfectant <strong>and</strong>allow the recommended soak/stay time. Makeevery effort to avoid getting disinfectant sprayon the respirator. Note: Steps 4 <strong>and</strong> 5 are unnecessaryif the workers are wearing disposableouter protective suits.Step 5. Step into the rinse shower, whereall disinfectant is removed with clean water.Step 6. Disinfect <strong>and</strong> rinse the outergloves, then step into the boot disinfectionbasin. The workers should step to the tank ex-60

change area if they are wearing OSHA LevelA or B gear <strong>and</strong> are planning to reenter thework zone without undergoing full decontamination.Step out of the basin moving towardthe area of least contamination (to the cleanside of the contamination reduction zone).Step 7. Remove the outer protective garment<strong>and</strong> discard it into an approved container.Remove this outer garment from the insideout to avoid contaminating the skin or theinner set of clothing items. Providing anotherworker to assist in this process in the deconline will not only help prevent contaminationbut will also assist the workers who mayalready be physically <strong>and</strong> mentally exhausted.Step 8. Remove the inner gloves.Step 9. Remove the inner suit (if one isworn).Step 10. Remove the respirator (if one isused) <strong>and</strong> place it in an approved container fordisposal or reuse. Step across the contaminationcontrol line.6161

Safety <strong>and</strong> BiosecurityFigure 10. Schematic of a multipurpose decontamination line.1Glovedecon/rinse2Equipmentdrop3Hot lineGross boot decon basinH<strong>and</strong> holdContaminationreduction zone4Decon showerEmergency decon line5Rinse showerFirst aid/cut outequipmentOuter glove decon/rinse6Tank exchange (Levels A/B)H<strong>and</strong> holdOutersuit dropLiquid control lineWinddirection78Innerglove drop910Inner suitdropH<strong>and</strong> decon/rinseSCBA*/mask dropContamination control line*SCBA: Self-contained breathing apparatus62

Personal protective equipmentSeveral factors affect the process ofselecting an appropriate protective ensemble:the tasks being performed; the physical,chemical, <strong>and</strong> biological hazards to which theworkers are exposed; <strong>and</strong> the logistical supportthat must accompany a specific protectivelevel.For example, workers in thermal destructionoperations may require protection fromphysical hazards such as high heat <strong>and</strong> heavyequipment, from chemical hazards such asdecontamination solutions, <strong>and</strong> from biologicalagents such as aerosolized anthrax spores.One choice for an appropriate protective ensemblemight be OSHA Level C, which couldinclude the following:• A half- or full-facepiece air-purifyingrespirator with a filter that can removeanthrax spores. The respirator must beapproved by National Institute for OccupationalSafety <strong>and</strong> Health (NIOSH).Note: See 29 CFR 1910.134c for guidelineson establishing <strong>and</strong> maintaining arespiratory protection program.• Eye protection if a full facepiece respiratoris not used• Hooded, chemical-resistant coveralls• Outer <strong>and</strong> inner gloves that are chemicalresistant• Outer boots with chemical-resistantsteel toes <strong>and</strong> shanks• Outer boot covers that are disposable<strong>and</strong> chemical resistant• Hard hatHowever, for workers who might be requiredto enter confined spaces or areas of lowoxygen concentration or high concentrationsof toxic gases, the ensemble should includea positive-pressure, full-facepiece, self-containedbreathing apparatus (SCBA), or a posi-6363

Safety <strong>and</strong> Biosecuritytive-pressure-supplied air respirator (air line)with an escape SCBA (OSHA Level B). Asa final option, consider selecting a suppliedairrespirator because the logistics burden ofmaintaining an adequate <strong>and</strong> safe air supply<strong>and</strong> the added physical burdens of carrying airtanks are great.Specific recommendations for personalprotective equipment are highlighted undereach disposal method.Equipment planning factorsTables 4, 6, <strong>and</strong> 7 list the recommendedequipment to ensure health <strong>and</strong> safety indisposal operations. Note that if a catastrophicoutbreak of plant or animal disease occurs,certain pieces of personal protective equipmentmay be difficult to obtain. If space <strong>and</strong>resources are available, acquire <strong>and</strong> store a 5-to 7-day supply of basic items such as gloves<strong>and</strong> boots.The data in these tables assume 24-houroperations <strong>and</strong> 12-hour shifts each day. Theseestimates account for the occasional equipmentfailure (such as torn gloves or boots),excessively contaminated or damaged personalprotective equipment that must bedestroyed instead of reused, <strong>and</strong> the inevitableunknown incident that occurs during any hazardouswaste disposal operation. These tablesare meant to serve as guidelines <strong>and</strong> are notcomprehensive for most operations.64

Figure 11. Four levels of personal protective equipment.Level ALevel A affords the greatest level of skin, respiratory,<strong>and</strong> eye protection:• A positive-pressure, full-facepiece, self-containedbreathing apparatus or a positive-pressuresuppliedair respirator with an escape selfcontainedbreathing apparatus, approved byNIOSH• A totally encapsulating chemical-protective suit• Coveralls 1• Long underwear 1• Outer chemical-resistant gloves• Inner chemical-resistant gloves• Chemical-resistant boots withsteel toes <strong>and</strong> shanks• Hard hat (under the suit). 1• Disposable protective suit,gloves, <strong>and</strong> boots (dependingon the suit construction, itmay be worn over a totallyencapsulating suit)1Optional, as applicableLevel BLevel B offers the highest level of respiratoryprotection but a lesser level of skin protection:• A positive-pressure, full-facepiece, selfcontainedbreathing apparatus or a positivepressure-suppliedair respirator with an escapeself-contained breathing apparatus (NIOSHapproved)• Hooded chemical-resistant clothing (overalls, along-sleeved jacket, coveralls, a one- or two-piecechemical-splash suit, <strong>and</strong> disposable, chemicalresistantoveralls)• Coveralls 1• Outer chemical-resistant gloves• Inner chemical-resistant gloves• Chemical-resistant boots withsteel toes <strong>and</strong> shanks• Disposable, chemical-resistantouter boot covers• Hard hat• Face shield1Optional, as applicable(Continued on next page)6565

Safety <strong>and</strong> BiosecurityFigure 11. (Continued).Level CLevel C is used when the concentration(s) <strong>and</strong>type(s) of airborne substance(s) are known <strong>and</strong> thecriteria for using air-purifying respirators are met:• Full-face or half-mask air-purifying respirators(NIOSH approved)• Hooded, chemical-resistant clothing (overalls, along-sleeved jacket, coveralls, a one- or two-piecechemical-splash suit, <strong>and</strong> disposable chemicalresistantoveralls)• Coveralls 1• Outer chemical-resistant gloves• Inner chemical-resistant gloves• Outer, chemical-resistant bootswith steel toes <strong>and</strong> shanks• Outer disposable, chemicalresistantboot covers 1• Hard hat 1• Escape mask 1• Face shield 11Optional, as applicableLevel DLevel D is a work uniform affording minimalprotection; it is used for nuisance contaminationonly:• Coveralls 1• Gloves 1• Outer, chemical-resistant boots/shoes with steeltoes <strong>and</strong> shanks• Outer, chemical-resistant boots• Safety glasses or chemical splash goggles• Hard hat 1• Escape mask 1• Face shield 11Optional, as applicable66

Table 6. Personal protective equipment planning.EquipmentH<strong>and</strong> protectionLeather gloves (specific to work)Gloves (heavy butyl rubber)Gloves (nitrile; worn under leather)Foot protectionSteel toe/steel shank leather work bootsSteel toe/steel shank butyl rubber bootsHead protectionNondisposable items(per team)2 pairs2 pairsHard hat 1Waterproof hat 1Respiratory protectionSCBA positive-pressure respirator 1Supplied-air positive-pressure respirator 1Air-purifying respirator 1Powered air-purifying respirator 1Disposable items(per person-day 1 )4 pairs1–2 pairs10–12 pairsFilter cartridges for respirators 0.25Disposable N95/N100 respirators 4–6(Continued on next page)6767

Safety <strong>and</strong> BiosecurityTable 6. (Continued).EquipmentChemical protective overgarmentNondisposable items(per team)Butyl rubber apron 2Protective eyewearIndirectly vented chemical gogglesSafety glasses (with side shields)2 pairs2 pairsPolystyrene face shield (caustic solutions) 1Hearing protectionDisposable earplugsEarmuffsProtective suit (Tyvek, cloth or other material)2 pairsDisposable items(per person-day 1 )4–6 pairsDisposable (Level C or D) 3Decontaminable (Level A or B) 2Spare clothingSurgical scrubs or disposable protective suitsSpare pair of shoes (supplied by workers)Miscellaneous equipment1 pairMulti-tool with knife blade 12 sets1Person-day is the number of units one person will use in a day, based on the assumptions above.68

Table 7. Recommended tools for a crew of 10 people (Modified from the National <strong>Animal</strong>Health Emergency Management System’s “Operational <strong>Guide</strong>lines for Cleaning <strong>and</strong> Disinfection,”Draft, November 2005).EquipmentNondisposableitems (per team)Claw hammer 2Pliers 2Screwdriver (2 flathead; 2 Phillips) 4Adjustable end wrench 2Crowbar/wrecking bar 2Hatchet 2Axe 2Wire brush (with scraper nose) 24Fiber brush (long-h<strong>and</strong>led) 5Plastic bucket (5-gal) 6EquipmentNondisposableitems (per team)Sponge 24Tent 2Shovel (flat-billed) 4Broom (heavy) 3Shop vacuum 1Electrical cord (12-ga, 100 ft) 1Post hole digger 2Garden rake 2Fork (manure) 2Scraper (long-h<strong>and</strong>led) 26969

Safety <strong>and</strong> BiosecurityHeat-stress monitoring <strong>and</strong> measurementPortable heat-stress meters or monitorsare used to measure heat conditions. Theseinstruments can calculate both the indoor <strong>and</strong>outdoor wet-bulb globe temperature (WBGT)indexes, which consider the combined effectsof radiant heating from the sun, relativehumidity, <strong>and</strong> air temperature.With this measurement <strong>and</strong> informationon the type of work being performed, heatstress meters can help in determining thelength of time a person can safely work orremain in a particular hot environment. Theresultant data can provide guidance on work/rest cycles.In Table 8, examples of light work mightinclude the assembly of tools or clerical workdone in the operations center. Moderate workmight include the operation of heavy equipmentsuch as trucks <strong>and</strong> loaders. Heavy workwould include the physical manipulation ofcontaminated materials or the performance ofdecontamination operations on the ground.As an example, consider a worker wearingTyvek <strong>and</strong> performing moderate work. A theoreticalheat-stress meter provides a value of87 °F. Because the worker is wearing Tyvek,subtract 10.8 °F (Table 9) from the WBGTvalue of 87 °F, resulting in 76.2 °F.To stay within the permissible heat exposurethreshold limit value of 76.2 °F forworkers performing moderate work, accordingto Table 8 this person would need to beon a cycle of 25 percent work, 75 percent restfor each hour worked (15 minutes of work, 45minutes of rest).70

Table 8. Heat-stress monitoring during worker performance.Permissible heat exposure threshold limit valuesWork loadWork/rest regimen Light Moderate HeavyContinuous work 86 °F (30.0 °C) 80 °F (26.7 °C) 77 °F (25.0 °C)75% work, 25% rest, each hour 87 °F (30.6 °C) 82 °F (28.0 °C) 78 °F (25.9 °C)50% work, 50% rest, each hour 89 °F (31.4 °C) 85 °F (29.4 °C) 82 °F (27.9 °C)25% work, 75% rest, each hour 90 °F (32.2 °C) 88 °F (31.1 °C) 86 °F (30.0 °C)These values apply to physically fit <strong>and</strong> acclimatized individuals wearing light summer clothing. As contaminated materialdisposal operations will undoubtedly require heavier clothing that impedes sweat or has a higher insulation value, thepermissible heat exposure values above must be reduced by the corrections shown in Table 9.Source: OSHA Technical Manual, Section III, Chapter 4 (TED 01–00–015)Table 9. Wet-bulb globe temperature index correction factors for worker performancewhile wearing heavier protective clothing.Clothing typeWBGT 1 indexcorrection (°F)Summer lightweight working clothing (such as operations center personnel) 0Cotton coveralls (such as truck drivers) –3.6Winter work clothing (such as for operations in winter) –7.2Water barrier, permeable (such as workers wearing Tyvek or similar protective ensemble) –10.8Fully encapsulating suit, gloves, boots, <strong>and</strong> hood (such as OSHA Level A or B) –18.01WBGT: Wet bulb globe temperature7171

Safety <strong>and</strong> Biosecurity72Heat index: An alternative measureto assess conditions causing heat stressThe heat index shows the relationshipbetween the relative effects of temperature<strong>and</strong> humidity. The index can be used as asecond-choice approach if no heat stress meteror wet-bulb globe temperature thermometer isavailable. Use Table 10 only when a wet-bulbglobe temperature thermometer or heat-stressmeter <strong>and</strong> qualified operators are unavailable.As the heat index does not take into accountthe heat resulting from radiant energyfrom the sun, add a conservative estimate of15 ºF to the environmental temperature valuetaken from this chart when workers are indirect sunlight. After a value is identified inTable 10, use Tables 8 <strong>and</strong> 9 to obtain an estimateof the work/rest cycle.Sample calculation: The environmentalconditions at a disposal site are 80 ºF <strong>and</strong> 20percent relative humidity, with the workersin direct sunlight. The heat index value (obtainedfrom Table 10 <strong>and</strong> adding 10 ºF to theenvironmental temperature to account for thedirect sunlight exposure) is 87 ºF.According to Table 8, a worker dressed ina Tyvek suit with boots, gloves, <strong>and</strong> a hard hat(WBGT correction factor of -10.8 ºF) performingmoderate work would need a workrestcycle of 25 percent work/75 percent restfor each hour worked. Because of the personalprotective equipment correction factor of10.8 °F (Table 9), this worker can continuewith this work/rest cycle as long as the heatindex or wet-bulb globe temperature does notexceed 76.2 °F. For more information, visithttp://www.OSHA.gov.

Table 10. Heat index used as an alternative measure to assess conditions causing heat stress.70°(21)75°(24)80°(27)85°(29)90°(32)Heat indexEnvironmental temperature °F (°C)RelativehumidityApparent temperature ºF (C)0% 64 (18) 69 (20) 73 (23) 78 (26) 83 (28) 87 (31) 91 (33) 95 (35) 99 (37) 103 (39) 107 (42)10% 65 (18) 70 (21) 75 (24) 80 (27) 85 (29) 90 (33) 95 (35) 100 (38) 105 (41) 111 (44) 116 (47)20% 66 (19) 72 (22) 77 (25) 82 (28) 87 (30) 93 (33) 99 (37) 105 (41) 112 (44) 120 (49)30% 67 (19) 73 (23) 78 (26) 84 (29) 90 (33) 96 (36) 104 (40) 113 (45) 123 (51)40% 68 (20) 74 (23) 79 (26) 86 (30) 93 (34) 101 (38) 110 (43) 123 (56)50% 69 (20) 75 (24) 81 (27) 88 (31) 96 (36) 107 (42) 120 (49)60% 70 (21) 76 (24) 82 (28) 90 (33) 100 (38) 114 (46)70% 70 (21) 77 (25) 85 (29) 93 (34) 106 (41) 124 (51)80% 71 (22) 78 (26) 86 (30) 97 (36) 113 (45)90% 71 (22) 79 (26) 88Apparent temperatureHeat-stress risk with physical activity <strong>and</strong>/or prolonged exposure90–104 °F (32–40 °C) Heat cramps or heat exhaustion possible105–130 °F (31–54 °C) Heat cramps or heat exhaustion likely; heat stroke possibleAbove 130 °F (54 °C)Heat stroke very likely95°(35)100°(38)105°(41)110°(43)115°(46)120°(49)7373

CostEconomic factorsThe relevant economic <strong>and</strong> cost factorsto evaluate can be separated into direct <strong>and</strong>indirect costs (Tables 11 <strong>and</strong> 12).Direct costs involve direct disposal-General Considerationsrelated operations, transportation, facilities,energy, storage, <strong>and</strong> security.Indirect costs are related to increased diseaseincidence, environmental impacts, publicperception, <strong>and</strong> indirect income loss.74

Table 11. Direct costs incurred from installation <strong>and</strong> operating disposal activities.CategoryOperation costsFacilities, permitting<strong>and</strong> other capitalequipmentSecurityTransportationStorageExpense• Energy• Labor• Chemicals• Personal protective equipment• Decontamination equipment/chemicals• Cost of livestock or crops destroyed by disease, or to prevent spread of disease• Disposal of treatment residue (such as ash or finished compost)• Permit fees <strong>and</strong> legal costs for obtaining disposal sites• Hauling in facilities• Any portable disposal facilities adopted• Installing new disposal facilities• Labor• Fencing• Site entry/exit procedures/decontamination• Transporting animal carcasses or plants that must be moved• Loading/unloading• Leasing/ownership• Fuel• Labor• Educating truck operators/drivers/supervisors• Preventive activities, including livestock relocations, along the transport route to reduce thepossibility of disease spread• Security associated with transport• Maintaining the carcasses or plants awaiting disposal• Security to keep out wildlife• Odor control• L<strong>and</strong>scape appearance maintenance7575

CostGeneral ConsiderationsTable 12. Indirect costs associated with disposal activities.CategoryExpenseDisease-related Added costs of infections spread by:• Leakage during transport of carcasses <strong>and</strong> contaminated plants• Incomplete decontamination• Wildlife incursion into the disposal operation• Disease management activities (such as vaccinations) to reduce the disposal-related costs to theenvironment <strong>and</strong>/or because of public perception• Security costs along the transportation routes if the carcasses are to be movedEnvironmental • Air pollution• Water pollution• Soil contamination• Loss of future returns to l<strong>and</strong> employed for disposal• Harm to wildlife <strong>and</strong>/or fisheriesPublic perception • Increased legal fees resulting from public opposition• Changes in income because of shifting public opinions resulting from disposal activities, includingreduced:– Tourism– Regional economic activity– Domestic meat sales– International meat export salesIncomeLoss of business in areas where disposal activities are undertaken or transport routes pass throughNote: Certain disposal methods may have unique indirect costs. For example, alkaline hydrolysis disposal incurs costs resultingfrom increased commission of support equipment because of alkaline exposure. Some methods may also incur additional indirectcosts because of soil disturbances <strong>and</strong> erosion caused by the operation of heavy machinery <strong>and</strong> trucks.76

ThermalDefinition <strong>and</strong> objectivesThe thermal method of managing contaminatedmaterials is the destruction of plantor animal materials using high-temperaturecombustion ignited <strong>and</strong> burned by auxiliaryfuel such as wood or propane.The objectives of thermal destruction areto convert dead animals or plants into inertgases <strong>and</strong> sterile ash <strong>and</strong> to deactivate pathogens.Some thermal methods can deactivatetransmissible spongiform encephalopathyviruses, which require exposure to very hightemperatures (a minimum of 1,560 °F, or850 °C; preferred temperature: 1,830 °F, or1,000 °C) for at least 15 minutes (Brown etal., “Infectivity Studies of Both Ash <strong>and</strong> AirEmissions from Simulated Incineration ofScrapie-<strong>Contaminated</strong> Tissues,” EnvironmentalScience & Technology, 2004).SummaryFour methods of thermal destruction areused to dispose of infected plants <strong>and</strong>/or animals:• Fixed-facility incineration, in whichmaterials are burned completely <strong>and</strong>reduced to ash at an established facility.Usually fueled by diesel, natural gas,or propane, the incineration is whollycontained <strong>and</strong> usually highly controlled.• Air-curtain burning, in which a fanforces air through a manifold into ametal refractory box or burn pit, wherethe contaminated materials are burnedwith wood <strong>and</strong> diesel fuel. The processincreases the temperature <strong>and</strong> speeds theincineration of the materials.• Open-air burning, in which contaminatedmaterials are burned in open fields77

Thermalon piles of organic materials without theassistance of incineration equipment.The piles are made of materials such aswood or hay bales.• <strong>Field</strong> burning, in which contaminatedplant materials, such as field crops, areburned over large areas. Because ofregulatory statutes, field burning shouldbe considered only under emergencysituations <strong>and</strong> with appropriate regulatoryapprovals.SummaryTo select a feasible method, considerlogistics <strong>and</strong> the type of biomaterials involved(Table 1). The least desirable thermal methodfor carcasses is open-air burning; it should beavoided, primarily because its combustion isinefficient.Compared to the fixed-facility incineration<strong>and</strong> air-curtain burning methods, openairburning poses greater environmental <strong>and</strong>safety hazards.78

Table 1. Methods considerations for thermal destruction.ConsiderationFixed-facility Air-curtain burning Open-air burning <strong>Field</strong> burningincinerationApplication <strong>Animal</strong>s <strong>Animal</strong>s <strong>Animal</strong>s/plants <strong>Plant</strong>sTransportation concerns Yes Yes Yes NoAgents inactivated All Not suitable for TSE 4 Not suitable for TSE 4 All field crop diseasesDisposal capacity 1 Small Large Small Small to large (acreage)Potential forLow Medium High Highenvironmental impactRegulatory restrictions 1 Low Medium High HighCost 2 High 3 Medium Low LowAvailability of resources Low Medium High HighProcedure speed Medium High Low High1<strong>Animal</strong> carcasses (tons): Small = < 100 tons; Medium = 100–299 tons; High = 300+ tons2Cost estimate (per ton): Low = < $200; Medium = $200–800; High = $800+ (Cut-off points may vary, depending on factors suchas carcass load, affected animals, transportation, disposal facility, <strong>and</strong> security level.)3Fixed-facility incineration could be a low-cost option, given the low disposal load.4TSE = transmissible spongiform encephalopathy7979

ThermalDescriptionFixed-facility incinerator: DescriptionIn fixed-facility incineration, materials areburned completely <strong>and</strong> reduced to ash at anestablished facility. The aim of fixed-facilityincineration is to completely burn <strong>and</strong> volatilizecarcasses <strong>and</strong> plants <strong>and</strong> convert them intoinert ash.A fixed-facility incinerator is equippedwith an afterburner that burns the remainingvolatile materials exiting the combustionchamber (Fig. 1). It produces ash that is lessthan 5 percent of the carcass weight (Table 2).Fixed-facility incineration is the preferred<strong>and</strong> approved option for destroying carcassesinfected with transmissible spongiform encephalopathy.It maintains a combustion temperatureof a minimum of 1,560 °F (850 °C)or a preferred temperature of 1,830 °F (1,000°C) for more than 15 minutes. The resultingash is free of pathogens.Typically fueled by diesel, natural gas, orpropane, a controlled fixed-facility incineratorhas a more evenly distributed combustion temperature<strong>and</strong> burns carcasses more effectively<strong>and</strong> completely than does air-curtain burning.Many fixed-facility incineration units inthe United States have a limited throughputcapacity (Table 2) <strong>and</strong> generally hold small ormedium-size carcasses such as poultry carcasseswith lower moisture content <strong>and</strong> swinecarcasses with higher fat content. They generallydo not hold cattle carcasses with highmoisture content (about 70 percent).Grain commodities that are contaminatedwith high levels of mycotoxin, such as aflatoxinsor fumonisins, may be destroyed byfixed-facility incineration, but cost (for facili-80

Figure 1. A fixed-facility incinerator (left) <strong>and</strong> ash from carcass combustion in a fixedfacilityincinerator (right). (Courtesy of FC Industries, Inc. Kansas City, MO)8181

ThermalDescriptionties, transportation, <strong>and</strong> labor) is a limitingfactor. L<strong>and</strong>filling is considered the best practicefor disposing of mycotoxin-contaminatedgrain.Air-curtain burning: DescriptionAir-curtain burning introduces a high volumeof airflow through a manifold to acceleratethe combustion of carcasses at a highertemperature <strong>and</strong> in less time than does openairburning.An air-curtain burner with a centrifugalfan generates airflows, providing an air curtainacross the upper portion of a trench or arefractory box that can withst<strong>and</strong> high temperatures(Fig. 2).Air-curtain burning has a higher throughputcapacity than does fixed-facility incineration,<strong>and</strong> it generates less ash than does openairburning because of its higher combustiontemperatures. Thus, this option may be moresuitable for disposing of massive amounts ofanimal carcasses than is fixed-facility incinerationor open-air burning.A carefully operated air-curtain burner ishotter, cleaner, faster (up to six times), <strong>and</strong>more efficient (in fuel <strong>and</strong> labor) than is openairburning.An air-curtain burning using a refractorybox burns cleaner <strong>and</strong> produces less carbonmonoxide <strong>and</strong> emissions than does air-curtainburning with trenches.The carcass-burning capacity of an aircurtainburner will decrease if the trench/pitbecomes narrower or wider than the dimensionsspecified in Table 2.82

Table 2. The dimensions, burning throughput capacities, <strong>and</strong> field requirements of fixedfacilityincineration <strong>and</strong> air-curtain burning systems.Option Size ThroughputcapacityFixed-facilityincineratorAir-curtainburningTop load opening a :6 x 9 ftTrench burning b :Depth = 8 ftWidth = 10–15 ftSolidfuel/1,000lb carcassweight dLiquidfuel/1,000lb carcassweight dCO glb/hrNMH glb/hrTSP glb/hrNitrogenoxides g asNO 2lb/hrSO 2glb/hr110–500lb/h c –– 60 gal e 0.5 0.05 1.8 2.73 2.824-6 T/h 1,000– 2 gal f N/A h N/A h N/A h N/A h N/A h2,000 lbaApproximate dimensions of large animal incinerators with a single batch load capacity of more than 5,000 lb (such as theTherm-Tec Model made by FC Industries)bTrench length depends on the size needed <strong>and</strong> the number of animal carcasses to be incinerated.cAvailable capacities in the United States (FC Industries, 2006)dAssuming a carcass density of 62.4 lb/ft 3 , the volume of a 1,000-lb carcass is 16 ft 3 .eUse only virgin fuel (such as propane).fUse only for initial ignition of carcasses.gCO = carbon monoxide; NMH = non-methane hydrocarbons; TSP = total suspended particulates; <strong>and</strong> SO 2= sulfur dioxide.(Obtained from New Jersey Department of Environmental Quality.) The particulate matter emissions from fixed-facilityincineration must not exceed 1 lb/h; otherwise, permits from air-quality regulatory agencies are required. To check particulatematter emissions, government-authorized contractors use sensors to measure the stack emission of carcass incineration after thefirst operation of a newly installed fixed-facility incineration system. These contractors will retest if there are any complaints fromneighbors about the emissions of incineration facilities.hNot available8383

ThermalDescriptionFigure 2. An air-curtain burner with a refractory fire box (left) <strong>and</strong> a trench (right).(Courtesy of Air-burners, LLC, Palm City, FL)84

Open-air burning: DescriptionIn the open-air burning method, carcassesare burned in open fields <strong>and</strong> on combustibleheaps (pyres) of materials without the assistanceof incineration equipment. Open-airburning of carcasses occurs on fire beds builtwith organic materials such as hay bales <strong>and</strong>wood, which allow for sufficient air to enterunderneath the bed (Fig. 3).This thermal destruction method is the optionof last resort, as it has significant regulatorylimits, high environmental impacts, <strong>and</strong>very low public acceptance. It is also inappropriatefor massive carcass disposal <strong>and</strong> shouldbe performed only in emergencies when thereare no other options.Open-air burning is subject to State <strong>and</strong>local regulatory approvals.When winds are calm, most of the carcasseswill burn within 48 hours. Compared tofixed-facility incineration or air-curtain burningoperations, open-air burning yields moreairborne ash emissions. Open-air burningrequires much more fuel than does air-curtainburning <strong>and</strong> therefore will yield more ashfrom the burned coals, timber, <strong>and</strong> straw.Because of fire <strong>and</strong> safety hazards, do notconduct open-air burning of carcasses duringwindy conditions.8585

ThermalSummaryFigure 3. Open-air burning of carcasses placed on a pit/trench(Courtesy of Scudamore et al., 2002)86

<strong>Field</strong> burning: Description<strong>Field</strong> burning can be used to destroycontaminated plant materials that are coveringlarge areas, such as annual field crops.Because of regulatory statutes such as theClean Air Act <strong>and</strong> state burn bans, field burningshould be considered only under emergencysituations <strong>and</strong> with appropriate regulatoryapprovals.Also, consider the possibility of spreadingairborne pathogens during a field-burning(flaming) procedure. For instance, fungalpathogens, which can be easily dispersed byair currents or winds, may actually spreadfarther during the burning process.In emergency situations, thermal destructionmethods can be used on site for plantscontaminated with bacterial <strong>and</strong> viral diseasesif the regulatory issues have been resolved.8787

Regulatory SynopsisThermalCoordination <strong>and</strong> jurisdictional considerationsThe decision on the location of the burningactivity should be made jointly by themembers of the incident comm<strong>and</strong> structureestablished by local <strong>and</strong> State authorities.Local authorities should have an intercountymemor<strong>and</strong>um of underst<strong>and</strong>ing inplace so that carcass overflow may be easilytransported to nearby counties for burning.Conduct burning only with explicit approvalby the institutions <strong>and</strong> agencies competentto make decisions about protecting theintegrity of the environment.Open-air burning is subject to local <strong>and</strong>State regulatory approvals.Pollution <strong>and</strong> other property damage considerationsAlthough governmental entities are accordedwide discretion in making decisions aboutburning carcasses to protect public health, theyare subject to nuisance actions if the properprecautions are not taken.The smoke <strong>and</strong> chemicals that result fromopen-pit burning could trigger nuisance or otherkinds of lawsuits. Sovereign immunity—the doctrinethat the government is immune from civilor criminal lawsuits—may not be a defense.As lawsuits could be prompted by injuryto people or damage to property because ofenvironmental pollution, the decision on thedisposal of ash waste must be made jointlyby the appropriate technical group within incidentcomm<strong>and</strong> structure.88

PlanningPlanning considerationsFor all thermal options, consult with theappropriate state regulatory agencies for airquality<strong>and</strong> solid-waste disposal on potentialsites before temporary carcass storage or ashdisposal.Inform the local authorities, includingfirefighting officials, about the planned thermaldestruction. Secure ample fire retardant,equipment, personnel, <strong>and</strong> gear. Provide theappropriate cleaning, disinfection, <strong>and</strong> personalprotective gear.Coordinate with the local utility companyto provide electricity (for example, drop servicefrom power lines for different electricalequipment), <strong>and</strong> secure batteries <strong>and</strong> generatorsfor remote sites.Participate in real-life thermal destructionexercises of carcass disposal. For example,Thermalcontact the fixed-facility incineration operatingunits <strong>and</strong> air-curtain burning manufacturersor contractors to prepare for an animalcatastrophic event (Table 3).Enough trained personnel must be providedfor continual operation <strong>and</strong> maintenance(24 hours a day), as well as ample drinkingwater, housing, <strong>and</strong> meals for workers. Trainingshould include logistical expertise, leadership,<strong>and</strong> managerial skills, <strong>and</strong> health <strong>and</strong>safety precautions needed for thermal destructionof carcass <strong>and</strong> plant residues.Equipment <strong>and</strong> spare parts must be availablefor:• The excavation of trenches/pits in aircurtainburning <strong>and</strong> open-air burningsystems• Carcass loading <strong>and</strong> unloading89

Planning• Ash disposal• Firefighting• Cleaning <strong>and</strong> disinfection• Emergency communication systemsTo enhance the safety of workers in <strong>and</strong>around the equipment, consider providingmechanical loading platforms, conveyors, <strong>and</strong>other equipment. Also consider the predominantwind directions when choosing sites forcontrol rooms <strong>and</strong> worker rest areas.Table 3 lists information on some of themanufacturers, operators, <strong>and</strong> contractorsof fixed-facility incineration <strong>and</strong> air-curtainburning systems.Make a spill response plan, <strong>and</strong> providefor equipment <strong>and</strong> secondary containment foron-site fuel storage.Flashers or signs attached to fences <strong>and</strong> barrierswill be needed to alert approaching travelersof the impending traffic-control points.ThermalConsider important issues related to h<strong>and</strong>ling,storage, <strong>and</strong> conveyance of carcasses tothe incineration or burning site as described inthe “General Considerations” chapter of thisguide.For large numbers of animal carcasses(those with a cumulative weight of more than1 million pounds), conduct the thermal destructionoperations at a distance of 2 miles (3kilometers) from residential buildings, roads,<strong>and</strong> utilities (wires/lines). Air-curtain burning<strong>and</strong> open-air burning operations should alsobe conducted 2 miles from public, religious,historical, <strong>and</strong> archaeological areas.If possible, consider establishing the samedistance from crop fields <strong>and</strong> wildlife. Thiswill protect the public from smoke inhalation<strong>and</strong> excessive heat <strong>and</strong> prevent fire damage toproperty, plants, <strong>and</strong> wildlife.90

Table 3. Contractors <strong>and</strong> operating companies for fixed-facility incineration<strong>and</strong> air-curtain burning systems.Company Nature <strong>and</strong> capacity of work Contact informationFC IndustriesShen<strong>and</strong>oahManufacturing Co., Inc.Air Burners LLCMcPherson SystemsCrowder Excavating, Inc.Phillips <strong>and</strong> Jordan, Inc.Manufactuer of fixed-facilityincinerators, up to 500 lb/hrper unitManufacturer of fixed-facilityincinerators, less than 100 lb/hrper unitManufacturer of air-curtainburners, up to 4 t/hr per unitManufacturer of air-curtainburners, less than 4 t/hrContractor of air-curtain burners,up to 10 t/hrContractor of air-curtain burners,up to 10 t/hr13508 Oak StreetKansas City, MO 64145fcindustries@cysource.com919 Cottontail TrailCrawford, VA 22841www.firelakemfg.com4390 Cargo WayPalm City, FL 34990100 Springhill Church RoadTifton, GA 31794www.mcphersys.com901 Geddie RoadTallahassee, FL 32304P.O. Drawer 604, 191 P&J RoadRobbinsville, NC 28771www.p<strong>and</strong>j.comThis is not an exhaustive list. No endorsement of companies or individuals or their services mentioned isintended, nor is criticism of similar companies implied.9191

PlanningDo not:• Burn carcasses with explosive materials,especially gasoline in fixed-facilityincineration, air-curtain burning, <strong>and</strong>open-air burning operations. The recommendedaccelerants include propane,waste oil, furnace oil, <strong>and</strong> diesel fuel.• Burn carcasses with tires, rubber, plastics,or similar materials because theresulting emissions contain significantamounts of pollutants of concern thatcould affect human health <strong>and</strong> the environment.• Allow personnel to approach the carcassburningsite from downwind withoutproper personal protective equipment.Make arrangements for the disposal ofash obtained from permitted fixed-facilityThermalincineration plants for thermal destruction ofTSE-infected carcasses in licensed l<strong>and</strong>fills(approved by the U.S. Environmental ProtectionAgency, 2004).The ash of non-infected carcasses (obtainedfrom fixed-facility incineration, aircurtainburning, <strong>and</strong> open-air burning options)can be applied to agricultural l<strong>and</strong>s.If ash is l<strong>and</strong>-applied, allow an area of ½acre per:• 60,000 broilers• 30,000 layers• 100 adult hogs (average weight of 375pounds)• 75 large or heavy cattle (average weightof 500 pounds)Plan to restore the thermal destruction siteto its original condition.92

Planning for fixed-facility incinerationObtain the required licenses from thestate government or regulatory agencies tobuild <strong>and</strong> operate a fixed-facility incinerationsystem. For example, in New Jersey, the Departmentof Environmental Protection issuespermits for preconstruction <strong>and</strong> the certificateof operation for fixed-facility incinerationsystems. In Texas, regulations that controlparticulate emissions <strong>and</strong> air quality of incineratorsused on poultry farms must meet thePlanning for air-curtain burningAssess the availability, location, <strong>and</strong> costsrelated to air-curtain burning. Although aircurtainburning units are mobile, the locationof a disaster may limit availability or access.specifications of the Texas Commission onEnvironmental Quality.<strong>Animal</strong> carcasses must be fed through adoor into the refractory bottom of the mainincineration chamber. If the fixed-facilityincineration’s average capacity becomesoverburdened, the carcasses must be storedin a refrigerated room, transport vehicle, orfreezer.Plan to provide an electrical generator (includingdiesel fuel) <strong>and</strong> lighting equipment toilluminate the thermal destruction site <strong>and</strong> identify“authorized personnel only” work areas.9393

PlanningThermalPlanning for open-air burningA fire bed will need to be built perpendicularto the prevailing wind to minimizethe amount of sparks, soot, <strong>and</strong> objectionableodors blowing toward buildings or acrosspublic roads.Plan to use mechanical chains <strong>and</strong> liftingequipment (such as front-end loaders) toaccomplish all the loading, spreading, <strong>and</strong>h<strong>and</strong>ling of solid fuels <strong>and</strong> carcasses.Considering one adult bovine carcass tobe equal to five finishing pigs or five adultsheep, the amount of solid <strong>and</strong> liquid fuelsneeded for each bovine carcass (averageweight of 1,000 pounds) is:• Three bales of straw or hay• Three pieces of untreated heavy lumber(about 8 feet long by 1 square footin cross section). Railroad ties, bridgelumber, <strong>and</strong> smaller wood such as fenceor cordwood are useful too.• 50 pounds of kindling wood. Sourcesinclude wrecking companies, farmwoodpiles, <strong>and</strong> sawmill slab piles.• 100 pounds of coal pieces, with 6 to 8inches in diameter• 1 gallon of liquid fuel such as waste oil,furnace oil, or diesel fuel. Do not usegasoline as a fuel for carcass burning.Be careful when using flammable <strong>and</strong>hazardous liquid fuel.Plan to restore the open-burning site to itsoriginal condition.94

Planning for field burning<strong>Field</strong> burning is considered an economicalmethod for disposing of contaminated plantmaterials unless fuel costs rise too high.Perennial field crops such as fruit trees<strong>and</strong> lumber may be destroyed on-site if theproper open-air burning procedures are followed.Address site-safety <strong>and</strong> air-quality issuesbefore beginning destruction procedures.One caution with these burning methods isto avoid lumbers that are treated with chemicalssuch as chromated copper arsenate. Theselumbers are typically treated as special waste<strong>and</strong> must be disposed in accordance with local<strong>and</strong> State regulations. In general, the lumberscan be buried at approved l<strong>and</strong>fills but cannotbe incinerated as are other plant materials.Nursery greenhouse plant materials maybe burned at designated burning locations.However, if a fixed facility is used, the cost ofharvesting <strong>and</strong> transporting the crop materialsshould be considered.For some crop pathogens, field burningmay have undesirable effects <strong>and</strong> increase theseverity of the disease. Consult with a plantdisease specialist before conducting a fieldburningoperation.9595

ProceduresThermalProcedure for fixed-facility incinerationFeed the animal carcasses through amanually or hydraulically activated door intothe refractory bottom of the main incinerationchamber. If the fixed-facility incinerator’s averagecapacity becomes overburdened, storethe carcasses in a refrigerated room, transportvehicle, or freezer.Preset the burning time <strong>and</strong> temperaturemanually or automatically (using programmabledigital controls).Adjust the pressure of the air blowers tocreate turbulence <strong>and</strong> to distribute the combustionair to the afterburner (secondarychamber) to reach <strong>and</strong> maintain temperaturesat a minimum of 1,560 °F (or 850 °C), or apreferred temperature above 1,830 °F (about1,000 °C). Monitor the temperature using adigital temperature sensor.The amount of combustion time requireddepends on the carcass load for each batch<strong>and</strong> the capacity of the fixed-facility incinerationsystem. For example, it may take 10hours to incinerate 5,000 pounds of carcassesin a fixed-facility incineration unit with athroughput of 500 pounds per hour.Reload the system with carcasses aftercombustion of the first batch is completed.After all the carcasses have been incinerated,shut off the combustion system <strong>and</strong> allowit to cool down for 10 hours to enable theash to be removed <strong>and</strong> h<strong>and</strong>led safely.96

Procedure for air-curtain burningLocate the air-curtain burning unit in anarea that is easily accessible to heavy vehicleshauling carcasses, <strong>and</strong> equipment.Consult with the USDA Natural ResourcesConservation Service <strong>and</strong> evaluate the site forthe depth to the water table <strong>and</strong> proper soilconditions.Build the trenches according to the dimensionsin Table 2. This approach accommodatesmore carcasses than does burning in refractoryboxes because the ash can be buried in thetrenches after the carcass combustion is completed.Refractory boxes should be used on siteswith a high water table (less than 2 feet fromthe bottom of a planned trench) or on rockysoil <strong>and</strong> where trenches would be difficult orcostly to build.Monitor the wind direction before <strong>and</strong>during the burning operations, <strong>and</strong> keep theworkers out of the path of the flame.Use solid fuels such as straw, hay, coal,kindling wood, <strong>and</strong> untreated lumber.For proper combustion, provide an appropriatesolid fuel-to-carcass weight ratio rangingfrom 1:1 to 2:1. The fuel-to-carcass ratiois determined by the moisture in the woodor other organic sources (such as hay, grainstalks, <strong>and</strong> straw) <strong>and</strong> the fat <strong>and</strong> moisture contentof the carcasses. For example, the finishedhogs have more fat <strong>and</strong> less water than do steercarcasses.To reduce air pollution, h<strong>and</strong>le the ash inthe refractory boxes carefully <strong>and</strong> dispose of itat a burial or l<strong>and</strong> application site that has beenapproved by the appropriate regulatory agency.9797

ProceduresThermalProcedure for open-air burningStake out <strong>and</strong> fence the selected burningsite for the fire-bed construction.Allow a fire-bed length of 3 feet for eachadult cattle carcass, five swine carcasses, orfive sheep carcasses.Lay three rectangular rows of straw orhay bales lengthwise along the line of the firebed (Fig. 4). These rows should be 12 inchesapart; each bale should be separated by a 12-inch gap within the row.Fill the spaces between the rows <strong>and</strong> baleswith loose straw to provide natural air flow.Place large pieces of lumber lengthwiseon top of each row. Distribute the large <strong>and</strong>medium-sized pieces of lumber across the firebed, leaving 6 to 12 inches of space betweenthem. Place small kindling wood on the firebed, <strong>and</strong> cover it with loose straw.Spread 6- to 8-inch-diameter coal evenlyat the rate of 500 pounds per square yard, orother liquid fuel such as diesel or furnace oil,over the wood mixture to make a level bed.Lay the carcasses on the fire bed, positionedon their backs with their feet in the air<strong>and</strong> alternately head to tail. Place the carcassesof goats, sheep, or swine on top of the bovinecarcasses <strong>and</strong> burn them without additionalfuel at the rate of two animals per bovine carcass.Place loose straw over the carcasses <strong>and</strong>fill all the spaces between the carcasses.Spray the liquid fuel over the fire bed witha pump, or use sprinkling cans or buckets.Soak rags or similar materials in keroseneoil or waste oil, <strong>and</strong> place them every 30 feetalong the fire bed for a better <strong>and</strong> more harmonizedignition.98

Before igniting the fire bed, make surethat all people, equipment, <strong>and</strong> supplies are atleast 25 feet from the burning pile. Have firefightingequipment ready in case the equipment,buildings, or grass ignites.Use front-end loaders to stir the burningpile occasionally. Quickly replace any carcasspieces that drop off the pile, <strong>and</strong> add morefuel if needed. Be careful! Do not douse openflames with flammable liquids.Bury the ash after all the carcasses havebeen burned completely <strong>and</strong> the fire has beenextinguished thoroughly.9999

ProceduresThermalFigure 4. Side view <strong>and</strong> cross section of carcass open-air burning setup.Side viewof the fire bedHay bales(3 ft length)Spaces filled with loose straw(1 ft length)Illustrations are not to scale.CarcassLoose strawHay balesCoalFlamesTimberKindling wood<strong>and</strong> loose strawCross sectionof the fire bed100

Procedure for field burningCheck with the local authorities on thehealth, safety, <strong>and</strong> environmental restrictionsfor field burning. <strong>Field</strong> burning is recommendedonly for emergencies.Before igniting the fire, verify that thecrops (or crop residues) are dry. Annual fieldcrop residues may need 3 to 10 days of dryingtime. For drying perennial field crops, 3weeks (for small branches) to 6 weeks (forlarge branches <strong>and</strong> stumps) is recommended.Consult with local authorities on safetymeasures <strong>and</strong> specific burn hours (if any). Ensurethat the burning activities are supervised<strong>and</strong> that the burning area has been fire-guardedadequately.Propane- or oil-fueled flamers, whichdo not produce black smoke, can be used toignite <strong>and</strong> destroy contaminated plant materials.<strong>Plant</strong> materials are a solid fuel containingvarying amounts of minerals <strong>and</strong> moisture.Light a test fire. Observe whether thedried plant materials burn, <strong>and</strong> note the directionof the smoke. Terminate the operationif the plant materials are too damp or if thesmoke is blowing toward populated areas.If possible for the full-scale fire, light thefire on the downwind side of the field—it willburn more slowly but more thoroughly.For tree branches <strong>and</strong> stumps, stack thestarter pile tightly, but make sure there isenough air circulation. Ignite the fire with apropane torch or other commercial lightingdevice. When the starter pile is fully engulfed,continue adding dried plant materials.101101

SafetyThermalTable 4. Personal protective equipment guidelines for thermal destruction operations.Natureof workFixed-facilityincinerationworkersdirectlyh<strong>and</strong>lingcontaminatedmaterialAir-curtainburningworkersdirectlyh<strong>and</strong>lingcontaminatedmateriala, b, cMask/respirator ProtectiveZoonoticagentDisposableparticulaterespirator(N95, N99, orN100); half orfull facepieceSame as forfixed-facilityincinerationNon-zoonoticagentNonerecommendedunless for foot<strong>and</strong>-mouthdiseaseSame as forfixed-facilityincinerationclothing aLiquidimpermeablesuit orovergarment(such as anapron)Liquidimpermeablesuit orovergarment(such as anapron)Eye/hearing Gloves a Head/footprotection a, c protectionSame as foropen-airburningSame as foropen-airburningSame as foropen-airburningSame as foropen-airburningSame as foropen-airburningSame as foropen-airburning(Continued on next page)102

Table 4. (Continued)Natureof worka, b, cMask/respirator Protectiveclothing aEye/hearing Gloves a Head/footprotection a, c protectionZoonoticagentNon-zoonoticagentOpen-airburningDisposableparticulaterespirator(N95, N99,or N100);half or fullfacepiece (fordescription,see Safetysection of thisguide)Nonerecommendedunlessnuisancedusts/ashimpede workImpermeableto liquids;considerfire-retardantovergarmentfor thoseworkingaround openflame; selectbased on heatsituationEyes: Fullfacepiecerespiratoror indirectlyvented goggles;contact lensesshould not beworn undergoggles orsafety glasses;considerGloves: Heavyduty(15–18mil) chemicalresistant glovesthat can bedisinfected ordisposed of;consider 10–12mil nitrile glovesworn underleather gloves,Feet: Forworkersh<strong>and</strong>lingcarcasses, steeltoe/steel shankwaterproofboots; forothers, steeltoedwork shoesor bootsHead: Hard hatprescriptionsafety gogglesHearing:Considerdisposableearplugs ifnecessarydepending ontaskaSee www.safetyequipment.org for a list of vendors from OSHAbFor information on a full respiratory protection program, see www.osha/gov/SLTC/respiratoryprotection/indexcRegulations governing use of personal protective equipment in hazardous waste operations can be found at 29 CFR 1910.134<strong>and</strong> 29 CFR 1910.156 <strong>and</strong> are summarized in the Safety section of this guide.103103

SafetyDiseases of concernViruses <strong>and</strong> non-spore-forming bacteria:Viruses <strong>and</strong> non-spore-forming bacteriaare temperature susceptible. However,some viruses such as foot-<strong>and</strong>-mouth disease(FMD) are easily spread by piggybacking inthe respiratory tract of humans. Take precautionsto prevent inhalation of these airbornepathogens. Use appropriate personal protectiveequipment.Although open-air burning <strong>and</strong> air-curtainburning are suitable for destroying viruses <strong>and</strong>non-spore-forming bacteria, the best methodfor controlling the spread of disease is fixedfacilityincineration.The diseases for which thermal methodsare appropriate include African swine fever,highly pathogenic avian influenza, contagiousbovine pleuropneumonia, brucellosisThermal(B. melitensis, B. abortus, <strong>and</strong> B. suis), FMD,gl<strong>and</strong>ers, Japanese encephalitis, Q fever, RiftValley fever, rinderpest, classical swine fever,tularemia, <strong>and</strong> vesicular stomatitis.Spore-forming bacteria: Although sporeformingbacteria are temperature susceptible,they must be incinerated thoroughly. If notdestroyed, they will persist in the environmentfor long periods.If it is not possible to incinerate the carcassesimmediately, the carcasses must remainintact to prevent the spread of spores into theenvironment.Fixed-facility incineration is the bestmethod for destroying carcasses contaminatedwith a spore-forming bacteria.Diseases of concern include anthrax.Prions: Because prions are temperature104

Site safetyHeat stress is a major consideration duringhazardous waste disposal operations <strong>and</strong>an even greater consideration when usingthermal destruction methods. See the heatexposure guidelines in the “General Considerations”chapter of this guide.resistant, destroying them requires that they beexposed to extremely high temperatures (minimumof 1,560 °F, or 850 °C, or a preferredtemperature of about 1,830 °F, or 1,000 °C)for at least 15 minutes. Lower temperatureswill generate ash, but the prions will persistin the ash until the process exceeds 800 °C. Ifnot inactivated by heat, the prions may persistin ash or soil for a considerable period.The best thermal method for destructionof prion-infected animal carcasses is fixed-facilityburning. Open-air burning <strong>and</strong> air-curtainburning may not provide the temperaturesrequired to destroy these diseases.Although the ash from burning carcasses,particularly those infected with conventional microorganisms,may be suitable for later uses suchas l<strong>and</strong> application, its use may be precluded bypublic opposition to the use of ash from carcassesinfected with some pathogens, particularlytransmissible spongiform encephalopathy.Diseases include bovine spongiformencephalopathy, chronic wasting disease, <strong>and</strong>scrapie.Set the work schedule according to workerneeds. A worker with a core temperature of100.4 °F is considered at a heat stress level.To prevent dehydration, allow the workers todrink water at liberty.The U.S. Occupational Safety <strong>and</strong> Health105105

SafetyAdministration suggests establishing:• A training program informing employeesabout heat stress• A screening program to identify workerhealth conditions before beginning anyburning• Procedural programs guiding the workersin case of a heat-related emergencyBecause all of these thermal methods posesignificant fire hazards, workers must wearappropriate personal protective equipmentwhile inside the perimeter (Table 4).Avoid inhaling the toxic smoke constituentsfrom petroleum <strong>and</strong> coal as much as possible,<strong>and</strong> do not allow it to contact the skin.Monitor the wind direction <strong>and</strong> speed, <strong>and</strong>Thermalbe prepared to move unprotected personnel.For protection while moving <strong>and</strong> burningcarcasses during fixed-facility incineration,air-curtain burning, <strong>and</strong> open-air burningoperations, workers should wear half- orfull-facepiece air-purifying respirators withappropriate filter cartridges. Chemical protectiveclothing is especially important duringmovement of carcasses.During the actual burning process, workersshould wear clothes suitable for high-heatsituations, including flame-retardant coats,pants, steel-toe rubber boots, gloves, <strong>and</strong> helmetswith facepieces. Although it is more controlledthan is open-air burning, fixed-facilityincineration does pose a fire hazard.106

BiosecurityBest practices <strong>and</strong> guidelines for biosecurityare found in the Safety <strong>and</strong> Biosecuritysection of the “General Considerations” chapterof this guide.Decontaminating heat-resistant clothingis difficult. As such, firefighter “turnout”gear should not be used by personnel directlyh<strong>and</strong>ling contaminated material unless suchThermalclothing is expendable (that is, it can be destroyed<strong>and</strong> will not be reused) or can be usedmultiple times onsite before final destruction.In many jurisdictions, the ash could beconsidered contaminated material <strong>and</strong> be subjectto various regulations. Consult with Stateagriculture <strong>and</strong> environmental regulatoryagencies before disposing of ash by burial.107

Environmental ImpactsThermalGroundwater <strong>and</strong> soil pollutionAfter the thermal destruction of diseasedcarcasses, most of the waste produced will bein the form of ash. If the destruction methodsare conducted thoroughly <strong>and</strong> as described inthis guide, the resultant ash would be consideredsafe for burial or further use.Carcasses affected by transmissiblespongiform encephalopathy that are notburned for at least 15 minutes at about aminimum of 1,560 °F (850 °C) or a preferredtemperature of 1,830 °F (1,000 °C) may continueto pose a potential health risk to people,animals, <strong>and</strong> the environment. Even if thecarcasses are burned thoroughly, public concernmay be great enough that the ash shouldbe disposed of as contaminated waste <strong>and</strong> notcomposted or buried at unregulated sites.Toxicants such as dioxins, polychlorinatedbiphenyls (PCBs), <strong>and</strong> polynuclear aromatichydrocarbons (PAHs) are often generated asbyproducts of burning pyres <strong>and</strong> fuel. Thesetoxicants can threaten the soil <strong>and</strong> groundwater.Even relatively low concentrations ofthese materials left in the soil may result insome States requiring further cleanup of theburn site.These risks are heightened mainly byopen-air burning techniques in pits. In thepast, measures were taken to ensure that as littlecontamination as possible seeped into thesoil. These precautions have kept the soil <strong>and</strong>groundwater chemical levels at a minimum.108

Air pollutionFixed-facility incineration should be thefirst choice during an outbreak <strong>and</strong> at the endwhen the small number of carcasses makesthe other methods uneconomical or otherwiseunsuitable. Fixed-facility incineration significantlyreduces the amount of air pollution ina small area. Most hydrocarbons <strong>and</strong> otherairborne toxicants are reduced by this method.Like fixed-facility incineration, air-curtainburning produces smaller plumes of smokethan do the other thermal methods. Comparedto open-air burning, air-curtain burning hashigher combustion efficiencies <strong>and</strong> producesless carbon monoxide.Of the thermal methods in this guide, theone generating the most air pollution is openairburning. Volatile chemicals <strong>and</strong> particulatematter in the form of smoke are released intothe air when burning fuel, wood, coal, <strong>and</strong>animal <strong>and</strong> plant materials. In quantities generatedby open-air burning, these chemicalsmay present a health hazard to personnel notwearing appropriate respirators (Table 4) nearthe open pit.109109

Environmental ImpactsThermalAdditional information: Waste producedAll of these burning methods producesignificant amounts of benign ash waste. Thisash may be used as fertilizer because it doesnot usually attract pests if it is burned thoroughly.As noted, carcass materials containingresidues potentially contaminated with transmissiblespongiform encephalopathy shouldbe disposed of as contaminated waste accordingto State regulations.110

CostThermal destruction costsThe cost components relating to thermaldestruction follow the general specificationsin the overall direct/indirect economic costsection. Figure 5 demonstrates the main costcomponents.For specific indirect cost items, see the“General Considerations” chapter of thisguide.ThermalFigure 5. Components of direct <strong>and</strong> indirectcosts of thermal destruction methods.LaborInterest rateEnvironmentalimpactsFuelDepreciationOthersElectricityMaintenance<strong>and</strong> repairTransportationEnvironmentalpermitting fee111

CostDirect costsThermalThe direct fixed cost depends on facilitytype (with or without afterburner) <strong>and</strong> capacity.Table 5 shows the initial investment <strong>and</strong>the corresponding direct annual fixed cost estimatesof thermal destruction with an annualcapacity of 40,000 pounds.Tables 6 <strong>and</strong> 7 list the direct variable costsper carcass <strong>and</strong> per ton for various animals.Table 8 shows the cost of an air-burning projectfor 91,600 pounds of swine.The fixed-facility incineration, air-curtainburning <strong>and</strong> open-air burning methods arenot cost efficient for disposal of contaminatedplants, mainly because of transportation costs.Costs for field burning of plants are for asmall amount of fuel to start the fire <strong>and</strong> forlabor to start <strong>and</strong> control the fire.112

Table 5. Initial investments for incineration with <strong>and</strong> without an afterburner of anannual capacity of 40,000 pounds.With afterburnerInvestment($)Depreciation a($)Maintenance<strong>and</strong> repair(3%)Interest(6%)Annual cost($)Incineration (500 lb/cycle) 3,000.00 300.00 90.00 180.00 570.00Shed <strong>and</strong> base slab 642.00 64.20 19.26 38.52 121.98Afterburner 1,000.00 100.00 30.00 60.00 190.00Total 4,642.00 464.20 139.26 278.52 881.98Without afterburnerInvestment($)Depreciation($)Maintenance<strong>and</strong> repair(3.0%)Interest(6%)Annual Cost($)Incineration (500 lb/cycle) 3,000.00 300.00 90.00 180.00 570.00Shed <strong>and</strong> base slab 642.00 64.20 19.26 38.52 121.98Total 3,642.00 364.20 109.26 218.52 691.98aThe life expectancy of the investment is assumed to be 10 years.113113

CostThermalTable 6. Estimates of direct variable costs per carcass of thermal destruction.Consideration Cattle Calves Weaned hogs PreweanedhogsOthers (sheep,lambs, goats)Labor ($10/hr) $11.36 $4.03 $2.02 $0.09 $1.17Fuel a ($2.40/gal) $31.15 $11.05 $5.52 $0.25 $3.20Electricity ($0.0024/lb) $1.80 $0.64 $0.32 $0.01 $0.18Environmental permitting fee n/a n/a n/a n/a n/aTransportation n/a n/a n/a n/a n/aAverage cost per carcass $44.31 $15.72 $7.86 $0.35 $4.55Source: http://www.ianrpubs.unl.edu/epublic/pages/publicationD.jsp?publicationId=193aBoth propane <strong>and</strong> diesel can be used as fuel. Diesel (propane) needs 1.35 gal (1 gal) per hour <strong>and</strong> each gallon will burn 78 lb(31 lb) of carcasses.114

Table 7. Estimates of direct variablecosts per ton of thermal destruction for cattle,calves, weaned hogs, preweaned hogs, <strong>and</strong>others (sheep, lambs, <strong>and</strong> goats) when themanager has thermal disposal facilities.Consideration CostLabor ($10/hr) $30.30Fuel a ($2.40/gal) $83.08Electricity ($0.0024/lb) $4.80Environmental permitting feeN/A bTransportationN/A bAverage cost per ton $118.18Source: http://www.ianrpubs.unl.edu/epublic/pages/publicationD.jsp?publicationId=193aBoth propane <strong>and</strong> diesel can be used as fuel. Diesel (propane)needs 1.35 gal (1 gal) per hour <strong>and</strong> each gallon will burn 78lb (31 lb) of carcasses.bN/A = not applicableTable 8. Costs of an air-curtain burningproject based on 91,600 pounds of swinecarcasses if the thermal disposal facility isrented. (Courtesy of the National AgriculturalBiosecurity Center Consortium for CarcassDisposal Working Group)ConsiderationCostSite <strong>and</strong> equipment preparation $1,700Site rental (by contract) 650Air-curtain incinerator 7,500Diesel fuel 1 300Protective clothing 2,400Lumber <strong>and</strong> plywood 135Firewood <strong>and</strong> delivery 3,960Truck rental 250<strong>Animal</strong> transportation 4,640Modification of chute/knock box 1,285Miscellaneous supplies 225Total costs $23,045Cost per ton $5031The fuel prices dramatically increase <strong>and</strong>, thus, this costcomponent needs to be considered.115115

CostThermalFigure 6. Formulas to estimate the direct variable cost relating to thermal destruction.If the hourly labor, fuel price <strong>and</strong> electricity prices are $10/hr, $2.4/gallon, <strong>and</strong> $0.0024/lbof animal carcasses, the formulas to estimate the direct variable cost (DVC) are• By carcass:DVC = 44.31Q cattle+ 15.72Q calves+ 7.86Q weaned hogs+ 0.35Q preweaned hogs+ 4.55Q othersWhere Q iis the total mortality of animal category i.• By weight:DVC = 118.18 (W cattle+ W calves+ W weaned hogs+ W preweaned hogs+ W others)Where W iis the total weight in tons of animal category i.(Figure continued on next page)116 116

Figure 6. (Continued)If the hourly labor cost, fuel price <strong>and</strong> electricity price, are C L, C F<strong>and</strong> C Erather than $10/hr,$2.4 gallon <strong>and</strong> $0.0024/lb, formulas to estimate the direct variable cost (DVC) are• By carcass:DVC = (1.1C L+ 13.0C F+ 750.0C E)Q cattle+ (0.4C L+ 4.6C F+ 266.0C E)Q calves+ (0.2C L+ 2.3C F+133.0C E)Q weaned hogs+ (0.01C L+ 0.1C F+ 6.0C E)Q preweaned hogs+ (0.1C L+ 1.3C F+ 77.0C E)Q othersWhere Q iis the total mortality of animal category i.• By weight:TVC = (3.0C L+ 34.6C F+ 200.0C E)(W cattle+ W calves+ W weaned hogs+ W preweaned hogs+ W others)Where W iis the total weight in tons of animal category i.Besides labor, fuel, <strong>and</strong> electricity costs,direct variable disposal costs include transportationcost, which depends mainly on thedistance that the carcasses are moved.117117

BurialDefinition <strong>and</strong> objectivesBurial methods are disposal practicesin which plants <strong>and</strong> dead animals (contaminatedbiomaterials) are placed in earth-filledtrenches or pits. These contaminated biomaterialsare disposed of in a properly selected,enclosed environment <strong>and</strong> may be mixed withsoil <strong>and</strong> solid waste in l<strong>and</strong>fills.In h<strong>and</strong>ling contaminated animals <strong>and</strong>plants, the objectives of burial methods are to:• Provide the conditions that impede thegrowth <strong>and</strong> spread of pathogens from thecontaminated materials <strong>and</strong> limit accessto them by vermin• Convert the contaminated materials intoinert compounds (mainly minerals)Summary• Control nuisance odors• Dispose of <strong>and</strong> degrade the materials sothat they neither pose a health hazard norpollute the air, water, leachate, or soilBurial <strong>and</strong> l<strong>and</strong>filling can be used onlywhere allowed by permits <strong>and</strong> the depths ofthe soil <strong>and</strong> water table.Large amounts of contaminated materialscan be disposed of by trench burial (animals),l<strong>and</strong>filling (animals <strong>and</strong> plants), mass burial(animals), <strong>and</strong> field burial (plants). To select afeasible method, consider the classification ofthe contaminated materials <strong>and</strong> the logistics—cost, location, facilities, <strong>and</strong> environmentalimpact—for h<strong>and</strong>ling them (Table 1).118

Table 1. Methods considerations for the burial of contaminated plants <strong>and</strong> animals.Consideration Trench burial L<strong>and</strong>filling Mass burial <strong>Field</strong> burialApplication <strong>Animal</strong>s <strong>Animal</strong>/plants <strong>Animal</strong>s <strong>Plant</strong>sTransportation concerns No Yes Yes NoPathogens inactivated Viruses <strong>and</strong>Viruses <strong>and</strong>Viruses <strong>and</strong>All field crop diseasesnon-spore-formingbacterianon-spore-formingbacterianon-spore-formingbacteriaDisposal capacity 1 Small to large Small to medium Small to medium Small to large (acreage)Potential forHigh Medium Medium Lowenvironmental impactRegulatory restrictions 2 Medium High High LowCost 3 Low Medium High LowAvailability of resources High Medium Low HighProcedure speed High Medium Low High1<strong>Animal</strong> mortality (tons): Low = < 100 t; Medium = 100–300 t; High = > 300 t2The stringency of restrictions imposed by federal, state <strong>and</strong> local agencies3Cost estimate (per ton): Low = < $200; Medium = $200–800; High = > $800(Cutoff points may vary, depending on such factors as transportation, carcass load, animals affected, disposal facility, <strong>and</strong> level ofsecurity.)119119

BurialTrench burialIn the trench burial method, animal carcassesare placed in unlined trenches or pitsthat are then backfilled with excavated soil.The soil absorbs the leachate <strong>and</strong> microorganisms<strong>and</strong> minimizes feeding by scavengers.Trench burial provides a confined soilenvironment for absorbing carcass fluids <strong>and</strong>preventing heat loss, thus speeding up theanaerobic degradation process at low moisturecontent.This method offers several advantages:• It is logistically simple <strong>and</strong> relativelyeasier than are the other burial options.• The equipment needed for this disposalmethod is widely available at farms <strong>and</strong>feed yards.• Burying the animals on site eliminatesthe need for transporting potentiallySummaryinfectious materials to l<strong>and</strong>fills or massburial sites.However, this method encourages vermin<strong>and</strong> increases the potential for groundwatercontamination. Also, routine poultry carcassesare usually not permitted to be buried on site.Some States, such as Texas, permit the on-siteburial of poultry carcasses in emergencieswhen the mortality rate exceeds 0.3 percent ofthe total on-farm inventory per day.Although the trench burial method needsmuch less area than does mass burial, a limitingfactor is the availability of sites with theappropriate soil <strong>and</strong> hydrologic properties.From an environmental perspective,trench burial is the least preferred burial optionfor carcass disposal because the trenchwalls <strong>and</strong> bottom are not lined with an imper-120

meable barrier, as is required for mass burial<strong>and</strong> l<strong>and</strong>filling.The decomposition time for buried carcassesdepends on the species, carcass size,<strong>and</strong> soil properties (texture, temperature,moisture <strong>and</strong> chemical composition).Another disadvantage of trench burial isthat although the carcass body fluid will drainwithin about 2 months, it can take a long timeto release much of the pollutant load from thecarcass material. Buried carcasses may continueL<strong>and</strong>filling: DescriptionL<strong>and</strong>filling is an excellent option fordisposing of carcasses if the farm operation ororganizations supporting the incident responsehave access to vehicles large enough <strong>and</strong> suitablefor transporting the carcasses quickly <strong>and</strong>biosecurely.The aim of l<strong>and</strong>filling is to deposit theto produce both leachate <strong>and</strong> gas for as long as20 years; they may harbor spore-forming bacteriasuch as Bacillus anthracis for 200 years,as has been seen from old, infected graves.Despite the heat generated from the buriedcarcasses, many bacteria may survive, especiallywhen they are buried in cold climatesor during cold seasons. Summer is a moresuitable time in which to bury dead animalsbecause they decompose faster then <strong>and</strong> thesoil is easier to excavate.dead animals in an engineered, sealed containmentarea between layers of compactedsolid waste <strong>and</strong> impermeable lining materials.The carcasses are taken to a Type I l<strong>and</strong>fill, amodern facility permitted to accept municipalsolid waste, contaminated soil, <strong>and</strong> deadanimals.121121

BurialSummaryThe leachate from the contaminatedcarcasses is collected <strong>and</strong> sprayed <strong>and</strong> recirculatedon the surface of the l<strong>and</strong>fill area.Of the l<strong>and</strong>fill area designated for carcassdisposal, only 30 percent is used for the actualburial of carcasses. The remaining acreage is requiredfor runoff <strong>and</strong> leachate collection, dropoffstations, a buffer area, <strong>and</strong> sites from whichcover soil can be obtained or “borrowed.”The base <strong>and</strong> walls of modern l<strong>and</strong>fillsare built with 2 to 3 feet (0.6 to 0.9 meter) ofcompacted impermeable soil. The soil’s hydraulicconductivity must be less than 0.00034inch per day. The l<strong>and</strong>fill base <strong>and</strong> walls arelined with a thick, flexible membrane that isat least 30 mils (0.76 millimeter) thick. Liningmade of high-density polyethylene must be 60mils (1.52 millimeters) thick.Although adding this lining increases thecost of disposal, it reduces the risk of exposureto the environment <strong>and</strong> reduces futureliabilities.For modern l<strong>and</strong>filling sites, the amountof setup time for carcass disposal is minimalif the disposal arrangements are made inadvance. However, the carcasses may takelonger to degrade at a l<strong>and</strong>fill than in a trenchburial site because the co-fill materials inl<strong>and</strong>fills are less homogenous than the soil intrenches, <strong>and</strong> they absorb moisture inconsistently.In addition to the inconsistent moisturecontents, l<strong>and</strong>fills have widely varying temperatures,which can also slow the biochemicalreactions in the carcasses. These reactionsmay generate l<strong>and</strong>fill gases, includingmethane <strong>and</strong> carbon dioxide as well as traceamounts of hydrogen, hydrogen sulfide, <strong>and</strong>carbon monoxide. If the l<strong>and</strong>fill operations areconducted improperly, these noxious gases122

may be released to the air, <strong>and</strong> leachate <strong>and</strong>gases may migrate to the soil <strong>and</strong> water.Another drawback is that the temperaturesin l<strong>and</strong>fills do not reach high enough toinactivate heat-resistant organisms <strong>and</strong> sporeformingbacteria. Also, modern l<strong>and</strong>fills arenot available in every state.Some l<strong>and</strong>fill sites are owned by municipalities;others are privately owned.Those owned by municipalities may not haveenough capacity for additional waste such ascarcasses. All owners may face political consequencesof accepting the carcasses. SomeMass burialMass burial is used when large numbersof animal carcasses are collected from multipledisaster locations <strong>and</strong> buried at remotedesignated sites that have pre-engineered <strong>and</strong>constructed pits.l<strong>and</strong>fills may not accept carcass materialsbecause of local opposition or fear of diseasetransmission.Long-term requirements <strong>and</strong> costs for thismethod include the maintenance of the l<strong>and</strong>fill’slined surface (cap) to control pollution<strong>and</strong> prevent settling.The st<strong>and</strong>ard operating procedure forl<strong>and</strong>filling animals can be used for disposingof plant materials. Because of the nature ofplant pathogens, those planning plant disposaloperations should focus more on costs <strong>and</strong>logistics issues than on biosafety.Mass burial is appropriate if no licensedl<strong>and</strong>fill in the disaster area accepts carcasses.Generally, the inputs <strong>and</strong> resources needed formass burial sites are in many ways similar tothose of l<strong>and</strong>filling.123123

BurialMass burial is an engineered technologythat requires lead time for proper design<strong>and</strong> construction as well as prior regulatoryapprovals. The pits for mass burial are builtwith sophisticated liners <strong>and</strong> proper drainageto collect the carcass leachate <strong>and</strong> to minimizethe risk of contaminating the groundwater. Althoughthis lined design may make the optionmore costly, it greatly minimizes the risk offuture liabilities <strong>and</strong> harm to the environment.Mass burial may be necessary at theheight of a large outbreak such as during theUnited Kingdom’s incidence of foot-<strong>and</strong>mouthdisease, when the number of diseased,at-risk, or humanely slaughtered animalsoverwhelmed other disposal methods.SummaryIn emergency situations, the mass burialof carcasses is done in shallow (about 3 feet[0.9 meter] deep) trenches. Therefore, massburial requires more l<strong>and</strong> area than doestrench burial. Preconstructed mass burial sitescan reach to 10 feet (about 3 meters) deep.Because the lined walls <strong>and</strong> bottoms ofmass burial pits are sealed, the carcass leachateis not absorbed. Therefore, the leachatecollection system must be engineered properly,with the leachate being conveyed to atreatment facility.Mass burial pits should be located onground that is level or gently sloping (lessthan 5 percent).124

<strong>Field</strong> burial<strong>Field</strong> burial is suitable for disposing ofcontaminated plant materials, particularlyannual field crops. Generally termed tillage orcultivation in field crop production, field burialis used to remove established vegetation <strong>and</strong>to prepare the soil for planting a new crop.The goal of this method of disposal is tobury contaminated plant materials under thesoil surface, thus sequestering the pathogens<strong>and</strong> beginning the decomposition of theoverturned plant materials. <strong>Field</strong> burial isprobably the most economical <strong>and</strong> practicalmethod for disposing of contaminated plantmaterials in the field.Several types of plows are available foruse in field burial, including disk, moldboard,ripper, <strong>and</strong> chisel plows.In conventional tillage, a moldboard plowturns up the soil to a depth of 8 to 12 inches.This operation buries the contaminated plantmaterials <strong>and</strong> pathogens (disease-causingorganisms) beneath the soil surface <strong>and</strong> canhelp control a plant disease epidemic.Shallow plowing (about 6 inches deep)may be enough to bury the pathogen spores<strong>and</strong> control new infections.125125

Regulatory SynopsisBurialCoordination <strong>and</strong> jurisdictional considerationsBurial should be undertaken only with theexplicit approval of the local <strong>and</strong> state institutions<strong>and</strong> agencies competent in making determinationsabout protecting the environment.States have established orders of priority forcarcass disposal, <strong>and</strong> the incident comm<strong>and</strong>structure must exhaust higher disposal prioritiesbefore undertaking burial activities.The location of the burial activity shouldbe chosen by the members of the incidentcomm<strong>and</strong> structure established by local orstate authorities. Local authorities shouldestablish an intercounty memor<strong>and</strong>um ofunderst<strong>and</strong>ing so that the carcass overflow canbe easily transported to nearby counties forburial.If the carcasses are to be transportedto nearby counties, the incident comm<strong>and</strong>structure must consider the added problemof transportation safety <strong>and</strong> contamination ofother property.126

Pollution <strong>and</strong> other property damage considerationsThe exercise of police power gives governmentalentities <strong>and</strong> agencies wide discretionin making decisions about burying carcassesto protect public health. However, this powerdoes not shield the entities against nuisanceactions if the proper precautions are not taken.Burying carcasses near wells, residences,water bodies, public areas, or property linescould trigger nuisance or other types oflawsuits. Sovereign immunity may not be adefense to such action.If the carcasses are buried in an area notincluded in the list of “suitable areas” asdefined by the local Natural Resource ConservationService, the burial could constitutea violation of the incident comm<strong>and</strong> structurerules <strong>and</strong> serve as a basis for due process,equal protection, nuisance, or other challenges.Because injury to people or property couldtrigger suits claiming violation of site selectionprocedures, the burial decision must be madejointly by the members of the appropriatetechnical group within the incident comm<strong>and</strong>structure.127127

PlanningPlanning considerationsConsult with state solid-waste-managementofficials <strong>and</strong> regional, county, or municipalauthorities to obtain the required permits<strong>and</strong> information about the restrictions onburial methods <strong>and</strong> the permissible volume ofanimal carcasses. States <strong>and</strong> counties may assistby providing draft permits as part of theiremergency management plans.When planning for emergency carcassdisposal by burial, obtain input from privatecontractors (heavy machinery operators), animalproducers, first responders, <strong>and</strong> personnelfrom fire departments, law enforcement,county roads <strong>and</strong> public works departments,departments of transportation, parks <strong>and</strong>recreation departments, regulatory agencies,the USDA Natural Resources ConservationBurialService (NRCS), <strong>and</strong> the Extension service.Maintain a current list of telephone, fax, <strong>and</strong>e-mail information for key representatives ofthe collaborating agencies.Consult the NRCS offices to obtain soilmaps, drainage information, records of seasonallyhigh water table depth, <strong>and</strong> otherrelevant data on environmental impacts.County NRCS offices may maintain a listingof suitability for “<strong>Animal</strong> Mortality Burial(Catastrophic)” by soil map unit.When choosing a burial site, consider itsproximity to wells, residences, roadways,municipalities, public areas, religious sites, archaeologicalzones, property lines, <strong>and</strong> bodiesof water (Table 2).128

Table 2. Capacity <strong>and</strong> setback distances of carcass burial options for various soiltypes.Burial option A B C D E F(Capacity)Trench burial 150 ft 200 ft 500 ft 1,000 ft 1,325 ft VariableL<strong>and</strong>fill — — — — — 40 tons/400 ft 24,300 tons/acreMass burial 150 ft 200 ft 500 ft 1,000 ft 1,325 ft VariableA. Minimum distance from private wells, springs, watercourses, sinkholes, streams, springs (or any source of water usedfor domestic purposes), <strong>and</strong> public areas.B. Minimum distance from residences or property lines.C. Minimum distance from public wells.D. Minimum set-back distance for the burial of disease-infected carcasses near private or public wells for supplying waterfor drinking <strong>and</strong> other uses.E. Minimum distance from pubic roads, highways, <strong>and</strong> parks.F. Sometimes the carcass depth in LF may reach to 6 ft., <strong>and</strong> thus the capacity will be 80 tons of carcass in 400 ft. 2 129129

PlanningAlso when locating a burial site, considervarious soil properties, including slope, texture,permeability, surface fragments (cobblesor stones), the depth to bedrock, <strong>and</strong> the presenceof fractured or cavernous bedrock.Do not locate a burial site in highly permeablesoils such as s<strong>and</strong>s, loamy s<strong>and</strong>s, orold gravel quarries. Locate it in an area withappropriate soil (loam or finer), or provide amixture of clay <strong>and</strong> low-porosity s<strong>and</strong> (finetexture) to cover the carcasses. This coverageprevents seepage into the groundwater<strong>and</strong> maximizes the natural decomposition ofcarcasses.Work with university Extension <strong>and</strong>NRCS personnel to conduct sampling as partof a geotechnical investigation of the proposedburial sites to determine the appropriateareas for excavation of trenches <strong>and</strong> pits. <strong>Plant</strong>o take soil samples to a depth of 2 feet (0.6Burialmeter) below the lowest planned excavationpoint.Before excavation, consider the l<strong>and</strong>filling,trench burial, <strong>and</strong> mass burial dimensionsto estimate the burial area (Table 3). Multiplepits should be spaced at least 20 feet (about 6meters) apart.Also before excavation, contact the localutility company or other State-approvednotification center to check for undergroundutilities in the general work area.Do not bury animal carcasses where thewater table is within 10 feet (about 3 meters)of the bottom of the burial site. High concentrationsof ammonia <strong>and</strong> dissolved solids havebeen reported in groundwater near burial sites<strong>and</strong> around the poultry carcass disposal pits.Fence <strong>and</strong> stake the burial site to keep outunauthorized personnel, pets, wildlife, <strong>and</strong>farm animals.130

Under no circumstance should you buryin trenches, pits, or l<strong>and</strong>fills any carcasses infectedwith transmissible spongiform encephalopathy(TSE), such as bovine spongiformencephalopathy. TSEs are not inactivated byany burial process <strong>and</strong> can seriously threatenthe health of people <strong>and</strong> animals. For burialof animals with chronic wasting disease,check your local <strong>and</strong> state rules.Plan to collect <strong>and</strong> dispose of the carcassesas quickly as possible to avoid negativepublic reaction resulting from the prospectof odors <strong>and</strong> the fear of disease transmission.Rapid burial prevents scavengers <strong>and</strong> verminfrom feeding on the carcasses <strong>and</strong> possiblyspreading diseases.Table 3. Trench/pit/l<strong>and</strong>fill dimensions for burial of animal carcasses.Burial option Volume ratio a Width Depth Length dTrench burial 2–4 4–10 ft 3–12 ft c —L<strong>and</strong>fill — 14 ft 10–20 ft 30 ftMass burial 2–4 4–6 ft b 3–12 ft c —aRatio of the volume of excavated trenches to the volume of carcassesbHistorical data show a width of up to 20 ft, but most new references recommend a width of up to 6 ft.cDepth excludes 2 ft <strong>and</strong> 4 ft of mound to shed rain water <strong>and</strong> divert runoff for trench burial <strong>and</strong> mass burial, respectively.dAs needed to bury a given number of carcasses in trench burial <strong>and</strong> mass burial. Each bovine carcass is equivalent to five adultsheep or five mature hogs <strong>and</strong> requires 5 ft of trench length. Additionally, a 10–14 ft 2 -area is required at the bottom of trench/pit for one mature cattle carcass.131131

PlanningTrain the members of the disposal crew onhow to use safety equipment while excavatingthe trenches or pits, especially for the deepertrenches. Also educate them about safety,biosecurity, <strong>and</strong> operational procedures, suchas how to receive <strong>and</strong> properly stage the carcasses.Plan well in advance to protect the excavatedsoil from erosion until it is used as backfill.Provide equipment for digging pits <strong>and</strong>burying carcasses. Each cubic yard of thebucket size can excavate about 100 cubicyards (about 76.5 cubic meters) of trench perhour.Also provide machinery <strong>and</strong> equipmentfor h<strong>and</strong>ling, loading, unloading, cleaning,<strong>and</strong> disinfecting, as well as for lighting <strong>and</strong>Burialsafety, as described in the “Thermal” chapter.The capacity of the equipment depends onthe amount of carcasses <strong>and</strong> the time required(usually 24 to 48 hours, but up to 72 hours incold climates) for a proper burial process.Provide a backhoe, scraper, bulldozer, orother equipment that can excavate a trench<strong>and</strong>/or burial pit, <strong>and</strong> use tools suited to workingin rocky soils. For information on someof the equipment suppliers, operators, <strong>and</strong>contractors of the trench burial, l<strong>and</strong>filling,<strong>and</strong> mass burial options, see Table 4.Plan to decontaminate the equipment usedfor h<strong>and</strong>ling, packing, storing, <strong>and</strong> conveyingthe carcasses as described in the Transportationsection of the “General Considerations”chapter.132

Table 4. Contractors <strong>and</strong> operating companies for trench burial, l<strong>and</strong>filling <strong>and</strong>mass burial systems.Company Nature <strong>and</strong> capacity of work Contact informationPhillips <strong>and</strong> Jordan, Inc. Contractor of trench burial up 50 tons/hr Robbinsville, NC 28771800-511-6027, 909-337-0083or 919-605-4571www.p<strong>and</strong>j.comRiverside County WasteManagementCarcass l<strong>and</strong>filling 40–80 tons/day14290 Frederick StreetMoreno Valley, CA 92553909-468-3308www.rivocowm.orgCrowder Excavating, Inc. Contractor, up to 10 tons/hr 901 Geddie RoadTallahassee, FL 32304850-576-7176; 800-992-6207or 251-653-6590www.environmentalexpert.comTetra Tech EM, Inc.Consultant <strong>and</strong> contractor for l<strong>and</strong>filling<strong>and</strong> burial up to 50 tons/day8030 Flint StreetLenexa, KS 66214913-894-2600www.tetratech.comThis is not an exhaustive list. No endorsement of companies or individuals or their services mentioned is intended,nor is criticism of similar companies implied.133133

PlanningPlanning for trench burialWhen considering trench burial, plan foran alternative burial method in case no areawith suitable soils is available for trenchburial of large amounts of animal carcasses.Where the soil type is not necessarily suitablefor trench burial, you may need a sourceof clay to supplement the base (bottom layer)of the trench. This clay will minimize the potentialfor environmental contamination.Do not consider sites that have no cutoffs,drainage, or other special design features ifBurialwater (apparent, perched, or seasonal) is likelyto emerge just above the level of the trenchbottom or if it flows down into the trench oraway from the site.Do not allow vehicular traffic to comewithin 4 feet (1.3 meters) of the trench/pitedges. Vehicles may damage the topsoil nearthe trenches/pits <strong>and</strong> may create cracks orfractures in the subsoil, making it permeableto leachate.134

Planning for l<strong>and</strong>fillingLessons learned from the outbreak of foot<strong>and</strong>-mouthdisease in the United Kingdom<strong>and</strong> from outbreaks of poultry diseases in theUnited States suggest that state <strong>and</strong> countycarcass disposal plans should include prior approvalsto use l<strong>and</strong>fills. Prepare contingencycontracts in advance to avoid delays <strong>and</strong> highcosts once an outbreak occurs.When planning for disposal of carcassesin Type I l<strong>and</strong>fills, involve l<strong>and</strong>filling <strong>and</strong>state solid waste management officials.Identify the Type I l<strong>and</strong>fills availablefor disposal of carcasses. Because they areequipped to collect leachate <strong>and</strong> gas, modernor Type I l<strong>and</strong>fills are permitted to accept carcassesexcept those contaminated with prionssuch as mad cow disease, scrapie, or chronicwasting disease.Modern l<strong>and</strong>fills must meet the requirementsof the Resource Conservation <strong>and</strong>Recovery Act, Subtitle D, <strong>and</strong> many otherfederal, state, <strong>and</strong> local regulations. Subtitle Dst<strong>and</strong>s for sanitary l<strong>and</strong>fills that keep wastes“dry” <strong>and</strong> minimize the production of leachate<strong>and</strong> gases, the major byproducts of wastedegradation.135135

PlanningPlanning for mass burialThe base of an excavated pit for mass burialshould be built at least 10 feet (about 3 meters)above the historical high groundwater level.Use unlined, excavated pits for massburial only when the carcasses will be storedPlanning for field burialIf the plants are confirmed to be contaminatedwith pathogens on the Select Agent <strong>and</strong>Toxin List published by the USDA <strong>Animal</strong><strong>and</strong> <strong>Plant</strong> Health Inspection Service (APHIS),the plants may need to be buried at a designated,approved site. The list is located at http://www.aphis.usda.gov/programs/ag_selectagent/ag_bioterr_toxinslist.html.Burialtemporarily <strong>and</strong> disposed of promptly.Be prepared to provide adequate containment<strong>and</strong> collection systems for the leachategenerated in mass burial.A practical option for disposing of annualfield crops is on-site field plowing. Thismethod does not require that the plant materialsbe transported from the farm, <strong>and</strong> air qualityissues are not a concern.L<strong>and</strong>fill burial is a practical choice forperennial field crops <strong>and</strong> nursery greenhouseplants. However, a limiting factor can be the136

proximity of the farm to the l<strong>and</strong>fill. Considerl<strong>and</strong>fill burial also for trees <strong>and</strong> lumber ifthermal destruction is unfeasible <strong>and</strong> if theycan be transported in a timely, cost-effectivemanner.Because plant pathogens are not knownto cause human diseases, the biosecurity <strong>and</strong>environmental safety efforts should focus onpreventing the spread of pathogens to crops inother regions.137137

ProceduresProcedure for trench burialWhen considering trench burial of contaminatedplants or animals—except those contaminatedwith prions—first verify that theyneed to be disposed of immediately. Determinewhether they are contaminated with aggressivepathogens with a great potential to causean epidemic. If they are not considered to bean immediate threat, consider using a naturaldecomposition or crop rotation method.Select a cross-sectional geometry (trapezoidalor rectangular) for the carcass burial site.Determine the length of the trench fromthe cross-sectional area of the trench geometry.The ratio of trench volume to carcass volumeshould be:• 4:1 for burying one to two layers of largecarcasses (1,000 pounds [about 450 kilograms]or more)Burial• 2:1 for burial of two to three layers ofmedium-sized or small carcasses.To determine the length of the trench, seethe calculations in Figure 1.Dig the trenches/pits with relatively levelbottoms according to the dimensions in Table3. Some states, such as Iowa, permit the constructionof burial trenches with vertical wallsif the wall height is less than 5 feet (about 1.5meters). See Figure 2 for details.In general, there must be at least 2 feet(about 0.6 meter) of impermeable soil betweenthe bottom of the trench <strong>and</strong> the water table.The carcasses should be covered with at least2 feet of soil.Adjust the width, depth, <strong>and</strong> side slopesof the trench to match the needs of the equipmentwithout compromising the safety of the138

crew. Prevent trench cave-in hazards by usingOccupational Safety <strong>and</strong> Health Administration(OSHA) st<strong>and</strong>ards for the people buildingor working in or around trenches/pits duringexcavation <strong>and</strong> material emplacement.Where space is limited, use more than onetrench/pit <strong>and</strong> separate them by a minimumof 3 feet (about 0.9 meter) of undisturbed orcompacted soil.To inhibit bloating, which can displace <strong>and</strong>shift the soil or even raise the carcasses to thetrench/pit surface, vent the carcasses beforeburial, especially those of large animals. Thisventing will minimize the accumulation <strong>and</strong>entrapment of gases.For small animals such as poultry ornursery pigs, place a layer of carcasses at thetrench/pit bottom <strong>and</strong> cover it with at least 1foot (about 0.3 meter) of soil. For large animalssuch as hogs or cattle, place the layerof carcasses at the trench bottom <strong>and</strong> cover itwith at least 2 feet (about 0.6 meter) of soil.Repeat this process for up to three layers ofcarcasses in deep trenches/pits (Fig. 2).To reduce potential predator problems in<strong>and</strong> around the trenches/pits during the burialprocess, cover the carcasses daily, particularlyif the burial process takes more than 24 hours.Mound the trenches with at least 2 feet ofsoil, preferably impermeable soil (Fig. 2). Donot try to compact the earth-filled trenches/pitsbecause compaction is difficult to achieve; italso may impede the natural decaying process.Refill the caved-in mounds to prevent accessby vermin (or vectors), <strong>and</strong> the collectionof surface water.139139

ProceduresBurialFigure 1. Length calculation for burial of 100 cattle in deep or shallow trenches.Assumptions1 - Average weight of carcass = 1,000 lb2 - Bulk density of carcass = about 62.4 lb/ft 33 - Volume ratio for a two-layer or one-layer burial trench = 4 ft 3 of trench/ft 3 of carcass4 - Trench depths for one layer <strong>and</strong> two layers = 4 ft (shallow trench) <strong>and</strong> 8 ft (deep trench), respectively5 - Trench width for both cases = 6 ft; two carcasses lie side by side6 - Length of each cattle carcass = about 5 ftSolutionsA. Deep trench1 - Trench length in a deep trench = {(100 cattle)*(1,000 lb/cattle) (4 volume ratio)} ÷ {(62.4 lb/ft 3 ) (8 ft deep)(6 ft wide)} about 130 ft2 - Number of buried cattle in two layers <strong>and</strong> two rows = {(130 ft.)*(2 layers)*(2 rows)} ÷ (5 ft length/carcass) = 104carcassesB. Shallow trench1 - Trench length in shallow trench = {(100 cattle)*(1,000 lb/cattle) (4 volume ratio)} ÷ (62.4 lb/ft 3 )(4 ft deep)(6 ft wide)} ~ 260 ft2 - Number of buried cattle in one layer <strong>and</strong> two rows = {(260 ft)*(2 rows)} ÷ (5 ft long/carcass) = 104 carcasses140

Figure 2. Cross sections (not to scale) of a trapezoidal trench (top) <strong>and</strong> a vertical trenchused for burying carcasses. For massive carcass burial, trenches of up to 12 feet deep with nomore than two 3-foot layers of dead animals are recommended. The bottom soil should be highlyimpermeable, without fractured or cavernous rock.2 ft height of mounding soil with side slopes 3:16 ft height of soil with side slopes 1.5 (horizontal):1 (vertical) containing2–3 layers of carcasses (1–3 ft thick). Each medium or large carcass layeris separated by a 1-ft thick layer of soil.Minimum 2 ft of soil between trench bottom <strong>and</strong> the water table2 ft height of mounding soil with side slopes 3:15 ft of excavated trenches/pits with the vertical wall containing amaximum of 3 layers of small carcasses (each 1 ft thick)Minimum of 2 ft of soil between trench bottom <strong>and</strong> the water table141141

ProceduresProcedure for l<strong>and</strong>fillingAll l<strong>and</strong>fills used must agree to thedelivery of carcasses. Most l<strong>and</strong>fills, eventhose closed to the public, accept carcasses.Confirm with the operator that the l<strong>and</strong>fill isproperly designed <strong>and</strong> is designated to acceptcarcasses, <strong>and</strong> either collect <strong>and</strong> treat theleachate on site or transport it to a waste treatmentplant.For the carcass disposal process, use theconventional equipment that is available inType I l<strong>and</strong>fills. At the l<strong>and</strong>fill site, load thecarcasses evenly at deepest part of the pit toa height of 3 to 6 feet. Cover this layer ofanimal carcasses with a 3-foot (about 0.9-meter) layer of solid waste (household trash)<strong>and</strong> compact it to reduce its porosity.Repeat adding 3-foot layers of solidwaste only, <strong>and</strong> compact each layer until aBurialtotal height of 10 feet is reached (Fig. 3). Thedeepest part of l<strong>and</strong>fill is not necessarily in thepreconstructed <strong>and</strong> lined bottom. The l<strong>and</strong>fillmay have a depth of 20 feet (about 6 meters)of compacted trash.At the end of each day, cover the leftoversolid waste (co-filling materials) with athin layer of soil (less than 1 foot [0.3 meter]thick) to keep the l<strong>and</strong>fill in a sanitary condition<strong>and</strong> to minimize nuisance problems suchas odors, vectors, <strong>and</strong> predators.Mound the top (final) compacted layer ofsolid waste with at least 2 feet (0.6 meter) ofimpermeable soil.Continue to monitor the mound for settling<strong>and</strong> caving-in. Fill <strong>and</strong> recompact themound to shed water <strong>and</strong> to prevent therelease of odors <strong>and</strong> noxious gases.142

Figure 3. Two views of carcass disposal in the Badl<strong>and</strong>s L<strong>and</strong>fill, in Moreno Valley,California (Photos courtesy of Riverside County, Waste Management Department, CA).143143

ProceduresProcedure for mass burialFor mass burial, select a cross-sectionalgeometry (rectangular or trapezoidal) accordingto Figure 4.When excavating to more than 5 feet(about 1.5 meters) deep, prepare the sideslopes with a minimum ratio of 1.5 (horizontal)to 1 (vertical).Prepare gravel drainage channels toconvey the seepage to the leachate collectionsumps. To prevent or minimize seepage, linethe inside (walls <strong>and</strong> bottom) of the trenches/pits with clay or an impermeable membrane.Divert the upstream runoff by buildingBurialberms or a cutoff ditch along the up-gradientside of the pit.In the burial process, place one or twolayers of carcasses in shallow or deep pits.The carcass layers can be a maximum of 2feet [0.6 meter] or one large animal thick. Thedepth of a shallow pit is 3 feet (0.9 meter);that of a deep pit is 10 feet (3 meters).Cover each carcass layer with up to 3 feetof soil (Fig. 4). Fill the pits with excavatedsoil <strong>and</strong> mound them with 4 feet (about 1.2meters) of impermeable soil above the groundlevel (Fig. 5).144

Figure 4. Cross sections of vertical pits (top) for temporary mass burial <strong>and</strong> of a trapezoidaltrench/pit for mass burial of carcasses at preconstructed sites. The walls <strong>and</strong> bottom of thetrenches/pits are built with 2 to 3 feet of impermeable soil such as compacted clay, especially inthe deep pits used for mass burial. The bottom soil should not be highly permeable.4-ft height of mounding soil with side slopes 3:15 ft of excavated trenches/pits containing one layer of carcass (1–3 ftthick) covered with 2-3 ft soilMinimum 2 ft of soil between trench bottom <strong>and</strong> water table4-ft height of mounding soil with side slopes 3:110 ft of excavated trench/pit with side slopes of 1.5 (horizontal):1 (vertical) containing a maximum of 2 layers of carcasses (1–3 ft thick).Each carcass layer is separated by 3 ft of soil.Minimum 2 ft of soil between pit bottom <strong>and</strong> water table145145

ProceduresBurialFigure 5. Great Orton, United Kingdom, in 2005 after mass burial in 2001. (Photo courtesy ofScudamore et al., 2002). http://www.visitcumbria.com/foot<strong>and</strong>mouth.htm, accessed Nov. 6. 2006.146

Procedure for field burialWhen considering field burial of contaminatedplants, first verify whether they needto be disposed of immediately. Determinewhether the plants are contaminated with aggressivepathogens with a great potential tocause an epidemic. If they are not deemed tobe an immediate threat, consider using a naturaldecomposition/crop rotation method.Prepare the equipment (tractors <strong>and</strong> appropriateplows) <strong>and</strong> personnel for the operation.Before field plowing, remove the establishedvegetation (such as trees <strong>and</strong> shrubs) bymechanical or chemical means.Generally, plowing 6 inches deep can effectivelydispose of the pathogens <strong>and</strong> cropresidues, which will ultimately reduce thepathogen population significantly. In severelydiseased areas, consider plowing 12 inchesdeep.Turn but do not compact the soil becauseplant residues generally decompose quicklywhen they are mixed with soil aerobically;they decompose slowly when they are burieddeeply (anaerobically) as compact layers.A time frame of 1 hour per acre is estimatedfor field plowing. Do not plow the areaagain because this may simply return the activepathogens to the soil surface.147147

SafetyBurialTable 5. <strong>Guide</strong>lines for the use of personal protective equipment.Natureof workDirecth<strong>and</strong>ling ofcontaminatedmaterialsNo directh<strong>and</strong>ling ofcontaminatedmaterialsMask/respirator a,b, cZoonoticagentDisposableparticulaterespirator(N95, N99, orN100); half orfull facepieceNonerecommendedNon-zoonoticagentNonerecommendedunless for foot<strong>and</strong>-mouthdiseaseNonerecommendedProtectiveclothing aImpermeableto liquids;depending uponheat situationNo specialclothing required;work clothingappropriate forseasonEye/hearing Gloves a Head/footprotection a protectionEyes: Full facepiecerespirator orindirectly ventedgoggles; contactlenses should notbe worn undergoggles or safetyglasses; considerprescription safetygogglesHearing: Considerdisposable earplugsif necessaryEyes: Safety eyewearHearing: Considerdisposable earplugs,if necessaryGloves: Heavyduty (15–18-mil)chemical resistentgloves that canbe disinfectedor disposed; ifdesired, 10–12-mil nitrile glovesworn underleather glovesWork gloves ifnecessaryFeet: Forworkersh<strong>and</strong>lingcarcasses, steeltoe/steelshankwaterproofboots; forothers, steeltoework shoesor bootsHead: Hard hatFeet: Steel-toework shoes orbootsHead: Hard hataFor a list of vendors recommended by OSHA, visit www.safetyequipment.org.bFor information about a full respiratory protection program, visit www.osha.gov/SLTC/repiratoryprotection/index.cRegulations governing the use of personal protective equipment in hazardous waste operations can be found at 29 CFR 1910.134 <strong>and</strong> 29CFR 1910.156 <strong>and</strong> are summarized in the Safety section of the “General Considerations” chapter of this manual.148

Diseases of concernFor burial methods, the diseases of concerninclude those caused by viruses, bacteria, <strong>and</strong>prions.Viruses <strong>and</strong> non-spore-forming bacteria:Burial is an effective method for controlling thespread of viral <strong>and</strong> non-spore-forming bacteria.For viruses such as those that cause foot<strong>and</strong>-mouthdisease (FMD) <strong>and</strong> classical swinefever (CSF), some of the viruses will persistafter burial. Reports estimate that these virusesmay survive for up to 40 days before theybegin to deteriorate. Although some virusespersist in the soil longer than do non-sporeformingbacteria, burial is still an acceptabledisposal method for them.Precautions must be taken to prevent inhalationof airborne pathogens. Personal protectiveequipment is essential for worker safetywhile the carcasses are being transported <strong>and</strong>h<strong>and</strong>led on site.The diseases for which burial is an acceptablemethod include African swine fever,brucellosis, CSF, contagious bovine pleuropneumonia,FMD, gl<strong>and</strong>ers, highly pathogenicavian influenza, Japanese encephalitis, Q fever,Rift Valley fever, rinder pest, tularemia, <strong>and</strong>vesicular stomatitis.Spore-forming bacteria: Burial is notrecommended for materials infected withspore-forming bacteria because the spores maypersist indefinitely in the soil. Spore-formingbacteria must be incinerated thoroughly. If it isnot possible to incinerate the carcasses immediately,they must remain intact to prevent thespores from spreading into the external environment.Diseases of concern include anthrax.Prions: Extremely high temperatures arenecessary to destroy carcasses infected withprions. Prions are resistant to thermal <strong>and</strong>149149

Safetyenvironmental degradation. The best methodof destruction is fixed-facility burning. Do notbury prion-infected carcasses.Notes on safetyDuring extreme heat, rest periods must beinstated to prevent heat stress <strong>and</strong> dehydration.OSHA recommends establishing a work/restschedule that decreases heat exposure. Developthis schedule according to worker needs.A worker with a core temperature of 100.4°F is considered to be at a heat stress level.To prevent dehydration, allow the workers todrink water at liberty.Heavy equipment operations are inherentlydangerous. Use a safety observer withthe training <strong>and</strong> authority to minimize the riskof dangerous situations.150BurialPrion-based diseases include bovine spongiformencephalopathy.Other suggestions from OSHA:• Implement a training program for managers<strong>and</strong> employees on how to recognize<strong>and</strong> treat heat stress.• Before beginning burial activities,screen the workers to identify existinghealth conditions.• Institute procedural programs guidingthe workers on what to do if a heat-relatedemergency arises.For more information on heat stress <strong>and</strong>work/rest cycles, see the Safety <strong>and</strong> Biosecuritysection of the “General Considerations”chapter of this guide.150

BiosecurityControl of scavenging animals is of paramountimportance in controlling the spread ofdisease from the burial site. Insects, birds, <strong>and</strong>animals that come into contact with the diseasedcarcasses can become vectors, spreadingthe disease outside the site or containmentarea.To prevent easy access by vermin to thecontaminated material, follow the engineeringguidelines for burial sites carefully. Thecarcasses must be covered with soil by theend of the work day to prevent scavenging bywildlife. Institute controls for birds, vermin,<strong>and</strong> other scavengers.Place <strong>and</strong> compact the backfill material soas to prevent or minimize contact of the excavatoror compactor with the carcasses. Compactorsshould not touch the carcass materialBurialuntil the backfill material is in place.The site where animal carcasses are beingdeposited should be closed to all nonessentialvehicles <strong>and</strong> personnel. Keep all othervehicles clear of the area accepting animalcarcasses.Equipment <strong>and</strong> truck drivers must remainin their vehicles while on the burial site toavoid contamination of footwear <strong>and</strong> clothing.Provide another set of personnel on theground to open tailgates <strong>and</strong> offload carcasses.Personnel <strong>and</strong> vehicles must be decontaminatedbefore they leave the disposal site. Seeadditional information in the Safety section ofthe “General Considerations” chapter of thisguide.151

Environmental ImpactsBurialGroundwater pollutionBecause each state sets its own regulationsfor burial of hazardous waste, it is criticalto identify the appropriate authorities beforeselecting a l<strong>and</strong>fill for carcass disposal.It is absolutely essential that you workclosely with State agriculture <strong>and</strong> environmentalregulatory agencies before buryinglarge volumes of contaminated plant <strong>and</strong>animal materials. The appropriate state <strong>and</strong>local agencies are best able to h<strong>and</strong>le considerationssuch as soil type, groundwaterdepth, nearby surface water flows, proximityto drinking water wells, <strong>and</strong> assessment ofground water monitoring approaches.L<strong>and</strong>fill operators must provide the requiredinformation on this topic <strong>and</strong> will have theauthority to deny burial of hazardous carcasswaste at their sites if they believe the environmentalrisk to be greater than acceptable.The most relevant human hazards are thewaterborne protozoa, pathogenic bacteria, <strong>and</strong>transmissible spongiform encephalopathiesthat may be transported by groundwater <strong>and</strong>can contaminate water supplies. Controlledconditions <strong>and</strong> groundwater monitoring willminimize the risk of contamination; they areinstrumental in preventing a public healthhazard.152

Air pollutionThere should be no notable emissionsif the burial methods are followed carefullyaccording to the guidelines presented in thish<strong>and</strong>book.Operating l<strong>and</strong>fillsAll owners/operators of municipal solidwaste l<strong>and</strong>fills must comply with the requirementsfor proper l<strong>and</strong>fill management:• Receipt of regulated hazardous waste:The owner/operator must set up a programto detect <strong>and</strong> prevent the disposalof regulated quantities of hazardouswaste. The program must include proceduresfor r<strong>and</strong>om inspections, recordkeeping, training of personnel to recognizehazardous wastes, <strong>and</strong> notificationof the appropriate authorities if suchConcerns are limited to on-site workerswho will need personal protection equipmentto minimize their exposure to airborne oraerosolized biological agents.waste is discovered at the facility.• Cover material: The owner/operatormust cover the solid waste with at least6 inches of earthen material at the end ofeach operating day to control fires, odors,vectors, scavengers, <strong>and</strong> blowing litter.An approved state or tribe may allow anowner/operator to use an alternative covermaterial or depth <strong>and</strong>/or grant a temporarywaiver of the cover requirement.• Vectors: The owner/operator is responsiblefor controlling populations of vec-153 153

Environmental ImpactsBurialtors, which include rodents, flies, mosquitoes,<strong>and</strong> other animals <strong>and</strong> insectsthat can transmit diseases to humans.Application of cover at the end of eachoperating day generally controls vectors.• Explosive gases: The owner/operatormust set up a program to check for methanegas emissions at least every 3 months.If the limits specified in the regulationsare exceeded, the owner/operator mustimmediately notify the state director (thatis, the official in the state or area responsiblefor implementing the l<strong>and</strong>fill criteria)<strong>and</strong> take immediate steps to protecthuman health <strong>and</strong> the environment.• Access: The owner/operator must controlpublic access to prevent illegal dumping,unauthorized vehicular traffic, <strong>and</strong> publicexposure. Artificial <strong>and</strong>/or natural barriersmay be used to control access.• Storm water run-on/runoff: Theowner/operator must build <strong>and</strong> maintaina control system designed to preventstorm waters from running onto theactive part of the l<strong>and</strong>fill. Runoffwaters must be managed according tothe requirements of the Clean WaterAct, particularly the restrictions on thedischarge of pollutants into water bodies<strong>and</strong> wetl<strong>and</strong>s.• Surface water protection: All l<strong>and</strong>fillsmust be operated in a way that ensuresthey do not release pollutants thatviolate the Clean Water Act.For details in planning, see http://www.epa.gov/epaoswer/non-hw/muncpl/criteria/l<strong>and</strong>big.txt.154

CostThe costs of burial (Fig. 6) follow thecategory definitions from the “General Considerations”chapter of this guide. The cost ofburial depends critically on labor, equipment,<strong>and</strong> outlays for off-site burial <strong>and</strong> relatedtransportation.Table 6 lists estimates of direct costs foron-site burial of cattle, calves, hogs, sheep,lambs, <strong>and</strong> goats. For formulas to estimatedirect costs of burial, see Figure 7.For indirect cost items, see the Cost sectionof the “General Considerations” chapterof this guide.Figure 6. Components of direct <strong>and</strong>indirect costs for burial operations.LaborEquipmentTransportationEnvironmentalimpactsPublic opposition(legal fees)SecurityBurialL<strong>and</strong>Future l<strong>and</strong> use<strong>and</strong> valuePermitting155

CostBurialTable 6. Estimates of direct cost items for on-site carcass burial.Cattle Calves Weaned hogs PreweanedhogsOthers (sheep,lambs, goats)Estimated average cost per carcass ($ per carcass)Labor cost $3.33 $1.67 $1.67 $0.17 $1.67Equipment cost $11.67 $5.83 $5.83 $0.58 $5.83Permitting fee n/a n/a n/a n/a n/aTransportation cost n/a n/a n/a n/a n/aL<strong>and</strong> cost n/a n/a n/a n/a n/aAverage cost per carcass $15.00 $7.50 $7.50 $0.75 $7.50Estimated average cost per ton ($ per ton)Labor cost $8.89 $12.53 $25.06 $55.56 $43.29Equipment cost $31.11 $43.86 $87.72 $194.99 $151.52Permitting fee n/a n/a n/a n/a n/aTransportation cost n/a n/a n/a n/a n/aL<strong>and</strong> cost n/a n/a n/a n/a n/aAverage cost per ton $40.00 $56.39 $112.78 $250.55 $194.81Source: Livestock mortalities <strong>and</strong> burial costs in 2002 by Sparks Companies, cited by a report by the National AgriculturalBiosecurity Center Consortium for Carcass Disposal.156

Figure 7. Formulas to estimate direct variable cost relating to burial.If the hourly labor <strong>and</strong> equipment costs are $10 <strong>and</strong> $35 respectively, the direct variable cost(DVC) of on-site burial can be estimated using the following formulas:• By number of carcasses:DVC = 15.00Q cattle+ 7.50Q calves+ 7.50Q weaned hogs+ 0.75Q preweaned hogs+ 7.50Q others• By weight:Where Q iis the total number of carcasses in animal category i.DVC = 40.00W cattle+ 56.39W calves+ 112.78W weaned hogs+ 250.00W preweaned hogs+ 194.81W othersWhere W iis the total weight in tons of animal category i.If the hourly labor cost <strong>and</strong> equipment cost are C L<strong>and</strong> C Erather than $10 <strong>and</strong> $35, the total directvariable cost (DVC) of on-site burial can be estimated using the following formulas:• By number of carcasses:DVC = (C L+ C E)[0.33Q cattle+ 0.17Q calves+ 0.17Q weaned hogs+ 0.02Q preweaned hogs+ 0.17Q others]• By weight:DVC = (C L+ C E)[0.89W cattle+ 1.25W calves+ 2.51W weaned hogs+ 5.56W preweaned hogs+ 4.33W others]157157

CostBurialEstimating the costs of field burial for plant materialsThe fixed cost is the daily rental cost of atractor equipped with a plow. Below is a caseexample using a 60-horsepower tractor with athree-bottom, 16-inch moldboard plow. However,the field manager must be aware that thefuel consumed <strong>and</strong> the fixed cost will dependon the size of the tractor <strong>and</strong> the moldboardplow.Hourly operation cost = Equipmentrental cost per hour + Hourly labor + Hourlyfuel costThe variable cost is the sum of the laborcost plus the fuel cost during the operation.Using the formula above, if the labor costis $10 per hour, the fuel price is $3 per gallonfor diesel, <strong>and</strong> 1 hour of operation isestimated to plow 1 acre of field, the hourlyoperation cost is estimated to be:Hourly operation cost = Equipmentrental cost per hour + $10 + $16.98Hourly operation cost = Equipmentrental cost per hour + $26.98158

CompostingDefinition <strong>and</strong> objectivesCarcass composting is a disposal processthat conceals animal carcasses under a blanketof organic material to promote decompositionat elevated temperatures.Initially in this process, mesophilic microorganisms(those that grow in moderate temperatures,from 77 to 104 ºF, or 25 to 40 ºC)heat the pile to about 104 ºF (40 ºC). At thisstage, naturally occurring thermophilic microorganisms(those adapted to living at hightemperatures) convert the organic nitrogen <strong>and</strong>carbon compounds into a stable <strong>and</strong> relativelyhomogenous mixture of bacterial biomass <strong>and</strong>humic acid. In the compost pile, the organicnitrogen is mainly from animal sources <strong>and</strong>the carbon compounds are mainly from plantsources.The objectives of carcass composting are to:Summary• Provide the proper conditions for carcassbiodegradation• Inactivate some of the pathogens thatcan spread diseases in soil, plants, animals,<strong>and</strong> humans• Prevent livestock carcasses from generatingenvironmental pollutants, suchas the leaching of nitrogen <strong>and</strong> sulfurcompounds to groundwater <strong>and</strong> theodors that can reduce the quality of life<strong>and</strong> decrease property values• Convert the carcasses into useful endproducts for agricultural l<strong>and</strong>sSeveral factors should be considered whenchoosing the type of carcass compostingsystem. These include costs, system capacity,procedure speed, transportation concerns,environmental risks, <strong>and</strong> the availability ofresources (Table 1).159

CompostingSummaryTable 1. Methods considerations for carcass composting.ConsiderationOutdoor windrowcompostingIn-house windrowcompostingCarcass bincompostingTransportation concerns 1 Yes No YesPathogens inactivated Viruses <strong>and</strong> bacteria Viruses <strong>and</strong> bacteria Viruses <strong>and</strong> bacteriaCapacity for carcass disposal 2 Large Large SmallEnvironmental risk Medium Low MediumRegulatory restrictions Medium Low LowCost 3 Medium Low HighAvailability of resources Medium High LowProcedure speed Low High Medium1If the disaster area meets the disposal site requirements for carcass composting, there is no need for off-sitetransportation.2<strong>Animal</strong> carcasses (tons): Small = < 100 tons; Medium = 100–299 tons; Large = 300 or more tons3Cost estimate (per ton): Low = < $50; Medium = $50–100; High = $100 <strong>and</strong> more (The cutoff points mayvary, depending on factors such as carcass load <strong>and</strong> types, transportation, <strong>and</strong> available disposal facilities.)160

Composting phases <strong>and</strong> systemsCarcass composting has two principalphases: the active phase <strong>and</strong> the curingphase. The composting method can occur inthree major conventional systems: outsidewindrow composting, in-house windrowcomposting, <strong>and</strong> carcass bin composting.The first phase of carcass composting ischaracterized by aerobic (in the presence ofoxygen) reactions, high temperatures, <strong>and</strong>large reductions in biodegradable solids. Thisphase has the potential to produce significantodors.A properly constructed carcass compostingpile should have:• An oxygen concentration of more than 5percent• Particle sizes of the co-compostingmaterials ranging from 0.5 to 2 inches• A pile porosity of less than 40 percent• Bulk densities ranging from 800 to1,200 pounds per cubic yard• An average pH of 5.5 to 9.0The first phase of a carcass compostingoperation should raise the core temperature ofthe pile to about 135 to 140 ºF within 15 days<strong>and</strong> maintain it for several days for poultry orground carcasses, to weeks for larger intactcarcasses. Under these conditions, Mycobacteriumtuberculosis, <strong>and</strong> Salmonella will bedestroyed. If the core temperature is maintainedat 149 °F for 1 to 2 days, the pathogenicbacterial activity <strong>and</strong> weed seed germinationwill be reduced considerably.During the composting process, the mesophilic<strong>and</strong> thermophilic species of bacteria <strong>and</strong>fungi are active. These microorganisms producea variety of antibiotics that destroy somepathogens such as Salmonella <strong>and</strong> Shigella.161161

CompostingIn the first phase of composting, the volume<strong>and</strong> weight of the pile may decrease by asmuch as 50 percent. The porosity of the pilealso will decrease. As the lack of air spacesmakes less oxygen available to the microbes,the compost pile becomes anaerobic, whichincreases the potential for odors. During PhaseI, it is vital that the compost has adequate aerationto maintain a uniform temperature <strong>and</strong>moisture content throughout the pile.The first or active phase of carcass compostingtakes 3 to 12 weeks, depending on thetype <strong>and</strong> weight of carcasses. Most of the biomasscomponents stabilize during this period.In the second or curing phase, aeration isnot a critical factor. During this period, a seriesof slow-rate reactions such as the breakdownof lignin occur at temperatures below105 ºF.SummaryAt the end of Phase II, the internal temperatureof the compost pile ranges from 77 to86 ºF (25 to 30 °C), the bulk density is reducedby 25 percent, <strong>and</strong> the finished productappears dark brown to black <strong>and</strong> is free ofunpleasant odors when turned.Figure 1 shows the temperature changesof the carcasses during the two phases ofoutside windrow composting. Figure 2 showsthe average temperatures of carcasses duringin-house windrow composting.The time required for Phase II of compostingdiffers according to the carcass size:• Small carcasses (poultry): 10 days• Medium-sized carcasses (sheep <strong>and</strong>swine): 90 <strong>and</strong> 180 days• Heavy carcasses (cattle <strong>and</strong> horses): 240days162

Figure 1. Example of internal carcass temperatures during the first 63 days after thecarcasses are placed in a windrow compost pile. (Courtesy of Dr. John Kube of Elanco <strong>Animal</strong>Health, Greenfield, IN)160150140Degrees F1301201101009080Top averageBottom averageCompost (not carcass) average1 7 14 21 28 35 42 49 54 63Day163163

CompostingSummaryFigure 2. An example of a daily log of internal poultry carcass temperatures during 45days of in-house windrow composting. (Courtesy of Dr. Nathaniel Talbante of the Universityof Maryl<strong>and</strong> College Park <strong>and</strong> Rob Malone of the University of Delaware)160Temperature (°F)1401201008060401 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 2728 29 30 31 3233 34 35 3637 38 39 40 4142 43 4445Day164

Speeding decompositionYou can speed the decomposition of thecarcasses considerably—by up to 50 percent—by grinding them before composting. Grindingprovides uniform porosity <strong>and</strong> suitable conditionsfor aeration. It also eliminates the needto mechanically turn the carcasses three timesduring the two phases, a common requirementwhen intact carcasses are composted.Organic co-composting materials suchas peanut shells, wood chips, <strong>and</strong> tree trimmingsare less absorbent than straw for intactcarcasses. Grinding these materials with thecarcasses makes them readily available for thecomposting process. These organic materialsare smaller (less than 2 inches) than straw.Carcass grinding also reduces the maximumweight ratio of the bulking agent tocarcass from:• 4:1 to 1:4 for carcass bin composting• 3:1 to 1:3 for in-house windrow composting• 3:1 to 1:3 for outside windrow compostingUse of biofiltersA biofilter is a layer of organic materials(mainly from plants) placed over the compostpile to:• Deodorize the gases released from theactive pile• Maintain the proper moisture, pH, nutrients<strong>and</strong> temperature in the pile• Enhance the microbial activities in thepileFor the first 3 days, a compost pilecovered with a biofilter layer has very pronouncedodor <strong>and</strong> gaseous emissions. Later,the odor level is reduced by more than 80percent.165165

CompostingSummaryEnd productThe end product of carcass composting isa homogenous, dark brown, soil-like materialcalled “humus.” This material contains mostlymesophilic bacteria <strong>and</strong> is suitable for use as asoil amendment.Some carcass parts, such as pieces ofskull, hooves, teeth, <strong>and</strong> large bones, mayremain intact in windrows (outside <strong>and</strong> inhouse)<strong>and</strong> in carcass bin compost piles butare not identifiable in ground carcass composting.However, these materials are relativelysmall <strong>and</strong> brittle or rubbery <strong>and</strong> degradewhen exposed to nature.Overall, the decomposition rate of intactcarcasses in a properly managed compost pileduring the two phases (mainly the first phase)is about 2.2 pounds (1 kilogram) per day.166

Outdoor windrow composting: DescriptionThe goal of outside windrow compostingis the natural decomposition of dead animals.Carcasses are buried above ground in a staticpile (trapezoidal shape) with no walls orroofs. They are buried beneath a mound of organicmaterials <strong>and</strong> in the presence of oxygen.The carcass windrow piles are mounded toshed rainfall; to better control moisture, temperature,gases, <strong>and</strong> odors; <strong>and</strong> to maintain anadequate biofilter cover. The recommendedheight for a pile is 5 to 7 feet (1.5 to 2.1 meters).An advantage of outdoor windrow compostingis that it can be adapted for a largenumber of dead animals after a catastrophicevent. This method is feasible for any size ofanimal, <strong>and</strong> the length of a windrow can beincreased to accommodate additional carcasses.This method also enables the workers toload, unload, <strong>and</strong> turn the pile from all sides.However, because outdoor windrow compostpiles are built in open spaces unprotectedfrom weather, rain, or wind, they are exposedto more adverse weather conditions than arethe components of other methods. These conditionscan affect the degradation process ofoutdoor windrow compost piles.Windrow composting of ground carcassesalso requires more care <strong>and</strong> protection againsthealth hazards during material preparation<strong>and</strong> pile formation. Figures 3 through 9 showthe different stages of intact <strong>and</strong> ground carcasscomposting.167167

CompostingFigure 3. Carcasses on top of a windrowbase before being covered. (Courtesy of Dr.John Kube of Elanco <strong>Animal</strong> Health, Greenfield,IN)SummaryFigure 4. Carcasses partially coveredin a windrow pile with carbon amendments.(Courtesy of Dr. John Kube of Elanco <strong>Animal</strong>Health, Greenfield, IN)168

Figure 5. Contents of a cattle carcass windrow without initial grinding after 2 months ofactive composting. Note the steam rising from the exposed windrow. (Courtesy of Dr. John Kubeof Elanco <strong>Animal</strong> Health, Greenfield, IN)169169

CompostingSummaryFigure 6. Loading of a carcass into a large-scale carcass grinder <strong>and</strong> windrows of compostedground carcasses. (Courtesy of Dr. John Kube of Elanco <strong>Animal</strong> Health, Greenfield, IN)170

Figure 7. Ground carcass mixed with amendments ready for composting.(Courtesy of Dr. John Kube of Elanco <strong>Animal</strong> Health, Greenfield, IN)171171

CompostingFigure 8. A 200-foot-long windrow of 65ground carcasses. (Courtesy of Dr. John Kubeof Elanco <strong>Animal</strong> Health, Greenfield, IN)SummaryFigure 9. A view of compostingwindrows of ground carcasses. (Courtesyof Dr. John Kube of Elanco <strong>Animal</strong> Health,Greenfield, IN)172

In-house windrow composting: DescriptionAn in-house windrow composting pileis built inside a livestock barn or house toreduce labor, minimize the workers’ exposureto pathogens, reduce biosecurity risks, <strong>and</strong>minimize exposure to the elements.Carcass in-house composting occursin a poultry house after birds infected withcontagious diseases such as avian influenzaare euthanized. One method of euthanizingis the foaming technique (Figs. 10 <strong>and</strong> 11).Chemicals in the foam, such as mixtures ofhydrocarbon surfactants, alcohols, propyleneglycol, solvents, <strong>and</strong> stabilizers, produce foambubbles that fill the breathing passageways ofbirds (called hypoxia), causing death.In-house windrow composting limitsthe transmission of diseases from the farm,reduces the risks of groundwater <strong>and</strong> air pollution,allays public concerns over diseaseexposure, <strong>and</strong> protects the composting pilesfrom extreme weather conditions.This composting method is relatively lowcost <strong>and</strong> uses readily available farm equipment.This system of composting protectsthe pile from scavengers <strong>and</strong>, to some extent,from outside disease vectors.This method degrades carcasses efficiently,quickly, <strong>and</strong> in a controlled manner,containing the disease inside the barn <strong>and</strong>inactivating the pathogens in the carcasses<strong>and</strong> litter for poultry. It also probably providesenhanced composting because environmental173173

Compostingparameters such as moisture <strong>and</strong> temperaturecan be controlled more easily in an in-housewindrow composting system than in outdoorwindrow composting systems. In addition,there is no need to transport contaminatedcarcasses.Figure 11 shows two views of a windrowcomposting pile inside a poultry house.Microbial activity (mesophilic <strong>and</strong> thermophilic)within a well-constructed in-housewindrow composting pile can generate <strong>and</strong>maintain temperatures in the range of 130 to150 ºF (54 to 66 ºC) for several weeks, whichis sufficient to inactivate the avian influenzavirus.SummaryFigure 10. In-house foaming of a poultryhouse. (Courtesy of G.W. Benson, Universityof Delaware, Newark, DE)174

Figure 11. The euthanizing of diseased turkeys. (Courtesy ofEric S. Bendfeldt, Virginia Cooperative Extension, Blacksburg, VA)175175

CompostingSummaryFigure 12. Two views of preparing windrow piles for in-house composting. (Courtesy ofEric S. Bendfeldt, Virginia Cooperative Extension, Blacksburg, VA)176

Carcass bin composting: DescriptionThe goal of carcass bin composting is thenatural decomposition of dead animals buriedin a contained system. The carcasses are buriedin a mound of organic material <strong>and</strong> in thepresence of oxygen. The system may be builtof any material that is structurally adequate toconfine the compost pile material.The system consists of a:• Primary bin to actively compost thecarcasses (Phase I)• Secondary bin to cure the carcass compost(Phase II)• Storage bin to store the mature compost(Phase III)In bin composting, the contained structuremay or may not be covered by a roof.Unroofed bins are simple <strong>and</strong> inexpensive<strong>and</strong> can be constructed of large round balesplaced end to end to form three-sided enclosures(bale composters). Although the pile isprotected from predators, pests, <strong>and</strong> runoff,it is susceptible to precipitation <strong>and</strong> weathervariations.Roofed bins have the advantages of reducedweather effects, less unwanted moisture,potentially less leaching from the pile,<strong>and</strong> better working conditions for the operatorduring inclement weather.Although carcass bin composting is amore environmentally controlled processthan is outside windrow composting, it is notfeasible for h<strong>and</strong>ling large amounts of farmcarcasses.177177

Regulatory synopsisCoordination <strong>and</strong> jurisdictional considerationsThe decision on whether to use compostingfor carcass disposal should be madejointly by the members of an incident comm<strong>and</strong>structure that has been established byState or local authorities.Local authorities should have an intercountymemor<strong>and</strong>um of underst<strong>and</strong>ing inplace so that the carcasses can be easily transportedto the county where the nearest facilityfor composting is located. If the carcasses areto be transported to nearby counties for composting,the incident comm<strong>and</strong> structure mustCompostingconsider the added problems of transportationsafety <strong>and</strong> contamination of other properties.Composting should be undertaken onlywith the explicit approval by the institutions<strong>and</strong> agencies that are competent in makingdeterminations about protecting the integrityof the environment.States have established orders of priorityfor carcass disposal, <strong>and</strong> the incidentcomm<strong>and</strong> structure must exhaust the higherdisposal priorities before undertaking compostingactivities.178

Pollution <strong>and</strong> other property damage considerationsThe exercise of police power gives widediscretion to governmental entities <strong>and</strong> agenciesin making decisions about carcass disposalto protect public health. However, thispolice power does not shield the governmentalentities from nuisance actions if the properprecautions are not taken.The main challenge in the compostingprocess is to make sure that the materials usedto build the system are impervious to water<strong>and</strong> rot resistant. If constructed properly,composting systems usually pose no problemsof odors or flies. However, the failure to buildthe compost facility properly could triggernuisance or other types of lawsuits. Sovereignimmunity may not be a defense to such anaction.Because injury to people or property couldalso trigger suits similar to those based onnuisance, the decision to use composting mustbe made jointly by the members of the appropriatetechnical group within the incidentcomm<strong>and</strong> structure.179179

PlanningPlanning considerationsWhen planning to dispose of carcasses bycomposting, include in the discussions peoplefrom many fields of expertise: private contractors,heavy machinery operators, animalproducers, <strong>and</strong> personnel from regulatoryagencies, fire departments, transportationdepartments, the Extension service, parks <strong>and</strong>recreation departments, the USDA-NaturalResources Conservation Service, county roads<strong>and</strong> public works departments, <strong>and</strong> other firstresponders.To minimize the neighbors’ exposure toodors or dust, plan to locate the compostingfacility far from water resources <strong>and</strong> downwindof homes <strong>and</strong> other dwellings (Table 2).The facility should have all-weather access<strong>and</strong> clearance from underground <strong>and</strong> overheadutilities. The site also should not interferewith other operations or traffic.CompostingWorker training should include:• Educating the composting crew aboutoperational procedures, such as those onworking safely, receiving <strong>and</strong> stagingdead animals properly, <strong>and</strong> maintainingbiosecurity around carcasses• Training the personnel involved with theon-site carcass composting on propercomposting procedures• Educating the operators of compostingcompanies on how to produce a goodorganic soil amendment while protectingthe environment through properdisposal of composted animal carcassesPlan also to use personal protective equipment,including working suits, disposableoverboots, disposable gloves, <strong>and</strong> respiratorsaccording to Occupational Safety <strong>and</strong> HealthAdministration (OSHA) st<strong>and</strong>ards for train-180

ing, equipment maintenance <strong>and</strong> compostingin confined spaces.Consider the issues related to sanitizing theequipment such as shredders or grinders <strong>and</strong>h<strong>and</strong>ling, packing, storing, <strong>and</strong> conveying thecarcasses to the composting site, as describedin the Transportation section of the “GeneralConsiderations” chapter in this guide.Plan to provide ample co-compostingmaterials in the piles. A ratio of carbon to nitrogen(C:N) ranging from 25:1 to 40:1 mustbe maintained. This will provide the energyneeded for the organic materials to decomposeas well as minimize the production ofodors during the active composting process.The weight ratio of some organic materials tocarcasses is specified in Table 2.Co-composting materials include organicmaterials such as sawdust (C:N~100),oats (C:N~60), barley straw (C:N~40 to 60),corn silage (C:N~40), poultry litter (C:N~10to 30), ground corncobs (C:N~100), baledcornstalks (C:N~65), wheat straw (C:N~125),semi-dried screened cattle manure (C:N~20),hay (C:N~15 to 30), leaves (C:N~55), paperpulp or paper mill sludge (C:N~60 to 80), ricehulls (C:N~120), cotton gin trash (C:N~20 to40), shrub trimmings (C:N~15), <strong>and</strong> bulkingagents such as tree trimmings (C:N~70).Plan to grind the carcasses <strong>and</strong> organicmaterials to speed the composting process <strong>and</strong>to increase the composting capacity.The finished composted product of poultry,sheep, swine, <strong>and</strong> cattle carcasses can beapplied on coarse-textured soils that are lowin organic matter. The product will increasethose soils’ organic matter <strong>and</strong> water-holdingcapacity. Determine the compost applicationrates according to crop needs, <strong>and</strong> perform acompost analysis that includes measuring thenitrogen, phosphorus, <strong>and</strong> potassium levels inthe end product.181181

PlanningCompostingTable 2. Carcass composting specifications.ConsiderationCarbon sources to mortality ratioCompost site1:1 (w/w) a2:1 (w/w) b4:1 (w/w) cSpecificationHeight: 3 ft dDistance: 300 ft eSlope: 1–3% fBin volume (ft 3 /1,000 lb) Phase I: 150Phase II: 450Storage: 450Lumber for bin walls (pressure treated) Width: 2 ftLength: 6–8 ftThickness: 1 in studs, 2 x 6 inEnd product Organic matter: 35–70%pH: 5.5–8.0Bulk density: 40 lb/ft 3Moisture content: 35–40%aFor high C:N materials such as sawdustbFor medium C:N materials such as littercFor low C:N materials such as strawdHeight of composting site above the high water-table leveleSetback distance from sensitive water resources (such as streams, ponds <strong>and</strong> wells)fTo provide proper drainage <strong>and</strong> prevent ponding of water182

Planning for outdoor windrow compostingWhen planning an outdoor windrow compostingoperation, identify a crowned location(highest point) on which to build the concretepad or base on the compost site.To control water infiltration, use low-permeabilitysoil as the initial layer for the compostingpile on a concrete pad or on a base.Provide plastic liners that are 0.24 inchthick <strong>and</strong>:• 12 feet wide <strong>and</strong> the length of the windrowfor the composting base of smallcarcasses (poultry)• 13 feet wide <strong>and</strong> the length of the windrowfor the composting base of mediumcarcasses (sheep <strong>and</strong> swine)• 15 feet wide <strong>and</strong> the length of the windrowfor the composting base of largecarcasses (hogs, sows, cattle, <strong>and</strong> horses)183183

PlanningComposting184Planning for in-house windrow compostingFor an in-house windrow composting system,plan to establish <strong>and</strong> train rapid-responseteams (with team leaders) within each poultrycomplex to oversee the sanitation, depopulation,<strong>and</strong> in-house composting processes.Make sure that the poultry house ceiling ishigh enough for a loader to build a compost pileto about 4 to 6 feet tall. If it is not high enough,compost the carcasses infected with contagiousdiseases in an outdoor windrow system.Plan to ventilate the in-house area becausethe composting piles will release large volumesof gases such as ammonia (NH 3) that are toxic.If there is not enough litter in the poultryhouse, use other supplemental organic materialssuch as sawdust <strong>and</strong> woodchips. To calculatethe amount of litter required for in-house windrowcomposting, use the formula in Figure 13.To ensure proper in-house windrow composting,use skilled compost laborer(s) <strong>and</strong>operators of skid-steer loaders, <strong>and</strong> consult withrepresentatives of state <strong>and</strong> federal agencies,poultry producers, <strong>and</strong> composting experts.Table 3 shows the required number of skidsteerloaders <strong>and</strong> workers for each broiler houseof euthanized poultry.Plan to provide pressure washers, a tillerattachment, a hay fork, scoops, <strong>and</strong> midsizeskid-steer loaders (1.25-1.5 cubic yard bucket),which are more suitable for in-house h<strong>and</strong>ling<strong>and</strong> conveying of materials.Plan to keep the poultry house depopulatedfor 2 to 4 weeks after the in-house windrowcomposting ends to allow for testing to ensurethat the composting windrow (if kept in thehouse) is free of pathogens <strong>and</strong> for sanitizationof the poultry house.

Figure 13. Calculation of the minimum amount of litter or other organic material requiredfor the carcass in-house windrow composting. (Tablante <strong>and</strong> Malone, 2005)Given:• Floor area of poultry house: 20,000 square feet (40 feet x 500 feet)• Number of broilers in the poultry house: 25,000• Amount of litter required per pound of carcass weight: 0.8 cubic foot• Average weight of each broiler: 4 pounds• Thickness of litter base: about 3 inchesSolution:• Total carcass weight: 100,000 pounds (4 pounds x 25,000 broilers)• Ratio of carcass weight to floor area: 5 pounds of carcass weight per square foot(100,000 pounds ÷ 20,000 square feet)• Required depth of litter: 4 cubic inches of litter required per carcass (5 pounds ofcarcass weight per square foot x 0.8 cubic foot of litter per pound of carcass weight)• Additional litter required for each additional inch of litter base: about 1,670 cubic feet(20,000 square feet ÷ 1 inch/12 inches /foot = 1,667 cubic feet)185185

PlanningCompostingTable 3. Minimum loader <strong>and</strong> worker requirements to compostchicken from broiler houses. (Tablante <strong>and</strong> Malone, 2005)Number of poultryhousesNumber of skid-steerloadersNumber of workers2 2 44 3 66 4 88 5 10Planning for carcass bin compostingWhen creating a carcass bin compostingoperation, plan to locate an appropriate compostingsite as described in Table 2. Use newfacilities such as poured concrete, pole construction,<strong>and</strong> hoop houses.For low-cost options, use existing facilitiessuch as machine sheds, corn cribs, or cattlesheds if their ceilings are high enough to allowthe front-end or skid loader to lift <strong>and</strong> turn thecompost in the composting site.Use modular bins by building compartmentsin the bins, which will increase thecapacity <strong>and</strong> efficiency of the bin composting.Enclose the bins on three sides, leaving anopening wide enough to accommodate a frontendloader.Plan for the primary (Phase I), secondary(Phase II), <strong>and</strong> storage (Phase III) bin volumesas prescribed in Table 2.186 186

ProceduresCompostingOutside windrow composting: Procedures for Phase IFor outside windrow composting, thecomposting site must be fenced to prevent accessby livestock <strong>and</strong> scavenging animals.Create a moisture barrier by spreadingappropriate plastic liners on selected crushed<strong>and</strong> compacted rock, particularly if the watertable is high or the site drains poorly.For the composting process, use the appropriategrinding or milling equipment, includingtub grinders, tub mills, hammer mills,continuous mix pug mills (machines in whichmaterials are mixed, blended, or kneaded intoa desired consistency), <strong>and</strong> vertical grinders.Similarly, use a bale processor to grind baledcornstalks, hay, straw, <strong>and</strong> grass.Grind the co-composting materials for 15to 45 minutes to provide enough air space betweenthe compost materials. If a large crusher(able to h<strong>and</strong>le more than 8,000 pounds perday) is available, grind the carcasses to 1 to2 inches along with the organic materials toprovide uniform raw materials for the compostingprocess.Do not mix the organic materials for morethan 5 minutes. Prolonged mixing decreasesthe particle size because of breakage, reducingthe air spaces in the compost pile.To produce homogenous materials forthe composting operations, use suitable batchmixers (either truck- or wagon-mounted), includingmixers with augers, rotating paddles,rotating drum mixers, or slats on a continuouschain.Reduce the amount of fresh organic materialsneeded by mixing in separated solidsfrom liquid manure or the finished compostedcarcasses from a previous composting batch(up to 50 percent by volume of the co-com-187

Proceduresposting materials). These can be used to recyclethe heat <strong>and</strong> bacteria in a new windrow.The h<strong>and</strong>ling volume of the finished compostis reduced if it is partially recycled as a cocompostingmaterial for a new windrow.Use skid-steer or front-end loaders to:• Build <strong>and</strong> maintain the composting pilesfor forming windrows• Lift <strong>and</strong> place the carcasses on the compostpiles• Mix the co-composting materials properly• Cover the carcasses• Move the compost as needed for aeration• Feed a compost screener or shredderwith the finished product (Figs. 6 <strong>and</strong> 7)Use organic materials <strong>and</strong> bulking agentsto build the windrow pile for small, medium,Compostinglarge, or very large carcasses as shown inFigures 14, 15, <strong>and</strong> 16.Do not stack medium-sized, large, or verylarge carcasses on top of one another. Do notstack small carcasses more than the thicknessspecified in Figure 14 without an appropriatelayer of co-composting materials between twocarcasses.Cover the compost pile with a biofilterlayer during Phase I (active) <strong>and</strong> Phase II (curing)of composting to reduce odors, preservemoisture, <strong>and</strong> prevent access by insects <strong>and</strong>birds (as the most important carriers of diseasemicroorganisms). This layer will prevent thetransmission of many microorganisms fromthe carcasses to livestock or humans.A minimum biofilter depth of 0.5 foot isrecommended.188

Figure 14. Cross-sectional dimensions (not to scale) of a trapezoidal windrow forsmall carcasses (such as poultry). (Source: A. Kalbasi <strong>and</strong> S. Mukhtar (2006), Biological<strong>and</strong> Agricultural Engineering Department, Texas A&M University)TWHPlastic liner, 0.24 in thick, used as an impermeable layer under the composting materialsThree layers of mixed organic materials containing plant <strong>and</strong> animal sources (such as litter) to enrich bacterialactivities; they are used as a base layer <strong>and</strong> between carcass layers, each up to 1 ft thickLayer of bulking agent, such as wood chips, 0.5 ft thickLayers of poultry carcasses, each layer up 1 ft thick containing more than one rowBWBiofilter layer containing mainly plant organic materials on top <strong>and</strong> two sides of the windrow, up to 1 ft thickBottom width (BW) = 15 ft (3.6 m); top width (TW) = 5 ft (1.5 m); height (H) depends on the thickness of carcasses189189

ProceduresCompostingFigure 15. Cross-sectional dimensions (not to scale) of a trapezoidal windrow for mediumcarcasses (such as sheep <strong>and</strong> swine). (Source: A. Kalbasi <strong>and</strong> S. Mukhtar (2006), Biological <strong>and</strong>Agricultural Engineering Department, Texas A&M University)TWHBWPlastic liner with thickness of 0.24 in used as an impermeable layer under the composting materialsTwo layers of mixed organic materials containing plant <strong>and</strong> animal sources (such as litter) to enrich bacterialactivities; they are used as a base layer <strong>and</strong> top of carcasses, 1.5 <strong>and</strong> 1 ft thickLayer of moistened bulking agent, 1 to 1.5 ft thickLayer of medium-sized carcassesBiofilter layer containing mainly plant organic materials on top <strong>and</strong> two sides of the windrow, 1 ft thickBottom width (BW) = 13 ft (3.9 m); top width (TW) = 1 ft (3 m); height (H) depends on the carcass thickness190

Figure 16. Cross-sectional dimensions (not to scale) of a trapezoidal windrow for large(hogs <strong>and</strong> sows) <strong>and</strong> heavy (cattle <strong>and</strong> horses) carcasses. (Source: A. Kalbasi <strong>and</strong> S. Mukhtar(2006), Biological <strong>and</strong> Agricultural Engineering Department, Texas A&M University)TWHPlastic liner, 0.24 in thick, used as an impermeable layer underneath composting materialsTwo layers of mixed organic materials containing plant <strong>and</strong> animal sources (such as litter), 2 <strong>and</strong> 1 ft thick,respectively, used to enrich bacterial activities are used as a base layer <strong>and</strong> top of carcassesLayer of moistened bulking agent, 1.5–2 ft thickLayer of large or heavy carcassesBiofilter layer containing mainly plant organic materials on top <strong>and</strong> two sides of the windrow, 1 ft thickBWBottom width (BW) = 15 ft (4.5 m); top width (TW) = 1 ft (3 m); height (H) = depends on the carcass thickness191191

ProceduresUse self-propelled or towed windrow turnersto adequately mix the ground carcasses <strong>and</strong>organic materials during Phase II of the intactoutdoor windrow composting processes. Windrowturner capacities range from 800 to 3,000tons per hour.To haul water or other effluent <strong>and</strong> spray iton the windrows, use pump trucks, honey wagonswith pumps, or tanker trucks with side-deliveryflail-type spreaders.Maintain the moisture content in the carcasscompost pile in a range of 40 to 60 percent (wetbasis). Use analytical equipment or the h<strong>and</strong>squeezemethod to test the windrow moisturecontent.If the compost moisture content in Phase I islow (less than 40 percent) <strong>and</strong> the pile temperatureis very high (150 °F), rake back the compostpile biofilter cover (up to 1 foot) <strong>and</strong> add enoughwater (see the h<strong>and</strong>-squeeze method) to bring thecompost moisture level to nearly 50 percent.CompostingThe h<strong>and</strong>-squeeze methodSqueeze a h<strong>and</strong>ful of compostmaterial firmly several times to forma ball. If the ball crumbles or breaksinto fragments, the moisture content ismuch less than 50 percent. If it remainsintact after being gently bounced threeor four times, the moisture content isnearly 50 percent. If the ball textureis slimy with a musty, soil-like odor<strong>and</strong> liquid squeezes out, the moisturecontent is more than 50 percent.If the carcasses are infected withdiseases that can be transmitted tohumans, personal protective equipmentmust be worm.If liquid begins to leach out of the pile,spread an absorbent organic material such assawdust around the pile.192

If the compost temperature does not riseto expected levels within the first 2 weeks ofcomposting, evaluate the initial pile formulationfor proper C:N ratio (30:1) <strong>and</strong> the mixtureof co-composting materials <strong>and</strong> carcasses.Control water run-on to <strong>and</strong> runoff from thecomposting site. Divert all runoff from nearbyanimal production facilities <strong>and</strong> treat it througha vegetative filter strip or infiltration area.For non-zoonotic agents, use disposablegloves to h<strong>and</strong>le <strong>and</strong> test the temperature,moisture, <strong>and</strong> odor of the pile.To monitor <strong>and</strong> record the physical <strong>and</strong>chemical properties of the composting system,provide the necessary instruments <strong>and</strong> supplies,including long-stemmed thermometers,pH meters, bulk-density testing devices, odortestingmaterials (resealable plastic bags), <strong>and</strong>log books to record the composting activities<strong>and</strong> status along with test results.Insert a temperature probe carefully <strong>and</strong>straight down into each quadrant of the pile toallow daily <strong>and</strong> weekly monitoring of internaltemperatures at depths of 10, 20, 30, <strong>and</strong> 40inches after stabilization during Phases I <strong>and</strong>II of composting. Use the average to representthe compost pile temperature.Maintain the air spaces in the windrowpiles by turning (or lifting <strong>and</strong> dropping) thecompost materials rather than pushing them toa new space.Use windrow turners or bucket loaders<strong>and</strong> rotating-tiller turners (rototillers) to turnthe windrow composting piles. If a bucketloader is used, the bucket contents should bedischarged in a cascading manner rather th<strong>and</strong>ropped as a single mass, for greater pile aeration.After the carcass compost has matured,recycle or store the finished product to beginanother pile afterward or, where appropriate,l<strong>and</strong>-apply the finished product as a soilamendment or as a fertilizer.193193

ProceduresCompostingOdor evaluation for compostTo evaluate the odor of the compost pile during the Phase I, place two h<strong>and</strong>fuls ofmaterial in a resealable plastic bag. Close the bag <strong>and</strong> let it sit for an hour, or place it insunlight for 5 to 10 minutes.If immediately after the bag is opened, the compost has a musty soil odor (dirt cellarodor), it is ready for Phase II.If the compost has a sweetish odor (such as like that of slightly burnt cookies), thedecomposition process needs a couple more weeks to mature.If the compost odor is like that of rotting meat or flesh, if it is overpowering,reminiscent of manure, or if it has a strong ammonia smell but less of a manure odor, thecompost process is not complete (mainly because the internal temperature is less than130 °F <strong>and</strong> the pile is anaerobic) <strong>and</strong> requires more organic materials <strong>and</strong> aeration fortemperatures to rise to acceptable levels.194

In-house windrow composting: Procedures for Phase IBegin the procedures for in-house windrowcomposting by making a list of the availablesupplies, equipment, <strong>and</strong> materials. Collectsite-specific data such as the age of the birds, thedepth of the litter in each part of the house, themoisture <strong>and</strong> condition of the litter, the locationof the carcasses, the access to the end doorsfor delivery of the co-composting material <strong>and</strong>compost removal, the ability to turn the piles, thepoultry house dimensions, the ceiling height, <strong>and</strong>the number <strong>and</strong> average weight of the carcasses.Unless specified otherwise in this procedure,follow the processing steps regarding organicmaterial preparation, mixing, pile formation,<strong>and</strong> turning as described in the section onoutside windrow composting.Before euthanizing the birds, let them consumeall the feed, then turn off the fans, closethe curtains, <strong>and</strong> raise the feeders <strong>and</strong> waterersin the barn. Preparations must be made in amanner that does not create an animal welfareissue.Provide a minimum of 1.5 pounds of litter(at a density of 30 pounds per cubic foot) perpound of bird: Place 1 pound of litter per poundof bird in the layer, <strong>and</strong> use the remaining 0.5pound for the cap <strong>and</strong> cover.Create a windrow base of litter about 1 footthick with a 10- to 12-foot-wide base. Scoopthe dead birds with a loader <strong>and</strong> lay them on topof the base. Spread the carcasses evenly with arake or pitchfork.Repeat the layering procedure of litter <strong>and</strong>poultry carcasses as described in Figure 14. Ifthe poultry house is not tall enough for a 6-foothighwindrow, make only two layers to keep thepile less than 4 feet tall.To construct windrows in free-span houses,till the caked litter in the house to form a goodbase 4 to 6 inches deep for the windrow. Avoid195195

Procedurescompacting the windrow base with equipmenttraffic. Use any remaining litter to cap the windrow.Use a tiller attached to a skid-steer loaderor tractor-driven power take-off (PTO) vehicleto shred the carcasses. To ensure adequateshredding, make at least two passes of the tillerwith sharp tines at a high rotational speed. Analternative to shredding is to crush the carcassesunder the rubber tires of a skid-steer loader.Every day during composting, monitor <strong>and</strong>record the temperatures of the compost pile.Measure the temperature at the outside edges<strong>and</strong> from inside the center of the pile every 20feet along the length of the windrow. Turn thewindrow pile when its temperature drops belowabout 125 °F (52 °C) or 10 to 14 days afterthe composting process begins. After turningthe windrow, the temperature should equal orexceed that in an unturned windrow.If the windrow temperature peaks <strong>and</strong> dropsCompostingbelow 105 °F within the first 2 weeks, aeratethe compost by slowly lifting it with a hay forkalong the length of the pile. This method doesnot disturb the cap but allows oxygen into thepile. If no fork is available or space is limited,the pile can be completely turned <strong>and</strong> recapped.About 3 to 4 weeks after the windrow isbuilt, inspect the material in the pile to evaluatethe decomposition of the carcasses. At thisstage, the carcasses should be reduced to bones<strong>and</strong> feathers, with little flesh remaining.Inspect the decomposition of all fleshymaterials <strong>and</strong> sample <strong>and</strong> test the pile to verifythat the targeted virus has been eliminated.After complete pathogen inactivation has beenconfirmed, move the pile from inside the poultryhouse to an outdoor location (after 6 weeksof composting) <strong>and</strong> store it for 2 to 3 weeks in alitter storage shed or another appropriate roofedsite with an impervious base (plastic sheet) foradditional curing.196

Two new fact sheets provide details on in-house poultry composting have been published:• <strong>Guide</strong>lines for In-House Composting Poultry Mortality as a Rapid Response to AvianInfluenza, by the Virginia Department of Environmental Quality <strong>and</strong> VirginiaCooperative Extension• In-House Composting of Poultry Mortality due to Catastrophic Disease, by the University ofMaryl<strong>and</strong>–College Park <strong>and</strong> the University of DelawareProcedures for Phase I: Carcass bin compostingWhen building composting bins, determinetheir volume based on the amount ofstorage required <strong>and</strong> the specifications inTable 2 for Phases I <strong>and</strong> II. Build bin compostersof any material (such as concrete, wood,<strong>and</strong> hay bales) that is structurally adequate toconfine the compost pile material <strong>and</strong> resistlateral loads.Simple, economical structures can bemade by placing large, round bales end to endto form three-sided enclosures or bins. Theseare sometimes called bale composters.Locate the structure in a free space with(preferred) or without a roof <strong>and</strong> situate thestructure so as to protect the pile from predators,pests, <strong>and</strong> precipitation runoff.Build a 5-inch-thick impervious compactedor concrete floor with a weight-bearingfoundation to accommodate the heavy machinery,to allow for all-weather use, <strong>and</strong> to197197

Proceduresprevent the contamination of the soil <strong>and</strong> surroundingareas.To improve accessibility during wetweather, build <strong>and</strong> pave the access ways (10to 28 feet wide) to the primary, secondary, <strong>and</strong>storage bins with concrete, fly ash, or compactedcrushed rock.Build a concrete bin by using a concretefloor along with a poured bin wall 6 inchesthick. The bin entrance should be at least 2feet wider than the loading bucket.The bins should be between 5 <strong>and</strong> 6 feettall. Determine the width of the bins by thewidth of carcass-h<strong>and</strong>ling equipment. However,to ease pile h<strong>and</strong>ling <strong>and</strong> to minimize thebin construction costs, do not make the binswider than 8 feet.Design the bin front so that the carcassesneed not be lifted above the door. AccomplishCompostingthis with removable drop boards that slideinto a vertical channel at each end of the binor with doors that split horizontally, whicheveris more practical.Design hinged doors to swing back flatagainst the adjoining bins <strong>and</strong> allow the doorsto swing open by using removable hinge pinsat both ends. Allow the top of the door to folddown for easier loading of the lower portionof the bin.Before adding carcasses to a fresh bin,build a 1.5- to 2-foot-thick base (substrate) ofco-composting material such as sawdust ora litter-shavings mixture, including up to 50percent composted manure <strong>and</strong> straw.Rake back 6 inches of the co-compostingmaterial <strong>and</strong> place the first layer of carcassesinside the bin. Leave a minimum base depth of1 foot to absorb the carcass fluids <strong>and</strong> leachate198

(runoff fluid). Surround <strong>and</strong> cover the first layerof carcasses with the co-composting material.To ensure that the carcasses are subjectedto peak temperatures, place them at least 8 to12 inches from the sides, front, <strong>and</strong> rear of thecompost bin. Spread the organic material sothat it can be placed completely around eachcarcass <strong>and</strong> between the carcass layers.Provide a 1-foot-thick layer of inactivematerials (organic material with very lowmoisture <strong>and</strong> very low compaction) betweenthe layers of carcasses to insulate <strong>and</strong> maintainthe compost temperature.Immediately after placement, cover thecarcasses with a 1-foot-thick layer of biofiltermaterials. Check the carcasses daily to ensurethat they are surrounded by the cover material.Continue to cover any exposed parts tocontrol leachate or odors that attract flies,vermin, or predators.In a farrowing operation, place the fetal <strong>and</strong>nursery pigs in bins separate from the sows;these pigs require less composting time.Alternatively, if a sow has been in a binfor a few weeks, finish by filling it with babypigs that may require only a couple of monthsbefore the turning process.In a log book, record the bin number, date,time, <strong>and</strong> ambient <strong>and</strong> compost temperaturesevery day.199199

ProceduresCompostingProcedures for Phase II: Outdoor windrow composting,in-house windrow composting <strong>and</strong> carcass bin compostingIn Phase II of the carcass composting process,add moisture to the partially compostedmaterials to reheat <strong>and</strong> reactivate the compostpile <strong>and</strong> to obtain an acceptable end product.After moving the pile to the secondarystorage area, add moisture if necessary <strong>and</strong>cover the compost pile with a minimum of4 inches of co-composting materials. Thiswill insulate the pile, reduce the potential forodors, discourage predators, <strong>and</strong> ensure thedecomposition of the remaining carcass parts.The composted finished product can beidentified by a brown color (similar to humus)<strong>and</strong> a faint or lack of unpleasant odor uponpile turning.Commercial stability tests for odor concentrations,carbon dioxide production,oxygen consumption rate, NH 3concentration,color, <strong>and</strong> seed germination are available toconfirm that the compost is suitable for l<strong>and</strong>application.200

SafetyCompostingTable 4. Personal protective equipment guidelines for composting.Natureof worka, b, cMask/respirator ProtectiveZoonoticagentDisposableparticulaterespirator(N95, N99, orN100); half orfull facepieceNon-zoonoticagentNonerecommendedunless forfoot-<strong>and</strong>mouthdiseaseclothing aEye/hearing Gloves a Head/footprotection a, c protectionDirecth<strong>and</strong>ling ofcontaminatedmaterialImpermeableto liquids;considerbased on heatEyes: Full facepiecerespirator orindirectly ventedgoggles; contactGloves:Heavy duty(15–18 mil)chemicalFeet: For workersh<strong>and</strong>lingcarcasses, steeltoe/steel shanksituation lenses should not be resistant waterproofworn under goggles gloves that boots; for others,or safety glasses; can be steel-toed workconsider prescription disinfected shoes or bootssafety goggles or disposed Head: Hard hatHearing: Considerdisposable earplugs ifnecessaryNo direct NoneNoneProtective Eyes: Safety eyewear, Work Feet: Steel-toedh<strong>and</strong>ling of recommended recommended coveralls if neededgloves if work shoes orcontaminatedHearing: Earplugs necessary bootsmaterialor muffs if workingHead: Hard hataround noise hazardsaSee www.safetyequipment.org for a list of vendors from OSHA.bFor information on a full respiratory protection program, see www.osha/gov/SLTC/respiratoryprotection/index.cRegulations governing use of personal protective equipment in hazardous waste operations can be found at 29 CFR 1910.134<strong>and</strong> 29 CFR 1910.156 <strong>and</strong> are summarized in the Safety section of this guide.201

SafetyDiseases of concernCompostingIn composting, the diseases of concerninclude those caused by viruses, bacteria, <strong>and</strong>prions.Viruses <strong>and</strong> non-spore-forming bacteria:Composting is an effective methodof eliminating viral <strong>and</strong> non-spore-formingbacteria. Precautions must be taken to preventinhalation of airborne pathogens.While the carcasses are being transported<strong>and</strong> h<strong>and</strong>led on site, the use of personalprotective equipment is essential for workersafety. Under proper conditions, these types ofdiseases can be inactivated by the compostingmethod.Diseases include Q fever, foot-<strong>and</strong>-mouthdisease, vesicular stomatitis, Rift Valley fever,brucellosis (B. melitensis, B. abortus, <strong>and</strong> B.suis), rinderpest, contagious bovine pleuropneumonia,gl<strong>and</strong>ers, Japanese encephalitis,African swine fever, classical swine fever,highly pathogenic avian influenza, <strong>and</strong> tularemia.Spore-forming bacteria: Any bacteriathat will form endospores should not be compostedbecause the temperatures will not behigh enough to inactivate this type of bacteria.Diseases include anthrax.Prions: Extremely high temperaturesare necessary to destroy prion-infected carcasses.Carcasses suspected of contaminationwith prion diseases should not be compostedbecause the temperatures reached will not behigh enough to inactivate these agents.Diseases include bovine spongiformencephalopathy, chronic wasting disease, <strong>and</strong>scrapie.202

Notes on safetyHeat stress: See the guidelines on heatstress in the Safety <strong>and</strong> Biosecurity sectionin the General considerations chapter of thisguide.First aid: First aid should be available tothe employees at all times.Safety observers: Movement of heavyequipment is dangerous; use caution <strong>and</strong> asafety observer.Specialized equipment: Grinders <strong>and</strong>crushers are sometimes used in compostingoperations. Use care when near this dangerousequipment.Watch for loose or dangling clothing,equipment, or hair when working aroundthis equipment; use a safety observer.203203

BiosecurityOf paramount importance in preventingdiseases from spreading from the compost siteis the control of scavenging animals. Insects,birds, <strong>and</strong> other animals may come into contactwith diseased animals <strong>and</strong> can becomevectors, spreading the disease outside the siteor containment area.Carefully follow the engineering guidelinesfor compost sites to prevent easy accessby vermin to contaminated material.The area on site where animal carcassesare being deposited should be closed to allnonessential vehicles <strong>and</strong> personnel. All otherCompostingvehicles should be kept clear of the area acceptinganimal carcasses.Equipment <strong>and</strong> truck drivers shouldremain in their vehicles while on the compostingsite; provide another set of personnelon the ground to open tailgates <strong>and</strong> unloadcarcasses.Decontamination of vehicles <strong>and</strong> anycontaminated personnel must occur beforethe vehicles leave the disposal site. For moreinformation on these procedures, see theSafety <strong>and</strong> Biosecurity section of the “GeneralConsiderations” chapter in this guide.204

Environmental ImpactsCompostingGroundwater pollutionBefore beginning any composting work,it is essential that you coordinate closely withState <strong>and</strong> local health <strong>and</strong> public works authorities.State, county, <strong>and</strong> local regulations differon the distances that composting sites canbe located away from bodies of water, thegroundwater table, <strong>and</strong> other natural features.Soil pollutionNo soil pollution concerns are associatedwith composting of contaminated animals unlessthe composting sites are uncontrolled orinadequately engineered.Some tissue may remain after the compostingprocess. This tissue can be groundYour State <strong>and</strong> local health <strong>and</strong> public worksauthorities can provide guidance on theseregulations.Nearby l<strong>and</strong>fill operators may be able toprovide information on the depth to groundwatertables <strong>and</strong> on the appropriate points of contact inthe State <strong>and</strong> local agencies having jurisdictionover any burial or composting activity.<strong>and</strong> disposed of in l<strong>and</strong>fills as solid waste inaccordance with State <strong>and</strong> local solid wasteregulations.All waste will be monitored <strong>and</strong> testedbefore shipment of potentially dangerousmaterials.205

Environmental ImpactsCompostingAir pollutionThere are no notable emissions for thecomposting methods described if the guidelinesin this manual are followed carefully.The air-pollution concerns associated withcomposting are limited to the on-site workers,who will need personal protective equipmentto minimize their exposure to airborne oraerosolized agents.206

CostComposting costsThe cost breakdown relating to compostingdestruction follows the category definitionsin the “General Considerations” chapter ofthis guide. Figure 17 shows the components ofdirect <strong>and</strong> indirect costs.For specific indirect cost items, see the“General Considerations” chapter of this guide.CompostingFigure 17. Components of direct <strong>and</strong>indirect costs for composting operations.Direct costsThe direct fixed cost of composting carcassesdepends on the facility’s capacity. The initialinvestments for two major carcass facilities—windrow composting <strong>and</strong> bin composting—differ dramatically. Table 5 shows the initialinvestment <strong>and</strong> direct fixed cost estimates forwindrow composting with an annual capacity of10,000 tons per acre. Table 6 shows the directvariablecost estimates of on-site composting.LaborMachineryCompostingmaterialsTransportationInterest rateDepreciationL<strong>and</strong>EnvironmentalimpactsOthers207

CostComposting208Table 5. Initial investment <strong>and</strong> annual direct fixed cost estimates ofwindrow composting with an annual capacity of 10,000 tons per acre.Investment itemPrice adjustment(2002, $)Life expectancy(years)Annual fixed cost(2002, $)L<strong>and</strong>L<strong>and</strong> a 1,618 97Sediment b 705 20 78Fencing ($6.75/ft) c 7,353 20 809Subtotal 9,676 984SurfacingGrading compaction 6,589 20 7252 in. asphalt 82,096 10 13,1354 in. asphalt 94,727 10 15,1566 in. asphalt 189,453 15 23,997Subtotal 372,865 53,013Equipment <strong>and</strong> machinery cWater pump 587 10 94Thermometer 261 10 42Scale 19,572 20 2,153Front-end loader 146,135 10 23,382Compost turner 168,316 10 26,931Screening system 87,616 10 14,018Shredding system 118,669 10 18,987Subtotal 541,156 85,607Total investment cost 923,697 139,604Source: “A cost analysis of municipal yard waste composting,” by Mitch Renkow, Charles Safley <strong>and</strong>Jeff Chaffin, North Carolina State University. 1993. http://www.p2pays.org/ref/12/11875/aDollars per acre bDollars per linear foot cDollars per unitNote: The annual interest rate is assumed to be 6 percent.

Table 6. Estimates of direct variable cost items of on-site composting of animal carcasses.CattleCalvesWeanedhogsPreweanedhogsOthers (sheep,lambs, goats)Estimated average variable cost per carcassLabor $18.88 $6.74 $3.17 $0.14 $1.83Equipment $23.57 $8.42 $4.20 $0.19 $2.51Composting material (sawdust) $6.10 $2.17 $1.09 $0.05 $0.63Permitting n/a n/a n/a n/a n/aTransportation n/a n/a n/a n/a n/aAverage variable cost per carcass $48.55 $17.33 $8.46 $0.38 $4.97Estimated average cost per tonLabor $50.34 $50.71 $47.65 $47.50 $47.49Equipment $62.84 $63.29 $63.20 $63.00 $65.23Composting material (sawdust) $16.28 $16.28 $16.33 $16.28 $16.28Permitting n/a n/a n/a n/a n/aTransportation n/a n/a n/a n/a n/aAverage variable cost per ton $129.46 $130.28 $127.18 $126.78 $129.00Source: Livestock mortality <strong>and</strong> burial cost in 2002 by Sparks Companies, cited in the National Agricultural Biosecurity CenterConsortium for Carcass Disposal (NABCCD) Working Group report209209

CostCompostingFigure 18. Formulas for estimating the direct variable costs of carcass composting.If the hourly labor cost <strong>and</strong> equipment cost are $10 <strong>and</strong> $35, respectively, the formulas toestimate the direct variable costs (DVC) are• By number of carcasses:DVC = 48.55Q cattle+ 17.33Q calves+ 8.46Q weaned hogs+ 0.38Q preweaned hogs+ 4.97Q othersWhere Q iis the total number of carcasses in animal category i.• By weight:DVC = 142.71W cattle+ 143.61W calves+ 140.19W weaned hogs+ 139.75W preweaned hogs+ 142.20W others)Where W iis the total weight in tons of animal category i.(Figure continued on next page)210

Figure 18. (Continued)If the hourly labor cost <strong>and</strong> equipment cost are C L<strong>and</strong> C E, rather than $10 <strong>and</strong> $35,respectively, the formulas to estimate the direct variable cost (DVC) are• By number of carcasses:DVC = (1.89C L+ 0.67C E+ 6.10)Q cattle+ (0.67C L+ 0.24C E+ 2.17)Q calves+ (0.32C L+ 0.12C E+1.09)Q weaned hogs+ (0.01C L+ 0.01C E+ 0.05)Q preweaned hogs+ (0.18C L+ 0.07C E+ 0.63)Q others• By weight:Where Q iis the total mortality of animal category i.DVC = (5.03C L+ 1.8C E+ 16.3)W cattle+ (5.07C L+ 1.8C E+ 16.3)W calves+ (4.76C L+ 1.8C E+16.3)W weaned hogs+ (4.75C L+ 1.8C E+ 16.3)W preweaned hogs+ (4.75C L+ 1.86C E+ 16.3)W othersWhere W iis the total weight in tons of animal category i.Besides labor, equipment, <strong>and</strong> compostingmaterial costs, disposal costs include the transportationcost, which depends mainly on thedistance that the animal carcasses are moved.211211

RenderingDefinition <strong>and</strong> objectivesIn a carcass rendering procedure, animalcarcasses are broken down thermally <strong>and</strong> sterilizedin a sealed <strong>and</strong> controllable containerusing pressurized steam; the process convertsthe carcasses into safe, nutritional, <strong>and</strong> valuableproducts.The objective of rendering is to convertfarm carcasses, except those infected withtransmissible spongiform encephalopathy(TSE), into pathogen-free feed protein <strong>and</strong>other valuable end products while reducingthe negative effects of the carcasses on people<strong>and</strong> the environment.Carcass rendering separates the fat, protein,<strong>and</strong> water from a variety of dead animals<strong>and</strong> sterilizes the final products <strong>and</strong> byproducts,which include tallow, meat, bone meal,<strong>and</strong> wastewater.SummaryRendering should not be used for carcassesinfected with TSE. These materials shouldbe disposed of by incineration or alkalinehydrolysis.Although carcass rendering occurs as dryor wet rendering, either in a batch or continuousflow mode, only dry rendering is discussedhere. The processing steps for renderingare illustrated in Figure 1.A rendering plant should process at least60 to 70 tons of carcasses per day, assuming 20working hours per day to justify the processingcosts. Independent rendering facilities maynot be able to process large numbers of animalcarcasses. Storing the livestock carcasses onsite could extend a facility’s capacity.The raw materials used by independentrendering plants include the relatively fresh212

carcasses of cattle, pigs, goats, sheep, poultry,<strong>and</strong> other animals that perish during transportor natural disasters or because of animaldiseases.Improper carcass rendering can produceover- <strong>and</strong> under-heating. Although overheatedproducts have lower feed values, they do notpose hazards to human health. Under-processingconditions will reduce the efficiency of thefat extraction <strong>and</strong> may generate contaminatedproducts <strong>and</strong> byproducts that can spread diseasesto soil, plants, animals, <strong>and</strong> people. Theresulting health hazards or aesthetic concerns,such as odors, can reduce the quality of life<strong>and</strong> decrease property values near a renderingplant.Proper rendering inactivates most biologicalcontaminants except prions <strong>and</strong> hardyorganisms. It also produces meat <strong>and</strong> bonemeal at a volume of 20 percent of that of theraw carcasses.Although the risk of spreading prions hasbeen very low, feeding proteins of mammalianorigin to cattle <strong>and</strong> other ruminant animals(such as sheep <strong>and</strong> goats) is prohibited. Thisfeed rule has prevented emerging problemsrelated to this issue.The carcasses used for rendering are primarilyground to particle sizes ranging from0.4 to 1.2 inches (10 to 30 millimeters). Largerparticles would require much more time fortheir cores to reach the desired temperature.The ground carcasses are fed at ambienttemperatures into a horizontal <strong>and</strong> cylindricalcooking vessel equipped with a heating system(such as a steam-jacketed shell along withan agitator, a rotating steam-heated shaft <strong>and</strong>bundles, <strong>and</strong> rotating steam-heated disks). Thecarcasses are then rapidly heated to 212 °F(100 °C) at a steam jacket shell internal pressureof 40 pounds per square inch (2.8 bar).213

RenderingSummaryThe agitating <strong>and</strong> heating system convertsthe fat into a hot slurry that optimizes the heattransfer to the raw material. After most of thefree moisture has evaporated, the temperatureof the cooked material quickly rises to 245 to285 °F (depending on the equipment design),which is maintained for at least 30 or 10 minutes,respectively. When the moisture contentof the mixed materials falls below 10 percent,the resulting meal is deep-fried in hot fat.Continuous dry rendering units areequipped with automatic controls for choppinglarge particles <strong>and</strong> grinding <strong>and</strong> uniformlymixing the raw material. Revolving beatershafts facilitate the further breakdown offatty tissues <strong>and</strong> maintain the amount of time<strong>and</strong> the temperature required for the cookingprocess.The heating, cooking, <strong>and</strong> separationprocesses occur simultaneously, with no needfor manual operation. Figure 2 illustratestwo general views of the equipment used in arendering plant.214

Description of a continuous dry-rendering systemAs shown in Figure 1, animal carcassesare received in temporary storage or rawmaterial bins (1), conveyed by a raw materialconveyor (2), <strong>and</strong> discharged across a magnet(3) to remove any ferrous metal contaminations.A raw material grinder (4) reduces the rawmaterial to a uniform particle size for h<strong>and</strong>ling<strong>and</strong> improved heat transfer in the cookingstep. The ground raw material is fed at acontrolled rate from a metering bin (5) into acontinuous cooker (6).The discharge is transported to a drainerconveyor (7). The drainer conveyor separatesthe liquid fat from the solids, which are thenconveyed from the drainer conveyor by adischarge conveyor (8).In the discharge conveyor, the solids fromthe drainer conveyor are combined with thesolids discharged from the settling tank (10)<strong>and</strong> from the decanter-type centrifuge (11).The solids from the discharge conveyorgo to the screw presses (9), which reduce thefat content of the solids to 10 to 12 percent.The solids that bypass the screw presses in theform of pressed cake go to the pressed cakeconveyor for further processing into meal.The fat removed in the screw presses goesto the pressed fat conveyor (12), which separatesthe large particles from the liquid fat <strong>and</strong>returns them to the discharge conveyor. Thefat from the pressed fat conveyor is pumpedto the settling tank (10). Fat discharged fromthe drainer conveyor (7) goes into the settlingtank (10).In the settling tank, the heavier bone <strong>and</strong>protein particles settle to the bottom, wherethey are discharged by the screw conveyor(not shown) into the discharge conveyor (8).Liquid fat from the settling tank is pumped215

Renderinginto the centrifuge (11), which removes theresidual solid impurities from the fat. Thesolids from the centrifuge go to the dischargeconveyor (8). The clarified fat is transportedfor further processing or for storage as finishedfat.Water vapor exits the continuous cooker(6) through a vapor duct system that generallyincludes an entrainment trap to separate <strong>and</strong>return the entrained particles to the continuouscooker. The vapor duct system transportsthe vapor stream to an air-cooled condenserSummary(13), which condenses the water vapor. Otherforms of condensers, such as direct contact orindirect shell <strong>and</strong> tube units, may be used.Noncondensable gases are removed fromthe condenser by a noncondensable fan. Odorousgases generated at various points in theprocess are collected by a ductwork system<strong>and</strong> are transported along with the noncondensablegases from the condenser to anodor-control system (not shown) to neutralizeodors.216

Figure 1. A schematic diagram of machinery, equipment, <strong>and</strong> material flow ina continuous dry rendering process. (Adapted from a diagram courtesy of Dr. DavidMeeker of National Renderers Association, Alex<strong>and</strong>ria, VA)1Rawmaterialbins2Raw materialconveyor3 Magnet4 Raw materialgrinder13Noncondensable fanAir-cooled condenserTo odorcontrol systemMetering bin56Condensate towater treatmentContinuous cookerBoiler steam275°8 Discharge conveyor7Drainer conveyor10 Settling tank911 CentrifugePress #1 Press #2Centrifugefeed pumpRaw materialVapor or steamSolidsLiquid fat12Pressed fatconveyorPressed cake conveyorPressed fat pumpFinished fatto storagePressed cake to meal processing217

RenderingSummaryFigure 2. Two views of the equipment used for rendering processes. (Courtesy of Dr. DavidMeeker of National Renderers Association, Alex<strong>and</strong>ria, VA)218

Regulatory SynopsisRenderingCoordination <strong>and</strong> jurisdictional considerationsThe decision to use rendering as a carcassdisposaloption should be made jointly by themembers of the appropriate technical groupwithin the incident comm<strong>and</strong> structure establishedby the State or local authorities.Local authorities should have an intercountymemor<strong>and</strong>um of underst<strong>and</strong>ing inplace so that the carcasses can be easily transportedthrough nearby counties to the nearestrendering facility.If carcasses are to be transported out ofthe county for rendering, the incident comm<strong>and</strong>structure must consider the added problemsof transportation safety <strong>and</strong> the possiblecontamination of other property.Rendering should be undertaken only withthe explicit approval by the institutions <strong>and</strong>agencies that are competent to make determinationsabout protecting the integrity of theenvironment.States have established orders of priorityfor carcass disposal, <strong>and</strong> the incident comm<strong>and</strong>structure must exhaust the higher disposalpriorities before undertaking a renderingactivity.Converting a rendering plant into a “disposalrendering” plant may result in situationsin which the incident comm<strong>and</strong> structuremay be responsible for its decontaminationor other forms of restitution before returningthe facility. In addition, the incident comm<strong>and</strong>structure may have “bought” the plant by usingit in such a manner.219

Regulatory SynopsisRenderingPollution <strong>and</strong> other property damage considerationsThe exercise of police power gives governmentalentities <strong>and</strong> agencies wide discretionin making decisions about carcassdisposal to protect public health. However,the exercise of police power does not shieldgovernmental entities against nuisance actionsif the proper precautions are not taken. In thecase of rendering, private firms engaged inrendering could also face legal challenges.The two main problems posed by renderingare pathogen residue in the renderedproduct <strong>and</strong> disease spread when the carcassesare transported. If these problems occur, theycould trigger a nuisance claim or lawsuit.Sovereign immunity may not be a defense tosuch an action. Private firms that trigger thespread of disease may be subject to both civil<strong>and</strong> criminal actions.220

PlanningPlanning considerationsPlan to coordinate with the managers ofthe rendering plants <strong>and</strong> make all the necessaryarrangements such as the transportation<strong>and</strong> delivery of carcasses to the plant. Themanagers of the facilities under considerationmust be willing to stop all other operationsto render the “infected” carcasses. Table 1lists the Web sites <strong>and</strong> contact information forseven rendering plants in the United States.Consider the issues related to h<strong>and</strong>ling,packing, storing, <strong>and</strong> conveying the carcassesto the rendering plant as described in theTransportation section of the “General Considerations”chapter of this guide.Although most rendering companies willcharge a fee for pickup, plan to use their servicesfor transporting large amounts of animalcarcasses. Consider that a mass mortalityevent may require multiple trips between theRenderingfarm <strong>and</strong> the rendering facility. If the renderingcompany does not offer pickup service,or the farm is out of the range of the pickupservice, alternatives must be considered.Determine in advance whether the localrendering plants will accept infected ornoninfected carcasses <strong>and</strong>, if so, the volumeaccepted per day.Before any incident occurs, train therendering plant personnel on carcass rendering,biosecurity, work safety issues, <strong>and</strong> theuse of personal protective equipment basedon the Code of Practice approved October 18,2004, by North American Rendering Industry(http://www.animalprotein.org).The fallen infected carcasses must be renderedunder close veterinary supervision <strong>and</strong>surveillance.Plan to minimize the risk of contamina-221

PlanningRenderingTable 1. Some of the U.S. rendering plants that may acceptcontaminated carcasses.*CompanyBaker CommoditiesLos Angeles, CADarling InternationalIrving, TXGriffin IndustriesCold Spring, KYPascal EnterprisesDallas, TXSacramento RenderingSacramento, CAAnamax Corp.Green Bay, WIValley ProteinsWinchester, VAContact informationJames Andreoli323-268-2801j<strong>and</strong>reoli@bakercommodities.comRoss Hamilton972-281-4461rhamilton@darlingii.comRobert Griffin859-781-2010Rgriffin@griffinind.comMel Roshanraven214-871-0300melr@pascalenterprises.comMichael Koewler916-363-4821michaelkoewler@aol.comBob Pfeil920-494-5233bpfeil@anamax.comJ.J. Smith540-877-2590jjsmith@valleyproteins.com*Source: David Meeker, Vice President, Scientific Services, National Renderers Association,801 N. Fairfax St., Suite 205, Alex<strong>and</strong>ria, VA 22314. Office: 703-683-2633, Fax: 703-683-2626. For information, visit http://www.renderers.org/Member_Directory/index.htm.222

tion from carcass materials entering <strong>and</strong> offinished products exiting the processing plantby careful <strong>and</strong> precise inspection, an on-sitechemical control program, proper housekeeping<strong>and</strong> sanitation of the facility/equipment,<strong>and</strong> inspection <strong>and</strong> decontamination of theload-out <strong>and</strong> transport trucks, cars, vessels,<strong>and</strong> containers.Each carcass rendering plant shouldparticipate in the <strong>Animal</strong> Protein ProducersIndustry (APPI) program to test for Salmonella(pathogenic bacteria) in the meat <strong>and</strong> bonemeal <strong>and</strong> have at least one person on site whohas received training by the APPI or a certifiedtrainer from an equivalent program.All of the equipment of rendering plantsthat comes into contact with carcasses <strong>and</strong>their derivatives should be easily cleanable<strong>and</strong> washable.Plan to control the harmful compounds,such as nitrogen <strong>and</strong> sulfur compounds, thatmay leach from wastewater of the renderingplant to groundwater.Rendering 1 ton of carcass materials produces1.5 to 2 tons of wastewater. Additionalwastewater results from the washing <strong>and</strong>cleaning of rendering equipment. To decreaseorganic loads, mechanically aerate <strong>and</strong> oxidizethe wastewater. Rendering plants haveon-site wastewater treatment systems.Add appropriate chemical flocculants,such as aluminum sulfate, to the wastewaterto reduce the available phosphorus to permissiblelevels so the wastewater can be directlydischarged or l<strong>and</strong>-applied. This processconverts the soluble phosphorus to insolublephosphorus that can be removed by a settlingprocess.223

ProceduresKeep unauthorized personnel <strong>and</strong> uninfectedcarcasses out of the plant area used forprocessing infected carcasses.Perform rendering processes within 24to 48 hours of an animal’s death unless it isstored at a proper temperature (at least 40 °F,or 4.4 °C). It is easier to remove hides, hair,<strong>and</strong> paunch from fresher carcasses than fromthose that are highly decomposed <strong>and</strong> havereduced quality of fat <strong>and</strong> protein.To ensure that the carcass materials arenot processed too quickly, control <strong>and</strong> recordthe input rate relative to the size of the renderingvessel <strong>and</strong> control the temperatures indifferent locations in the vessel.Properly maintain the carcass-receiving<strong>and</strong> finished-product sections as “dirty”<strong>and</strong> “clean” areas of the rendering plant, <strong>and</strong>keep them separated from each other. Preventworkers from moving from the receiving areaRenderingto the finished-product area unless they havetaken cleaning <strong>and</strong> disinfection measures. Restrictequipment movement to keep contaminationfrom the receiving area from moving tothe finished-product area.To produce rendered products with lowlevels of microorganisms, routinely sanitizethe equipment <strong>and</strong> maintain the tools usedon the processing lines <strong>and</strong> in the facilities.“Dirty” areas <strong>and</strong> all processing equipmentshould be sanitized with steam or suitablechemicals (see the EPA list of approveddisinfectants in the “General Considerations”chapter) that produce sterilized animal meal<strong>and</strong> fat.Prevent the drainage of liquids from dirtyto clean areas to avoid contaminating thefinished products <strong>and</strong> their transportation system.Direct the airflow within the plant fromthe finished-product area to the receiving area.224

Ensure that the rendering plant has adeodorization system (including a condenser,chemical scrubber, gas burner, <strong>and</strong> biofilter)<strong>and</strong> implements procedures to monitor odors<strong>and</strong> investigate <strong>and</strong> resolve odor-related complaints.Perform all of the prescribed renderingguidelines for cooking time <strong>and</strong> carcasstemperature to produce high-quality tallow,meat, <strong>and</strong> bone meal that is free of pathogens.Monitor the cooking process periodically. Agood indication of cooking is a slight grittinessin <strong>and</strong> fibrous nature of the cookedcarcasses (cracklings). Slippery cracklingsindicate under-cooking; a lack of fiber indicatesovercooking.Ensure that the rendered products aretested for disease agents, <strong>and</strong> document thatthe rendering process has produced a safeproduct. If a disease agent has been identifiedin a finished product, dispose of it using anappropriate carcass disposal method.225

SafetyRenderingTable 2. Personal protective equiment guidelines for rendering.Natureof workDirecth<strong>and</strong>ling ofcontaminatedmaterialNo directh<strong>and</strong>ling ofcontaminatedmaterialZoonoticAgentDisposableparticulaterespirator(N95, N99,or N100);half or fullfacepieceMask/Respirator a,bAs directedby the facilitysafety officerNon-zoonoticAgentNonerecommendedunless for foot<strong>and</strong>-mouthdiseaseAs directedby the facilitysafety officerProtectiveclothing aImpermeableto liquids;considerbased on heatsituationAs directedby the facilitysafety officerEye/hearing Gloves a Head/footprotection a protectionEyes: Full facepiecerespirator orindirectly ventedgoggles; contactlenses should notbe worn undergoggles or safetyglasses; considerprescription safetygogglesHearing: Considerdisposable earplugs if necessaryAs directed by thefacility safety officerGloves: Heavyduty (15–18mil) chemicalresistant glovesthat can bedisinfected ordisposedAs directed bythe facility safetyofficerFeet: Forworkersh<strong>and</strong>lingcarcasses, steeltoe/steelshankwaterproofboots; forothers, steel-toework shoes orbootsHead: Hard hatAs directedby the facilitysafety officeraSee www.safetyequipment.org for a list of vendors from OSHAbFor information on a full respiratory protection program, see www.osha/gov/SLTC/respiratoryprotection/index.cRegulations governing use of personal protective equipment in hazardous waste operations can be found at 29 CFR 1910.134<strong>and</strong> 29 CFR 1910.156 <strong>and</strong> are summarized in the “General Considerations” chapter of this guide.226

Diseases of concernViruses <strong>and</strong> non-spore-forming bacteria:Viruses <strong>and</strong> non-spore-forming bacteriaare temperature susceptible. For viruses suchas foot-<strong>and</strong>-mouth disease (FMD), precautionsmust be taken to prevent transmission ofairborne pathogens. Non-spore-forming bacteriawill be inactivated at continuous renderingtemperatures.Diseases for which rendering is an appropriatedisposal option include African swinefever, highly pathogenic avian influenza, contagiousbovine pleuropneumonia, brucellosis(B. melitensis, B. abortus, <strong>and</strong> B. suis), FMD,gl<strong>and</strong>ers, Japanese encephalitis, Q fever, RiftValley fever, rinderpest, classical swine fever,tularemia, <strong>and</strong> vesicular stomatitis.Spore-forming bacteria: Spore-formingbacteria are temperature susceptible. Those thatare not destroyed can persist in the environmentfor long periods.If it is not possible to render these carcassesimmediately, they must remain intact tokeep the spores from spreading to the externalenvironment. The spore-forming bacteria willbe inactivated <strong>and</strong> controlled if the uncut carcassesare properly rendered using the continuousmethod.Diseases of concern include anthrax.Prions: Prions (TSEs) are temperatureresistant. Extremely high temperatures (morethan 1,830 °F or 1,000 °C) for at least 15minutes are needed to destroy prion-infectedcarcasses. The best method for destroyingprion-infected animal carcasses is fixed-facilityburning or alkaline hydrolysis. Rendering isnot an appropriate method of deactivationfor prion-infected animal carcasses.Diseases include bovine spongiformencephalopathy, chronic wasting disease, <strong>and</strong>scrapie.227

SafetyOnce the safety of the rendered materialhas been established, the material may then beNotes on safetyHeat stress: See the guidelines on heatstress in the Safety section of the “GeneralConsiderations” chapter of this guide.First aid: First aid should be available toemployees at all times.Safety observers: Moving heavy equipmentis dangerous. Use a safety observer withthe authority to stop <strong>and</strong> correct unsafe conditionsor operations.Physical hazards: Grinders, crushers,Renderingburied, incinerated, composted, or applied asfertilizer.<strong>and</strong> cookers are used in rendering operations.Use care when near this dangerous equipment.Watch for loose or dangling clothing,equipment, or hair when working around thisequipment; use a safety observer.Ventilation: Although rendering equipmentuses enclosed pressure vessels, the areasurrounding the vessel should be adequatelyventilated.228

BiosecurityThe facility or facilities accepting contaminatedmaterials may be fixed-site facilitieslocated on heavily trafficked public orprivate property; they will probably be onsecondary streets next to major highways. Themovement of animal materials contaminatedwith non-zoonotic organisms (those that donot transmit diseases from animals to people)onto these sites should be planned very carefully.Although moving carcasses contaminatedwith non-zoonotic materials does not presenta health hazard to the public, a significant effortmust go into public awareness <strong>and</strong> publicrelations activities well before any carcassesare moved to the site.A rendering plant should process 60 to 70tons of carcasses per day, assuming 20 workinghours per day to justify the processingcosts. Do not use such facilities to dispose ofRenderinglarge volumes of carcasses contaminated withzoonotic agents; do not use them at all fordestroying TSE-contaminated carcasses.When h<strong>and</strong>ling infected animal materials,the rendering facility must discontinue allother operations in order to treat only the carcassesinfected with hazardous agents. Continuousrendering rather than batch renderingshould be used for the entire shipment ofanimal carcasses. This will prevent the vapors<strong>and</strong> materials generated during the renderingprocess from becoming airborne <strong>and</strong> spreadingto the environment.The rendering facility should have securitymeasures in place to monitor <strong>and</strong> excludeanimals <strong>and</strong> unauthorized personnel.Allow no one to move between the twoareas without thorough cleaning <strong>and</strong> disinfection.Do not allow equipment to move betweenthe sides.229

BiosecurityThe air flowing through the plant must bedirected from the finished side through to thereceiving side.Trucks being used to haul away the finishedproduct may not come into contact withRenderingthe receiving side or any vehicles containinghazardous materials. Vehicles <strong>and</strong> personnelmust be decontaminated before the vehiclesleave the disposal site.230

Environmental ImpactsRenderingGroundwater pollutionAlthough discharge of effluent into apublic sewer system <strong>and</strong> not into groundwateris anticipated, close coordination with State<strong>and</strong> local health <strong>and</strong> public works authoritiesis essential before any effluent can be releasedinto a public sewer system.Soil pollutionSome products of the rendering processmay not be acceptable for further use. Suchmaterial can likely be disposed of in l<strong>and</strong>fillsas solid waste according to State <strong>and</strong> localsolid waste regulations.Continuously operating rendering facilitiesare nearly always fixed on site <strong>and</strong> will havecoordinated with local health <strong>and</strong> public worksauthorities concerning releases. Before anydischarge, confirm with the facility officialsthat all of the necessary permits are in place.Soil pollution is not a concern unless thecarcasses are allowed to accumulate on thesurrounding grounds faster than the facility’sprocessing rate. Unprotected decomposing carcassesare a source of disease for people <strong>and</strong>animals <strong>and</strong> can pollute soil <strong>and</strong> surface water.Do not allow the carcasses to accumulateat a rate faster than that which the facility canprocess. Piled carcasses outside the facilitycreate a public awareness issue <strong>and</strong> can createhuman <strong>and</strong> animal health problems fromdisease vectors drawn to the carcasses. Decomposingcarcasses also create an air qualityissue.231

Environmental ImpactsRenderingSome onsite workers may need personalprotective equipment to minimize their exposureto airborne or aerosolized agents. Formore information, see the Safety section ofthis chapter.Air pollutionAir emissions containing chemicalswith unpleasant odors should be controlledat levels well below the odor threshold forchemicals of concern. Rendering facilitiesshould have air emissions programs in placeDepending on the pathogen involved,there may be a stigma attached to the renderedproducts that makes them unacceptable forfurther use.that comply with all Federal, State, <strong>and</strong> localregulations. Therefore, air emissions from therendering process should be of minimal concernto outside personnel managing recoveryoperations from a catastrophic event.232

CostThe costs of rendering follow the generalspecifications in the Cost section of the “GeneralConsiderations” chapter. Figure 3 showsthe components of the direct <strong>and</strong> indirectcosts of rendering.Table 3 lists direct variable costs for renderingcarcasses. For indirect cost items, seethe “General Considerations” chapter of thisguide.RenderingFigure 3. Components of direct <strong>and</strong>indirect costs for rendering operations.LaborInterest rateEnvironmentalimpactsMachineryDepreciationOthersL<strong>and</strong>fillTransportationStoragePermitting fee233

CostRenderingTable 3. Estimates of direct variable cost items for rendering animal carcasses.CattleCalvesWeanedhogsPreweanedhogsOthers (sheep,lambs, goats)Estimated average variable cost per carcassLabor $11.38 $4.04 $2.02 $0.09 $1.17Equipment $27.28 $9.68 $9.49 $0.61 $8.44L<strong>and</strong>fill cost of disposing of residual $2.69 $0.95 $0.48 $0.02 $0.28Permitting n/a n/a n/a n/a n/aTransportation n/a n/a n/a n/a n/aAverage variable cost per mortality$41.35 $14.67 $11.99 $0.72 $9.89Estimated average cost per tonLabor $30.35 $30.35 $30.35 $30.35 $30.35Equipment $72.75 $72.75 $142.32 $204.15 $219.33L<strong>and</strong>fill cost of disposing of residual $7.16 $7.16 $7.16 $7.16 $7.16Permitting n/a n/a n/a n/a n/aTransportation n/a n/a n/a n/a n/aAverage variable cost per ton $110.26 $110.26 $179.83 $241.66 $256.84Source: Livestock mortality <strong>and</strong> burial cost in 2002 by Sparks Companies, cited in the National Agricultural Biosecurity CenterConsortium for Carcass Disposal (NABCCD) Working Group report234

Figure 4. Formulas to estimate the direct variable cost relating to rendering.If the hourly labor <strong>and</strong> equipment costs are $10 <strong>and</strong> $25, respectively, use these formulas toestimate the direct variable cost (DVC):• By number of carcasses:DVC = 41.35Q cattle+ 14.67Q calves+ 11.99Q weaned hogs+ 0.72Q preweaned hogs+ 9.89Q othersWhere Q iis the total number of carcasses in animal category i.• By weight:DVC = 110.26W cattle+ 110.26W calves+ 179.83W weaned hogs+ 241.66W preweaned hogs+ 256.84W othersWhere W iis the total weight in tons of animal category i.(Figure continued on next page)235

CostRenderingFigure 4. (Continued)If the hourly labor <strong>and</strong> equipment costs are C L<strong>and</strong> C E, rather than $10 <strong>and</strong> $35 respectively,use these formulas to estimate the direct variable cost (DVC):• By number of carcasses:DVC = (1.14C L+ 0.78C E+ 2.69)Q cattle+ (0.40C L+ 0.28C E+ 0.95)Q calves+ (0.20C L+ 0.27C E+0.48)Q weaned hogs+ (0.01C L+ 0.02C E+ 0.02)Q preweaned hogs+ (0.12C L+ 0.24C E+ 0.28)Q othersWhere Q iis the total number of carcasses in animal category i.• By weight:DVC = (3.04C L+ 2.08C E+ 7.16)W cattle+ (3.04C L+ 2.08C E+ 7.16)W calves+ (3.04C L+ 4.07C E+7.16)W weaned hogs+ (3.04C L+ 5.83C E+ 7.16)W preweaned hogs+ (3.04C L+ 6.27C E+ 7.16)W othersWhere W iis the total weight in tons of animal category i.Besides the labor, equipment, <strong>and</strong> l<strong>and</strong>fillcosts of disposing residuals, the variabledisposal cost includes transportation costs <strong>and</strong>permitting fees.236

Alkaline hydrolysisSummaryDefinition <strong>and</strong> objectivesAlkaline hydrolysis of carcasses is a processby which heat <strong>and</strong> pressure dissolve <strong>and</strong>sterilize animal carcasses in a strong solutionof sodium or potassium hydroxide. An alkalinehydrolysis system can completely decontaminateinfected tissue.The objectives of alkaline hydrolysis are to:• Inactivate pathogens <strong>and</strong> prions such astransmissible spongiform encephalopathy(TSE)• Convert dead animals into a sterilesolution or dried material that has lesspotential for environmental pollutionthan before treatmentThe ultimate goal of the alkaline hydrolysisprocess is to convert animal carcasses intoenvironmentally safe materials while avoidingnegative public perception.This system costs less to operate than doother carcass disposal methods such as incineration.The mechanical components of thisprocess are highly durable.Alkaline hydrolysis can occur in fixed ormobile facilities. When choosing betweenthese two types of facility for disposing ofanimal carcasses, several factors should beconsidered, including cost, transportation,agent suitability, environmental risk, disposalcapacity, procedure speed, <strong>and</strong> the availabilityof resources (Table 1).237

Alkaline hydrolysisSummaryTable 1. Considerations for choosing an alkaline hydrolysis system.Consideration Fixed alkaline hydrolysis Mobile alkaline hydrolysisApplication <strong>Animal</strong> <strong>Animal</strong>Transportation concerns Yes NoAgents inactivated Viruses, bacteria <strong>and</strong> TSE 3 Viruses, bacteria <strong>and</strong> TSE 3Disposal capacity 1 Low LowEnvironmental risk Low MediumRegulatory restrictions Low MediumCost 2Lower rent but higheroperation costHigher rent but loweroperation costAvailability of resources Low LowProcedure speed High High1<strong>Animal</strong> mortality (tons): Low < 100 tons < Medium < 300 tons < High2The initial investment of mobile alkaline hydrolysis is higher than that of fixed alkaline hydrolysisbecause of the higher rent cost of mobile facilities. However, the transportation cost of mobilealkaline hydrolysis is lower, thereby reducing the operation cost.3TSE = transmissible spongiform encephalopathyUnless specified, the descriptions on the next few pages apply to both fixed <strong>and</strong> mobile facilities(Figs. 1, 2, <strong>and</strong> 3).238

Figure 1. A tissue digester in a fixed alkaline hydrolysis facility. (Photocourtesy of Waste Reduction by Waste Reduction, Inc., Indiananapolis, IN)239239

Alkaline hydrolysisSummaryFigure 2. A carcass digester in a fixed alkaline hydrolysis facility. (Photocourtesy of Waste Reduction by Waste Reduction, Inc., Indiananapolis, IN)240

Figure 3. The crushable bone <strong>and</strong> teeth remaining from a carcassdigester in a fixed alkaline hydrolysis facility. (Photo courtesy of WasteReduction by Waste Reduction, Inc., Indiananapolis, IN)241241

Alkaline hydrolysisSummaryGeneral descriptionThe method of the alkaline hydrolysis processto treat carcasses depends on the kind ofcontamination:• To inactivate microbial pathogens, thecarcasses must be heated to 212 °F <strong>and</strong>pressurized at 15 pounds per square inchfor 3 hours.• To destroy TSE, including bovinespongiform encephalopathy, thecarcasses must be heated to 300 °F <strong>and</strong>pressurized at 70 pounds per square inchfor 6 to 8 hours.Alkaline hydrolysis processes occur inhot oil or in steam-jacketed, insulated, stainless-steelpressure vessels with automatic ormanual control systems. The process breakslarge molecules of organic matter into smallermolecules (amino acids, sugars, <strong>and</strong> fattyacids). Destroyed during this process are allpathogens, including the protein coats of theviruses, the peptide bonds of the prions, <strong>and</strong>vegetative <strong>and</strong> sporulated bacteria.The pH level of the treated material dropsfrom 14 at the beginning of the process toabout 11 at the end. The pH level at the end ofthe alkaline hydrolysis process highly dependson the total amount of operation time,the amount of fat in the carcass (a higher fatcontent can result in a lower pH), <strong>and</strong> otherfactors such as the buffering of the alkalinesolution by the carcass.The vessels used in the process may beequipped with devices to measure the weightsof the carcasses, water <strong>and</strong> alkali powder, <strong>and</strong> tomeasure <strong>and</strong> control the temperature, pH, pressure,<strong>and</strong> the amount of time needed for steril-242

ization. The mixed materials are agitated <strong>and</strong>heated consistently either by mechanical mixersor by steam <strong>and</strong> alkaline circulation systems.Containers are provided for the bone pieces<strong>and</strong> indigestible materials such as cellulose,latex, <strong>and</strong> metal, which are separated from thefinal effluent. The wetted parts of the digesterare stainless steel or a flouropolymer such asTeflon, which can tolerate high temperatures<strong>and</strong> strong acidic or alkaline solutions.Some materials are resistant to alkalinehydrolysis digestion, including bulk cellulose(such as paper, strings, undigested plantfiber, <strong>and</strong> wood shavings) <strong>and</strong> the inorganiccontent of the fecal matter associated with thecarcasses. However, the process completelysterilizes these indigestible materials.The carcass digestion process occurs ina completely sealed environment; very littlegas is emitted into the air. Odors are releasedfor a short period during carcass loading <strong>and</strong>unloading.The biochemical oxygen dem<strong>and</strong> (BOD)of the final effluent is very high because ofthe high concentrations of organic matter.The BOD may reach 0.58 to 0.83 pounds pergallon (70,000 to 100,000 milligrams perliter). It can be diluted by adding water ora low-BOD solution. It may be disposed ofinto the sewer system after local wastewatertreatment authorities have been consulted.The pH of the final liquid effluent shouldbe reduced to about 9 by adding carbon dioxideor industrial acid (such as acetic acid)before l<strong>and</strong> application.Because the mobile alkaline hydrolysisunits do not require that the carcasses betransported, the disposal process is considerablyfaster than for fixed facilities. However,it may not be possible to deploy these unitsinto the field quickly for massive amounts ofanimal carcasses.243243

Regulatory SynopsisAlkaline hydrolysisCoordination <strong>and</strong> jurisdictional considerationsThe decision to use alkaline hydrolysisas a carcass disposal option should be madejointly by the members of the incident comm<strong>and</strong>structure established by local or stateauthorities.Alkaline hydrolysis should be undertakenonly with explicit approval by the institutions<strong>and</strong> agencies that are competent in makingdeterminations about protecting the environment.States have ranked preferred methods forcarcass disposal, <strong>and</strong> the incident comm<strong>and</strong>structure must use the preferred options beforeundertaking alkaline hydrolysis activities.If the carcasses are to be transported tonearby counties for alkaline hydrolysis, theincident comm<strong>and</strong> structure must considerthe added problems of transportation safety<strong>and</strong> contamination of other property. Localauthorities should have an inter-county memor<strong>and</strong>umof underst<strong>and</strong>ing in place so thatthe carcasses can be easily transported to thenearest facility for alkaline hydrolysis.244

Pollution <strong>and</strong> other property damage considerationsThe exercise of police power gives governmentalentities <strong>and</strong> agencies wide discretionin making decisions about carcass disposalto protect public health. However, theexercise of this power does not shield governmentalentities against nuisance actions if theproper precautions are not taken.The two main problems with alkalinehydrolysis are waste <strong>and</strong> odor, both of whichcould trigger nuisance or other kinds oflawsuits. Sovereign immunity may not be adefense to such an action.The decision to use alkaline hydrolysismust be made by the appropriate technicalgroup within the incident comm<strong>and</strong> structurebecause injury to people or property couldprompt suits similar to those based on nuisance.245245

PlanningPlanning considerationsAlkaline hydrolysisTo operate successfully, alkaline hydrolysisunits require more skill <strong>and</strong> expertise th<strong>and</strong>o some of the other disposal methods, suchas burial. At least two technicians per shiftfor each alkaline hydrolysis system must betrained <strong>and</strong> equipped for operation, safety, <strong>and</strong>biosecurity.The personnel must be trained in safe h<strong>and</strong>lingof the animal carcasses, prevention ofcross contamination, processing procedures,<strong>and</strong> decontamination of the equipment <strong>and</strong> thesite during <strong>and</strong> after processing.Issues that must be considered includethose related to h<strong>and</strong>ling, packing, <strong>and</strong> storingthe carcasses as well as conveying them tothe alkaline hydrolysis (mainly fixed alkalinehydrolysis) site. For more information, see theTransportation section of the “General Considerations”chapter of this guide.Provide the appropriate amounts of sodiumor potassium alkaline materials at about10 percent of the carcass weight if it is indried form or 20 percent of the carcass weightif it is in liquid form. If potassium hydroxideis used, the fertilizer value of the effluent willincrease for l<strong>and</strong> use.Make sure that the vessels in the alkalinehydrolysis units can tolerate pressures ofup to 100 pounds per square inch as recommendedby the American Society of MechanicalEngineers. TSE-infected carcasses need avessel pressure of no more than 70 pounds persquare inch. Failure to comply with this rulemay result in serious injury or death.Provide diesel fuel for electricity generation<strong>and</strong> propane for steam production. Gener-246

ally, 1 pound of steam is needed to sterilize1 pound of carcass.Sufficient water must be provided for thealkaline hydrolysis process, for steam generation,<strong>and</strong> for the washing <strong>and</strong> rinsing processes.Additional clean water must be supplied forsafety as well as a contingency for spills of thecaustic solutions.Although soft water is needed to generatesteam from the boiler, clean water from lakes,ponds, <strong>and</strong> rivers may be used for washing,rinsing, <strong>and</strong> using carcass hydrolysis. Anysurface water may be used to dilute the finaleffluent. Table 2 shows the water consumption<strong>and</strong> final effluent production for alkalinehydrolysis of 1,000 pounds of carcasses.Additional energy will be required if youplan to dehydrate the final effluent, which maycontain up to 90 percent moisture. To minimizethe foaming problem during the dehydrationprocess, reduce the pH of the effluentto about 6 by adding acid or carbon dioxidebefore drying it.The dried weight (inorganic <strong>and</strong> mineralcontent) of the final effluent is about 2 percentof the total carcass weight <strong>and</strong> can be used forl<strong>and</strong> application. Coordinate in advance <strong>and</strong>plan for the l<strong>and</strong> disposal of the final effluent<strong>and</strong> solids with county <strong>and</strong> State regulatoryagencies, USDA Natural Resources ConservationService, <strong>and</strong> university Extension agronomists.Plan to use the effluent directly as a substratein an anaerobic digester <strong>and</strong> the solids(mainly bone <strong>and</strong> teeth, which can easily becrushed into a fine powder) as nitrogen <strong>and</strong>mineral sources in compost, or dispose of theeffluent at a public l<strong>and</strong>fill.247247

ProceduresAlkaline hydrolysisTable 2. Capacities <strong>and</strong> dimensions for fixed alkaline hydrolysis <strong>and</strong> mobile alkalinehydrolysis systems.Alkaline hydrolysisoptionsFixed alkalinehydrolysisMobile alkalinehydrolysisCarcass digestion Minimum Water consumption for Effluent productioncapacity a installation area 1,000 lb of carcasses b for 1,000-lb carcasses2,000–10,000 lb/8 ha 1,000 ft 2 60–240 gal b 120–300 gal4,000 lbs/8 ha 300 ft 2 60–240 gal b 120–300 galaFor higher carcass capacities, it is better to use fixed <strong>and</strong> mobile alkaline hydrolysis units in a modular pattern rather than usingunits with higher capacities. This is because they can be operated sequentially; they use less energy <strong>and</strong> labor; <strong>and</strong> they are easierto manage than are larger units.bWater consumption will be minimized if the alkaline hydrolysis systems use more alkali <strong>and</strong> have a longer period of time forhydrolysis, <strong>and</strong> if the carcasses are shredded instead of intact <strong>and</strong> contain a highly agitated mixture of materials. More water isrequired for inactivating carcasses infected with TSE than for those infected with bacteria.248

Fixed alkaline hydrolysis proceduresFollow the operator’s manual for fixedalkaline hydrolysis systems. Assign twotrained operators per shift, one to control <strong>and</strong>manage the carcass feeding, processing, <strong>and</strong>off-loading; the other to manage the boiler,generators, <strong>and</strong> the alkaline <strong>and</strong> water storagesystems.Operate the entire system for at least 1hour without feeding in any carcass materialsto ensure the proper <strong>and</strong> smooth operation ofthe processing equipment, including the steamgenerator, digester, mixer or circulation pump,<strong>and</strong> controlling devices.For proper operation of a fixed alkalinehydrolysis system, make sure that the followingprocesses occur in this order:1. The carcasses are loaded into the hopperof the fixed alkaline hydrolysissystem <strong>and</strong> their weights are measuredby the built-in load cells.2. The carcasses are fed into the vessel.3. The feeders of the different materialsadd the required amount of alkalinesolution <strong>and</strong> water to the vessel.4. The vessels are properly sealed, <strong>and</strong>the heating process occurs in a completelyenclosed environment.5. The final effluent is tested for temperature,pH, <strong>and</strong> suspended solids beforedisposal.Follow local <strong>and</strong> Federal guidelines, <strong>and</strong>adjust the pH, temperature, <strong>and</strong> biologicaloxygen dem<strong>and</strong> of the solution.Fixed alkaline hydrolysis units operate athigh pressure. The equipment must be designed,maintained, <strong>and</strong> used in strict accordancewith industrial <strong>and</strong> State guidelines.Failure to do so may result in an explosion,causing serious injury or death.249249

ProceduresAlkaline hydrolysisMobile alkaline hydrolysis proceduresAssign skilled drivers with the appropriatedriving permits to maneuver the mobilealkaline hydrolysis units. These drivers are inaddition to the technicians required to managethe mobile alkaline hydrolysis process.Plan to provide up to two truck trailers<strong>and</strong> an adjunct truck/feeder for mobile alkalinehydrolysis. The first trailer is for mountingthe grinder <strong>and</strong> cooker/conveyor; thesecond is for an oil heater or steam generatorsalong with a feed conveyor system. Thetruck/feeder carries an alkaline supply system.Truck containers will also be needed to collect<strong>and</strong> transport the final effluent to a disposalsite.Propane <strong>and</strong> water tanks will be neededfor a 400-horsepower on-site steam generator.Equip the mobile alkaline hydrolysis with anelectric generator of sufficient horsepower toprovide electricity for various functions of theunit <strong>and</strong> for illumination.Store the final effluent in a containerequipped with a heating system to preventfreezing during winter. To dispose of the endproduct, follow the procedures outlined in thefixed alkaline hydrolysis section of this guide.250

Figure 4. Schematic of a mobile alkaline hydrolysis system with two auxiliary trucks.(Photo courtesy of Waste Reduction by Waste Reduction, Inc., Indiananapolis, IN)251251

ProceduresAlkaline hydrolysisFigure 5. Schematic of a mobile alkaline hydrolysis system with the maincomponents of high capacity of 0.5 x 10 6 pounds per 8 hours. (Photo courtesyof Waste Reduction by Waste Reduction, Inc., Indiananapolis, IN)Auxiliary openingDigesterFeed hopperFeed augerCraneShredderLockersControlsElectric generatorSteam generatorDiesel fuel tank252

Figure 6. A mobile alkaline hydrolysis unit. (Photo courtesyof Waste Reduction by Waste Reduction, Inc., Indiananapolis, IN)253253

SafetyAlkaline hydrolysisTable 3. Personal protective equiment guidelines for alkaline hydrolysis.254Natureof workDirecth<strong>and</strong>ling ofcontaminatedmaterialNo directh<strong>and</strong>ling ofcontaminatedmaterial, butpotentially incontact withcaustic chemicalsMask/Respirator a,b, cZoonoticagentDisposableparticulaterespirator(N95, N99, orN100); half orfull facepieceNonerecommendedNon-zoonoticagentNonerecommendedunless for foot<strong>and</strong>-mouthdiseaseNonerecommendedProtectiveclothing aImpermeableto caustic liquids(such as DupontTychem ® QC);consider basedon heat situationOvergarmentimpermeable tocaustic liquids(such as DupontTychem ® QC)Eye/hearing Gloves a Head/footprotection a protectionEyes: Full facepiecerespirator orindirectly ventedgoggles; contactlenses should notbe worn undergoggles or safetyglasses; considerprescription safetygoggles; face shieldunless wearing a fullfacepiece respiratorEyes: Splash-proof,indirectly ventedgoggles; face shieldGloves: Heavyduty (15–18mil) chemicalresistantgloves thatcan bedisinfected ordisposedSame asaboveFeet: For workersh<strong>and</strong>ling carcasses,steel-toe/steelshank waterproofboots; for others,steel-toe workshoes or bootsHead: Hard hatFeet: Steel-toework shoes orbootsHead: Hard hataSee www.safetyequipment.org for a list of vendors from OSHAbFor information on a full respiratory protection program, see www.osha/gov/SLTC/respiratoryprotection/index.cRegulations governing use of personal protective equipment in hazardous waste operations can be found at 29 CFR 1910.134 <strong>and</strong> 29 CFR1910.156 <strong>and</strong> are summarized in the “General Considerations” chapter of this guide.

Diseases of concernViruses <strong>and</strong> non-spore-forming bacteria:Alkaline hydrolysis is an effectivemethod for eliminating viral <strong>and</strong> non-sporeformingbacteria.Precautions must be taken to prevent inhalationof airborne pathogens. Personal protectiveequipment is essential for worker safetywhile the carcasses are being transported <strong>and</strong>h<strong>and</strong>led on site.Diseases for which alkaline hydrolysisprocesses are appropriate include highlypathogenic avian influenza, contagious bovinepleuropneumonia, brucellosis, foot-<strong>and</strong>-mouthdisease, gl<strong>and</strong>ers, Japanese encephalitis, Qfever, Rift Valley fever, rinderpest, Africanswine fever, classical swine fever, tularemia,<strong>and</strong> vesicular stomatitis.Spore-forming bacteria: Alkaline hydrolysisis an effective method of disposal tocontrol the spread of spore-forming bacteria.Diseases of concern include anthrax.Prions (TSEs): Alkaline hydrolysis is aneffective method of disposal; however, materialsuspected of being contaminated withTSEs should be digested for no less than 6hours.Diseases include bovine spongiformencephalopathy, chronic wasting disease, <strong>and</strong>scrapie.255255

SafetyNotes on safetyHeat stress: See guidelines on heat stressin the Safety section of the “General Considerations”chapter of this guide.First aid: First aid should be available toemployees at all times.Safety observers: It is dangerous tomove contaminated plant <strong>and</strong> animal materialsaround large volumes of heated sodiumhydroxide; use a safety observer.Chemical hazards: Provide safety showers<strong>and</strong> emergency eyewash stations within 20feet of each alkaline hydrolysis unit; causticchemical burns are exceptionally hazardous<strong>and</strong> can cause irreparable damage to the eyeswithin seconds if not removed using copiousAlkaline hydrolysisamounts of water for at least 15 minutes.Workers exposed to any amount of sodiumhydroxide in their eyes should use the eyewashstation <strong>and</strong> report to an emergencyroom.Ventilation: Although alkaline hydrolysisreactors use enclosed pressure vessels, thearea surrounding the vessel should be adequatelyventilated.Pressure vessels: Alkaline hydrolysispressure vessels operate under high pressure<strong>and</strong> temperature. The risk of injury resultingfrom failure of a vessel is significant; followall manufacturer directions carefully.256

BiosecurityGroundwater pollutionFacilities accepting contaminated materialmay be fixed sites on heavily trafficked publicor private property (such as a universitycampus). Moving non-zoonotic-contaminatedplant or animal materials onto these sitesshould be planned carefully.Although the movement of carcassescontaminated with non-zoonotic materialsdoes not present a human health hazard, asignificant effort must go into public awareness<strong>and</strong> public relations activities well beforemoving any carcasses to the site. Such facilitiesshould not be used for disposal of largeamounts of carcasses contaminated withAlkaline hydrolysiszoonotic agents or TSEs.Vehicles <strong>and</strong> personnel must be decontaminatedbefore the vehicles leave the disposalsite. See additional material in the Safety <strong>and</strong>Biosecurity section of the “General Considerations”chapter of this guide.If performed according to this guide,releasing effluent poses no threat to publichealth; however, a public relations planshould be in place before disposing of anyeffluent in a public sewer system. Disposalshould be performed fully in conjunction withstate <strong>and</strong> local health department authorities.257

Environmental Impacts Alkaline hydrolysisControl of effluent dischargeClose coordination with state <strong>and</strong> localhealth <strong>and</strong> public works authorities is essentialbefore any effluent is released into apublic sewer system.Effluent should be tested <strong>and</strong> monitoredbefore release into a sewage system. A pHrange of 10.0 to 11.5 is generally acceptablethroughout the United States but may vary byjurisdiction. Effluent must be released at orabove 374 °F (190 °C) to ensure that the effluentwill not solidify.Soil pollutionAlkaline hydrolysis poses no soil pollutionconcerns unless the effluent disposal isnot controlled.Some tissue, such as bone <strong>and</strong> teeth, willremain after the alkaline hydrolysis processis complete. This material can be ground<strong>and</strong> disposed of in l<strong>and</strong>fills as solid waste inaccordance with State <strong>and</strong> local solid wasteregulations.All waste will be monitored <strong>and</strong> testedbefore shipment of potentially dangerousmaterials.258

Air pollutionThere are no notable emissions associatedwith alkaline hydrolysis. Gas release isnot significant either as a health hazard to thepublic or as a nuisance gas.Air pollution concerns are limited to theon-site workers, who will need personal protectiveequipment to minimize their exposureto the airborne or aerosolized agents.259259

CostCosts <strong>and</strong> issuesThe cost breakdown relating to alkalinehydrolysis follows the general specificationsfrom the “General Considerations” chapter ofthis guide.The direct cost consists of fixed cost,including depreciation <strong>and</strong> financing costs,<strong>and</strong> variable costs for the use of labor, alkali,steam, sewer disposal, electricity, l<strong>and</strong>fill materials,transport, maintenance, <strong>and</strong> repair.The direct fixed cost <strong>and</strong> the variablecosts depend on the facility’s capacity (Tables4–6). For specific indirect cost items, seethe “General Considerations” chapter of thisguide.Alkaline hydrolysisTable 4. Initial investment <strong>and</strong> directfixed cost estimates for a tissue digester with2,000-pound capacity per cycle.Initial investment aInvestment(2,000-lb digestercapacity: 0.25 ton/hr)Digester unit $400,000Installation cost $200,000Remodel sampling rooms$225,000<strong>and</strong> redirect pipesDehydration <strong>and</strong> odor$300,000control systemTotal $1,125,000Fixed annual costDepreciation (20 years) $56,250Interest (6%) $67,500Total $123,750aSource: http://www.co.larimer.co.us/boards/minutes/Aug03Min.htm. There is no initial investment breakdownfor a 10,000-pound digester.260

Table 5. Estimates of direct variable costs by weight <strong>and</strong> mortality for a 2,000-pounddigester.2,000-lb equipmentCost per ton Cattle Calves Weaned hogsPreweanedhogsOthers(sheep, lambs,goats)Average weight per mortality (lb) 750 266 133 6 77Alkali $49.50 18.56 6.58 3.29 0.15 1.91Electricity $1.00 0.38 0.13 0.07 0.00 0.04Water $1.84 0.69 0.24 0.12 0.01 0.07Steam $20.40 7.65 2.71 1.36 0.06 0.79Sewer $1.65 0.62 0.22 0.11 0.00 0.06L<strong>and</strong>fill $1.09 0.41 0.14 0.07 0.00 0.04Repairs <strong>and</strong> $40.00 15.00 5.32 2.66 0.12 1.54maintenanceLabor $22.00 8.25 2.93 1.46 0.07 0.85Transportation n/a n/a n/a n/a n/a n/aVariable cost $137.48per tonVariable cost per carcass $51.56 $18.27 $9.14 $0.41 $5.30Source: http://www.wr2.net/sales/cost_calculator.html261261

CostAlkaline hydrolysisTable 6. Estimates of direct variable costs by weight <strong>and</strong> carcass for a 10,000-pounddigester.10,000-lb equipmentCost per ton Cattle Calves Weaned hogsPreweanedhogsOthers(sheep, lambs,goats)Average weight per carcass (lb) 750 266 133 6 77Alkali $49.50 18.56 6.58 2.99 0.15 1.91Electricity $1.00 0.38 0.13 0.07 0.00 0.04Water $1.84 0.69 0.24 0.12 0.01 0.07Steam $20.40 7.65 2.71 1.36 0.06 0.79Sewer $1.65 0.62 0.22 0.11 0.00 0.06L<strong>and</strong>fill $1.09 0.41 0.14 0.07 0.00 0.04Repairs <strong>and</strong> $40.00 15.00 5.32 2.66 0.12 1.54maintenanceLabor $0.92 0.34 0.12 0.06 0.00 0.04Transportation n/a n/a n/a n/a n/a n/aVariable cost $116.40per tonVariable cost per carcass $43.65 $15.46 $7.44 $0.34 $4.49Source: http://www.wr2.net/sales/cost_calculator.html262

Figure 7. Formulas to estimate the direct variable cost relating to alkaline hydrolysis.The direct variable cost (DVC) using a tissue digester with a 2,000-pound capacity:• By number of carcasses:DVC = 51.56Q cattle+ 18.27Q calves+ 9.14Q weaned hogs+ 0.41Q preweaned hogs+ 5.30Q othersWhere Q iis the total mortality of animal category i.• By weight:DVC = 137.48(W cattle+ W calves+ W weaned hogs+ W preweaned hogs+ W others)Where W iis the total weight in tons of animal category i.(Figure continued on next page)263263

CostAlkaline hydrolysisFigure 7. (Continued)The direct variable cost (DVC) using a tissue digester with a 2,000-pound capacity:• By number of carcasses:DVC = 43.65Q cattle+ 15.46Q calves+ 7.44Q weaned hogs+ 0.34Q preweaned hogs+ 4.49Q othersWhere Q iis the total mortality of animal category i.• By weight:DVC = 116.40(W cattle+ W calves+ W weaned hogs+ W preweaned hogs+ W others)Where W iis the total weight in tons of animal category i.264

DigestionDefinition <strong>and</strong> objectivesDigestion is a process that effectively preservescarcass materials under acidic conditions(using lactic or phosphoric acid) or usesfermentative bacteria to convert the materialsto a mixture of primarily methane, carbondioxide <strong>and</strong> water.The objectives of digestion methods areto:• Provide long-term storage for animalcarcasses using acid preservation• Prevent the growth of disease-causingmicroorganisms• Anaerobically digest animal carcassesSummary<strong>and</strong> produce methane for energy generationThe ultimate goal of carcass digestionprocesses is either to preserve carcass materialsunder acidic conditions or to convert themto valuable products without creating healthhazards or negative environmental impacts.Three processes are used widely to digestcarcasses: lactic acid fermentation, phosphoricacid preservation, <strong>and</strong> carcass biogasproduction. Some organic acids, such asacetic, formic, <strong>and</strong> propionic acids, are usedto simply preserve the carcasses.265

DigestionSummaryTable 1. Methods considerations for the digestion of contaminated animals.Consideration Lactic acid fermentation Phosphoric acidpreservationCarcass biogas productionTransportation concerns No Yes YesAgents inactivatedViruses <strong>and</strong> bacteria(except TSE 4 )Viruses <strong>and</strong> bacteria(except TSE 4 )Viruses <strong>and</strong> bacteria(Except TSE 4 )Disposal capacity 1 Low Low LowPotential forLow Low Mediumenvironmental impactRegulatory restrictions 2 Low Low MediumCost 3 Medium Low HighAvailability of resources Low Low LowProcedure speed Medium High Low1<strong>Animal</strong> carcasses (tons): Low = < 100 t; Medium = 100–300 t; High = > 300 t2The stringency of restrictions imposed by federal, state, <strong>and</strong> local agencies3Cost estimate (per ton): Low = < $200; Medium = $200–800; High = > $8004TSE = transmissible spongiform encephalopathy(Cutoff points may vary, depending on such factors as transportation, carcass load, animals affected, disposal facility, <strong>and</strong> level ofsecurity.)266

The carcasses of several kinds of animals—cattle,swine, poultry, sheep, goats,fish, <strong>and</strong> wild birds—can be treated in thelactic acid fermentation, phosphoric acidpreservation, <strong>and</strong> carcass biogas productionsystems. However, none of these options caninactivate abnormal proteins (prions).In the lactic acid fermentation process,lactic acid bacteria are added to ground carcassesmixed with fermentable carbohydratesto produce lactic acid under anaerobic conditions.These bacteria may produce volatileacids, hydrogen peroxide, <strong>and</strong> antibiotic-likecompounds that inhibit many bacteria.In the phosphoric acid preservationprocess, phosphoric acid is added directlyto ground or small pieces of carcasses. Thephosphoric acid disrupts the membrane functionsof the microorganisms, reducing theirdisease-causing activity.Lactic acid fermentation <strong>and</strong> phosphoricacid preservation are called minor digestion orstabilization processes. They cause little noticeablechange in protein structure, whereascarcass biogas production changes the proteinmaterials considerably.Lactic acid fermentation <strong>and</strong> phosphoricacid preservation not only destroy or inactivatemost disease-causing microorganisms,but also create an acidic pH that picklesthe carcass materials, enabling them to bepreserved safely for up to 4 months if theyremain immersed at the proper chemical concentrations.Carcass pickling is used for decontamination<strong>and</strong> long-term storage of dead poultry.Most rendering companies accept carcassespickled in acid because they are ready forcooking <strong>and</strong> meal production.Compared to cold storage, lactic acidfermentation costs less to preserve ground <strong>and</strong>homogenized poultry carcasses <strong>and</strong> transportthem to rendering facilities. However, in lacticacid fermentation, the costs of the additives267267

Digestioncannot be recovered with any feed ingredientproduced. Inoculants may include a fermentablecarbohydrate such as sucrose, molasses,whey, or ground corn added to the groundcarcasses.In contrast, the cost of the added phosphoricacid in the phosphoric acid preservationprocess can be recovered as a nutritionalphosphorus source in the feed ingredientsproduced from the materials preserved.Lactic acid fermentation <strong>and</strong> phosphoricacid preservation eliminate the need forrenderers to pick up the carcasses every day;they reduce the biosecurity risks <strong>and</strong> costs byreducing the number of farm visits. Transportingacid-preserved carcass materials has lesspotential to transmit disease than does transporting“fresh” carcasses.After 30 days at 80 °F, lactic acid digestionof poultry carcasses produces about 4 to 5Summarypercent lactic acid, 0.2 percent acetic acid, 0.2percent ethanol, <strong>and</strong> 0.2 to 0.3 percent ammonia-nitrogen.The treated materials maintain acomposition of 63 to 67 percent water, 11 to14 percent protein, 13 to 14 percent fat, <strong>and</strong> 2to 3 percent ash, which is similar to the compositionof the original materials.At concentrations of more than 3 percentlactic acid or 6 percent phosphoric acid,many pathogens such as Salmonella spp.,Campylobacter jejuni, fecal coliforms, <strong>and</strong>streptococci are destroyed in poultry offal <strong>and</strong>carcasses. Lactic acid also reduces the amountof fungi in broiler carcasses <strong>and</strong> offal.Some factors make it difficult <strong>and</strong> expensiveto control the biological process in lacticacid fermentation <strong>and</strong> carcass biogas production.For example, carcasses have higher nitrogencontent than do most wastes, which resultsin high ammonia concentrations that can268

inhibit the anaerobic digestion of the carcasswastes. Under controlled conditions, fermentationfailures occur 10 percent of the time.For carcass biogas production, the operationalcost of using mesophilic organisms(those that are active at 95 to 100 °F) is lessthan that for thermophilic organisms (thoseactive at 131 °F). Mesophilic organismsrequire 15 to 30 days of retention time forpathogen inactivation; thermophilic organismsrequire 12 to 14 days.The thermophilic fermentors used incarcass biogas production are better than themesophilic fermentors at reducing to acceptablelevels the coliform bacteria, insect eggs,<strong>and</strong> internal parasites in the carcass material.However, they may not destroy some pathogensor temperature-resistant bacteria such asBacillus cereus associated with carcasses. Thisis why additional heat treatment is required tofully inactivate the pathogenic agents that cansurvive carcass biogas production.Carcass biogas production considerablyreduces the chemical <strong>and</strong> biological oxygendem<strong>and</strong>, total solids, <strong>and</strong> volatile solids of thematerials. The remaining materials, generallyamino <strong>and</strong> fatty acids, can be used for composting.When treated by an anaerobic digester, thesludge or semisolid biowaste such as groundcarcasses mixed with manure can yield 8 to11 cubic feet of methane per pound (0.5 to0.67 cubic meter per kilogram) of volatilesolids removed by the process.Carcass biogas production is a multi-stepprocess (Fig. 1):1. Hydrolysis: The biopolymers (carbohydrates,fats <strong>and</strong> proteins) of theanimal matter are broken down intosmaller, soluble molecules.2. Fermentation: The products of Step 1are converted into organic acids (mainlyacetic), volatile fatty acids, carbondioxide, <strong>and</strong> hydrogen.269269

Digestion3. Acetogenesis: The volatile fatty acidsare converted to acetic acid, carbondioxide, <strong>and</strong> hydrogen.4. Methanogenesis: The acetate <strong>and</strong>ethanol compounds are converted tomethane <strong>and</strong> carbon dioxide.Several groups of bacteria perform eachof these steps in carcass biogas production.Some of these microorganisms (such as intestinalanaerobic lactic-acid-forming bacteria)are naturally available in manure <strong>and</strong> in theintestines of poultry <strong>and</strong> cattle. This is whyadding manure to the carcasses speeds thefermentation process <strong>and</strong> enriches the ratio ofcarbon to nitrogen to more than 20:1.The pH of the digester should range from6.8 to 7.5. Because the byproducts of the fatdegradation inhibit the methanogenic activity(because the pH is lowered), calcium carbonate<strong>and</strong> calcium hydroxide may need to beSummaryadded to maintain a near neutral pH <strong>and</strong> to precipitatelong-chain fatty acids (which are toxicto methanogenic bacteria) in the biodigester.Because domestic livestock <strong>and</strong> poultrycarcasses are composed of more than 50percent water, it is easier to use wet digestion,which has a higher efficiency than does drydigestion.Carcass biogas production systems areavailable in batch or continuous digesters.Three types of batch systems—single-stage,sequential-batch, <strong>and</strong> hybrid-batch—are usedfor biogas production.In the single-stage system, a pump recirculates<strong>and</strong> mixes its contents from the bottomto the top of the digester, <strong>and</strong> fermentationis allowed to continue until production ofthe gas stops. Once the digestion is completed(no more gas is produced), the effluent isremoved <strong>and</strong> a new process is started.270

Figure 1. Anaerobic digestion pathway (Erickson et al., 2004).1 Hydrolosis2 Fermentation3 Acetogenesis4 MethanogenesisComplex organic matter(carbohydrates, proteins, fats)Soluble organic molecules(sugars, amino acids, fatty acids)12Acetic acidVolatile fattyacids3Hydrogen,carbon dioxide4 Methane,4carbon dioxide271271

DigestionA sequential-batch system uses two ormore reactors. The sludge from the first reactorcontains high levels of organic acids <strong>and</strong> isinjected into the second reactor. The leachatefrom the second reactor—after the pH is adjustedwith lime or calcium carbonate—is injectedinto the first digester. Methane productionoccurs efficiently in the second reactorbecause its sludge contains little or no acid.The third process is a hybrid-batch orup-flow anaerobic sludge blanket (UASB). Itis similar to the multistage system with tworeactors. The system comprises a simple batchSummaryreactor coupled with a UASB reactor. In thisreactor, methanogenesis takes place <strong>and</strong> treatsthe liquid effluents with high levels of organicacids at high loading rates (Fig. 2).In a continuous digester, the organic materialis constantly or regularly fed <strong>and</strong> movedthrough the digester. It produces biogas withoutthe interruptions of loading the material<strong>and</strong> unloading the effluent. A continuous systemmay be better suited for large-scale operations;however, the input of carcass materialsshould be continuous <strong>and</strong> have a consistentcomposition.272

Figure 2. The schematic view <strong>and</strong> flow of materials in three types of batch reactors, includingsingle-stage, sequential-batch, <strong>and</strong> hybrid-batch (up-flow anaerobic sludge blanket digester,or UASB). (Courtesy of Erickson et al., 2004)A. Single-stage B. Sequential-batch C. Hybrid-batch UASBNew Mature OldUASB273273

Regulatory SynopsisDigestionCoordination <strong>and</strong> jurisdictional considerationsThe decision on whether to use digestionas a carcass disposal option should be madejointly by the members of the incident comm<strong>and</strong>structure established by the authoritiesin the State or local area.Local authorities should have an intercountymemor<strong>and</strong>um of underst<strong>and</strong>ing inplace so that the carcasses can easily be transportedto another county that has a digestionfacility.If the carcasses are to be transportedoutside the county for digestion, the incidentcomm<strong>and</strong> structure must consider the addedproblem of transportation safety <strong>and</strong> contaminationof property.Digestion should be undertaken only withexplicit approval by institutions <strong>and</strong> agenciesthat are competent in making determinationsabout protecting the environment.States have ranked preferred methods forcarcass disposal, <strong>and</strong> the incident comm<strong>and</strong>structure must exhaust the preferred optionsbefore undertaking digestion activities.274

Potential pollution <strong>and</strong> otherproperty-damage considerationsThe exercise of police power gives governmentalentities <strong>and</strong> agencies wide discretionin making decisions about carcass disposalto protect the public health. However,the exercise of this power does not shield thegovernmental entities against nuisance actionsif the proper precautions are not taken. In thecase of digestion, private firms engaged indigestion could face legal challenges.Critical problems associated with digestioninclude:• Spread of pathogens• Transportation• Waste treatment <strong>and</strong> disposal to preventspread of pathogens• Water contamination because of runofffrom l<strong>and</strong> application. One productfrom the digestion process is sludge, or“digestate,” that is disposed off on l<strong>and</strong>.The sludge may contain pollutants thatcould contaminate water resources fromrunoff.• Odor• Microbiological <strong>and</strong> risk of toxic gasesIf these problems occur because of governmentalaction, they could trigger nuisanceor other kinds of lawsuits. Sovereign immunitymay not be a defense to such an action.If a private firm triggers pathogen spread,the firm may be subject to both civil <strong>and</strong>criminal actions. Water contamination <strong>and</strong>odors may be a basis for a nuisance action.Digester size constraints may require theuse of inter-jurisdictional (among counties)agreements to transport large quantities ofanimals to other sites.275275

Regulatory SynopsisDigestionThe decision to use digestion must bemade jointly by the members of the appropriatetechnical group within the incidentcomm<strong>and</strong> structure because injury to peopleor property could trigger lawsuits similar tothose based on biosecurity breach.276

PlanningPlanning considerationsEvaluate in advance the advantages <strong>and</strong>disadvantages of batch versus continuous digesters.Although a batch digester is easier <strong>and</strong>less expensive to build than is a continuousdigester, a batch digester produces less gas, hasa lower loading rate, <strong>and</strong> carries more risk ofexplosion while the reactor is being emptied.A potential disadvantage of continuoussystems is that the bacterial flora may becomeacclimated to inhibitors such as ammonia <strong>and</strong>retard the production of biogas.To increase the fermentation capacity, planto use several batch digesters, <strong>and</strong> alternatethe loading <strong>and</strong> emptying processes. In such asystem, the organic material is loaded into thefermentation tank <strong>and</strong> digested for the designatedretention period. Then the effluent isremoved <strong>and</strong> the process is restarted (Fig. 3).DigestionThe volume of carcasses in lactic acid fermentationcan increase by 33 percent, mainlybecause of fermentation <strong>and</strong> carbon dioxideproduction.Plan to store the products of lactic acidfermentation <strong>and</strong> phosphoric acid preservationin sealed, vented containers. The odor ofthe final product is similar to that of fermentedmeats.Although the phosphoric acid preservation<strong>and</strong> carcass biogas production of farmcarcasses are essentially odor-free processes<strong>and</strong> are publicly acceptable, the lactic acidfermentation of farm carcasses produces volatile<strong>and</strong> odorous compounds (such as carbondioxide, ammonia, <strong>and</strong> organic compounds)<strong>and</strong> should be vented to prevent unpleasantconsequences.277

PlanningDigestionFigure 3. Operation of the anaerobicsequencing batch reactor. (Courtesy ofErickson et al., 2004)WastewaterInfluentFillReactAdd wastewaterSettleReaction periodDrawClarify° ° ° ° ° ° ° ° ° ° ° ° ° ° °IdleRemove treated wastewater° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° °° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° °Waste sludge278

Plan to use a mobile or portable unitcontaining pre-breaking, grinding, <strong>and</strong> pumpingequipment at the carcass disposal site toreduce the size of the ground materials <strong>and</strong> toeasily transfer them to the fermentation <strong>and</strong>storage tanks.A mobile power generator will be neededduring emergency situations because naturaldisasters such as floods, tornados, thunderstorms,<strong>and</strong> heat stress may interrupt power inneeded areas.For carcass biogas production, plan to usea vertical, cylindrical tank with a conical bottomto improve mixing <strong>and</strong> sludge removal.Use a properly sized conveying (piping)system to prevent clogging <strong>and</strong> special solidh<strong>and</strong>ling pumps to transfer thick sludge.Plan to use sludge from another biogasinstallation to start up a new carcass biogasproduction system. Microorganisms in municipalwastewater sludge can biodegrade awider range of organic wastes <strong>and</strong> performbetter than those from other sources, such asthe biodigesters of milk processing plants.For long-term carcass biogas production(more than 5 years), consider using a non-corrosive<strong>and</strong> acid-resistant fermentation tank,such as a stainless steel tank.Consult with construction <strong>and</strong> designengineers <strong>and</strong> obtain the required st<strong>and</strong>ards,including the technical dimensions, to useconcrete tanks for short-term carcass biogasproduction. Although concrete tanks are oftenbuilt partially below ground for better support,they should be strong enough to bear theweight <strong>and</strong> pressures (vertical <strong>and</strong> lateral) ofmixed semi-liquid materials.For efficient digestion <strong>and</strong> biogas production,plan to maintain the digester at theproper thermophilic temperatures (130 to 140°F) with properly designed heat exchange, insulation,mixing, <strong>and</strong> sludge removal systems.279279

PlanningTo prevent explosions, provide gas collection<strong>and</strong> pressure regulation equipment,including safety devices.Provide electricity (for grinding, mixing,pumping, <strong>and</strong> separation) <strong>and</strong> water for thebiodigester. Conserve water by reusing it.Propane may be needed as a fuel to start up<strong>and</strong> supply heat to the digester before enoughbiogas is produced.Plan to feed the carcasses to the activedigester before its temperature drops to below130 °F. This will prevent any delays associatedwith the digestion start-up process.Determine the volume of the digester byusing 1 pound of carcass per 4.4 cubic feet perday (3.6 kilograms per cubic meter per day),assuming that the carcasses have 0.23 pound ofvolatile solids per pound of carcass material.For example, the volume of the digesterneeded for anaerobic fermentation of 1,000Digestioncow carcasses (1,540 pounds per cow), or1.54 million pounds, is 7 million cubic feet,with a loading rate of 0.05 pounds per cubicfoot per day of volatile solids.Plan to prevent high ammonium concentrationsin the digester by increasing the ratioof carbon to nitrogen to between 20 <strong>and</strong> 40.Ammonium inhibits the biodegradation ofcarbon sources at concentrations above 0.187pound per cubic foot (3 grams per liter) of thedigesting materials.The crew will need to be protected frommicrobiological contamination <strong>and</strong> toxicgases such as hydrogen sulfide produced bycarcass biogas production.Consider also the issues related to h<strong>and</strong>ling,packing, storing, <strong>and</strong> conveying thecarcasses to the digestion facility as describedin the “General Considerations” chapter ofthis guide.280

ProceduresDigestionLactic acid fermentation or phosphoric acid preservationFigure 4. Free-st<strong>and</strong>ing polyethylenehorizontal bulk storage tank used to storelactic or phosphoric acid. (Courtesy of UnitedStates Plastic Corporation, Lima, OH)Secure the area for carcass preparation <strong>and</strong>processing from predators <strong>and</strong> vermin.Use appropriate containers, such as highdensitypolyethylene (Fig. 4) for the lactic acidfermentation <strong>and</strong> phosphoric acid preservationtanks. After grinding the carcasses, add them tothe fermentation (lactic acid fermentation) orpreservation (phosphoric acid preservation) tank.For lactic acid fermentation, mix theground carcasses with an organic compoundthat includes:• A fermentable carbohydrate such as glucose,sucrose, or lactose at a ratio of 10percent by weight• Whey, at 17 percent by weight• Molasses or condensed brewer’s solubles,at 20 percent by weight• And/or finely ground corn, at 20 to 24percent by weightGrind the fresh carcasses alone or with oneof the previously mentioned materials to particlesizes of less than 1 inch for phosphoric acidpreservation or lactic acid fermentation. Grind-281

ProceduresDigestioning the mixed materials not only promotes thehomogenization of the phosphoric acid <strong>and</strong> theground carcass material, but it also helps speedthe fermentation process <strong>and</strong> disperse <strong>and</strong> mixthe intestinal anaerobic lactic-acid-formingbacteria (Fig. 5). Do not add decomposedcarcasses to a lactic acid fermentation or phosphoricacid preservation process. A proper pHmay not be achieved for the mixed materials,resulting in further spoilage.Use starter cultures such as Lactobacillusspecies to speed up the fermentation process<strong>and</strong> provide a margin of safety under less thanideal conditions. Such conditions may includepoor mixing conditions, low fermentationtemperatures (less than 70 °F), <strong>and</strong>/or largerparticle sizes of the mixed materials.The temperature in the lactic acid fermentationtank should be maintained at 70 to 80°F to allow the sugars (fermentable carbohydrates)to be converted into lactic acid.Check the pH of the lactic acid fermentationtank 24 hours after start-up. Under properworking conditions, the pH of the mixed materialshould change from about 6 to less than5. Within 7 to 10 days of fermentation, the pHof the ground carcasses mixed with lactic acidbacteria decreases to below 4.5. At this pHlevel, the lactic acid bacteria quickly grow toconcentrations that result in the preservationof the carcass material.Pump the products of the lactic acid fermentationfrom the fermentation tank into astorage vessel.Add an amount of feed-grade phosphoricacid to make the final mixture contain 6 percentof this acid. For pickling, ground carcassesmay be dipped in either acetic acid orpropionic acid at a concentration of 10 or 3.8percent concentration, respectively.282

Figure 5. Views of a mobile grinder used to reduce the size of carcasses.(Courtesy of Haarslev, Bogensevej 85, DK-5471 Søndersø, Denmark)283283

ProceduresCarcass biogas productionSecure the area for carcass preparation <strong>and</strong>processing from predators <strong>and</strong> insects.To speed the heat transfer rate <strong>and</strong> providemore surface area for fermentation, grindthe carcasses to an average particle size ofless than 2 inches. Large pieces of bone c<strong>and</strong>amage the circulation <strong>and</strong> sludge-removalpumps.For wet digestion, mix the ground carcasseswith water <strong>and</strong> sludge from another biogasinstallation or from a municipal wastewaterfacility to achieve a concentration of totalsolid contents ranging from 10 to 15 percent.Use a fermentation tank with a floating lidto accommodate gas expansion with pressurecontrol. This type of system is more expensive<strong>and</strong> difficult to manage than is a conventionaltank with a non-floatable cover or lid.DigestionUse a mixer or circulation pump to uniformlydistribute the heat <strong>and</strong> bacteria bydisplacing or recirculating the gases collectedat the top of the fermentation tank. A recirculationpump is more expensive but moreefficient than is a mixer (Fig. 6).In addition to fresh carcasses, the productsof rendering (if not dried) <strong>and</strong> alkaline hydrolysiscan be used as input materials for biogasproduction.Incorporate manure or municipal wastewatersludge into the ground carcasses toachieve a ratio of carbon to nitrogen rangingfrom 20 to 40 <strong>and</strong> a biodegradable volatilesolids content of 60 percent of total solids.This mixture will have a culture of beneficialbacteria <strong>and</strong> the capability to biodegrade awider range of compounds <strong>and</strong> wastes. To in-284

oculate the new system, feed the reactor withsludge from another installation.Once digestion is complete, the effluentis removed <strong>and</strong> the process is restarted. Makesure to dry the sludge <strong>and</strong> store it before disposalas a fertilizer.Figure 6. The flow diagram of a wet system. (Erickson et al., 2004)OilElectricityDual fuel engineGeneratorBiogasDigesterHeatexchangerHeat exchangerGasometerDigesterCarcass inSludge out285285

SafetyDigestionTable 2. <strong>Guide</strong>lines for the use of personal protective equipment for digestion operations.Natureof workDirecth<strong>and</strong>ling ofcontaminatedmaterialNo directh<strong>and</strong>ling ofcontaminatedmaterialZoonoticagentDisposableparticulaterespirator(N95, N99,or N100);half or fullfacepieceMask/respirator a,bAs directedby the facilitysafety officerNon-zoonoticagentNonerecommendedunless for foot<strong>and</strong>-mouthdiseaseAs directedby the facilitysafety officerProtective Eye protection a Gloves a Head/footclothing a protectionImpermeableto liquids;may vary,dependingupon the heatsituationAs directedby the facilitysafety officerFull facepiecerespirator orindirectly ventedgoggles; contactlenses should notbe worn undergoggles or safetyglasses; considerprescription safetygoggles; face shieldunless wearinga full facepiecerespiratorSafety eyewearGloves: Heavyduty (15–18mil) chemicalresistant glovesthat can bedisinfected ordisposed ofAs directed bythe facility safetyofficerFeet: Forworkersh<strong>and</strong>lingcarcasses, steeltoe/steelshankwaterproofboots; forothers, steel-toework shoes orbootsHead: Hard hatAs directedby the facilitysafety officeraFor a list of vendors recommended by OSHA, visit www.safetyequipment.org.bFor information about a full respiratory protection program, visit www.osha.gov/SLTC/repiratoryprotection/index.cRegulations governing the use of personal protective equipment in hazardous waste operations can be found at 29 CFR 1910.134<strong>and</strong> 29 CFR 1910.156 <strong>and</strong> are summarized in the Safety section of the “General Considerations” chapter of this manual.286

Diseases of concernFor digestion methods, the diseases ofconcern include those caused by viruses, bacteria<strong>and</strong> prions.Viruses <strong>and</strong> non-spore-forming bacteria:As with other methods, the periodsof greatest risk will be during transport <strong>and</strong>disposal of the contaminated material. Nonspore-formingbacteria <strong>and</strong> viral diseases aregenerally destroyed by anaerobic digestion at131 °F (55 °C); however, all pathogens varyin the amount of time it takes to be deactivatedeffectively. For these reasons, digest allnon-spore-forming bacteria <strong>and</strong> viruses for 8days to ensure complete inactivation.Diseases for which digestion methodsare appropriate include African swine fever,highly pathogenic avian influenza, brucellosis(melitensis, abortus, suis <strong>and</strong> canis), classicalswine fever, contagious bovine pleuropneumonia,foot-<strong>and</strong>-mouth disease, gl<strong>and</strong>ers,Japanese encephalitis, Q fever, Rift Valleyfever, rinderpest, tularemia, <strong>and</strong> vesicularstomatitis.Spore-forming bacteria: Spore-formingbacteria are temperature susceptible. If notdestroyed, they will persist in the environmentfor long periods. If immediate incineration ofthese carcasses is not possible, the carcassesmust remain intact to prevent the spread ofspores into the external environment.It is recommended that anthrax-infectedcarcasses be incinerated or inactivated byalkaline hydrolysis. Anaerobic digestion isnot recommended for spore-forming bacteriaunless a high-heat treatment will be conductedafter the digestion process.Diseases of concern include anthrax.Prions: Prions are temperature resistant.287 287

SafetyExposure to extremely high temperatures(more than 1,830 °F, or 1,000 °C) for at least15 minutes is necessary to destroy prion-infectedcarcasses. If they are not heat inactivated,the prions will persist in ash or soil fora considerable period.Site safetyDigestionAnaerobic digestion is not an effectivemeans for destroying TSE-infected carcasses,<strong>and</strong> therefore should not be performed onthem. TSE diseases include bovine spongiformencephalopathy, chronic wasting disease,<strong>and</strong> scrapie.Heat stress: See the guidelines on heatstress in the Safety section of the “GeneralConsiderations” chapter of this guide.First aid: Make first aid available to employeesat all times.Safety observers: Use a safety observerwho has the authority to stop <strong>and</strong> correct unsafeconditions or operations.Chemical hazards: Provide safety showers<strong>and</strong> emergency eyewash stations within20 feet of each digestion tank. Caustic chemicalburns are exceptionally hazardous <strong>and</strong>can cause irreparable damage to the eyeswithin seconds if not removed using copiousamounts of water for at least 15 minutes.Workers exposed to any amount of sodiumhydroxide in their eyes should use an eyewashstation <strong>and</strong> report to the nearest emergencyroom.Ventilation: Although digestion tanks useenclosed pressure vessels, the area surroundingthe vessel should be ventilated adequately.288

BiosecurityFacilities that accept contaminated materialsmay be fixed-site facilities located onheavily trafficked public or private property,such as university campuses. Movement ofnon-zoonotic-contaminated plant or animalmaterial onto these sites should be very carefullyplanned.Although transporting carcasses contaminatedwith non-zoonotic material does notpresent a health hazard to the public, a significanteffort must go into public awareness <strong>and</strong>public relations activities well before any carcassesare moved to the site. Do not use suchfacilities to dispose of carcasses contaminatedwith zoonotic agents or transmissible spongiformencephalopathies (TSEs).Decontamination of vehicles <strong>and</strong> anycontaminated personnel must occur before theDigestionvehicles leave the disposal site. See additionalmaterial in the Safety section of the “GeneralConsiderations” chapter of this guide.Release of the digested material must becoordinated with local <strong>and</strong> state public health,environmental quality <strong>and</strong> l<strong>and</strong>-use authorities.A public relations plan should alreadybe in place before disposing of any digestedmaterial in a public sewer system or on l<strong>and</strong>,<strong>and</strong> it must be performed fully in conjunctionwith state <strong>and</strong> local authorities.To ensure the inactivation of all pathogens,have this material tested before disposalor reuse.Direct contact may be possible by workerexposure to dust or biosolids that have beenapplied to crops in the field.289

Environmental ImpactsDigestionGroundwater pollutionClose coordination with state <strong>and</strong> localhealth <strong>and</strong> public works authorities is essentialbefore the release of any digested materials.No notable groundwater pollution shouldbe present if all procedures are followedcorrectly. If necessary, groundwater may bechecked using a groundwater monitoringprogram.Digested materials should be tested fordisease-causing organisms before they arereleased onto l<strong>and</strong> or into bodies of water.Although direct release of digested sludgeinto surface waters is not recommended <strong>and</strong>may be illegal in some jurisdictions, runofffrom l<strong>and</strong>-applied digested material does havethe potential to be released or migrate to surfacewater bodies, particularly if the l<strong>and</strong> onwhich the sludge is being applied is immediatelynext to such water bodies. This situationis analogous to the movement of constituentsof l<strong>and</strong>-applied manure migrating to surfacewaters.290

Soil pollutionNo soil pollution concerns are associatedwith digestion processes unless throughuncontrolled disposal.L<strong>and</strong>fill disposal: Some tissue, such asbone <strong>and</strong> teeth, may remain after the digestionAir pollutionNo notable emissions are associated withdigestion methods of disposal. The biogasgenerated from the digestion of carcasses <strong>and</strong>manure will be composed of mainly carbondioxide (about 40 percent) <strong>and</strong> methane (about60 percent) <strong>and</strong> trace amounts of hydrogensulfide, nitrogen, oxygen, hydrogen, <strong>and</strong> othercompounds such as methyl mercaptans.process. This can be ground <strong>and</strong> disposed ofin l<strong>and</strong>fills as solid waste according to state<strong>and</strong> local solid waste regulations.All waste must be tested before movementor transfer to l<strong>and</strong>fills or other disposal sites.Concerns are limited to the on-site workers,who will need personal protective equipmentto minimize their exposure to airborneor aerosolized agents. Hydrogen sulfide maypose an immediate exposure risk to on-sitepersonnel; it does not pose a risk to the publicor the environment.291 291

CostThe cost breakdown for anaerobic digestiondestruction follows the general specificationsin the Cost section of the “GeneralConsiderations” chapter of this manual.The direct fixed cost depends on facility’scapacity (Table 3). The direct cost estimatesvary greatly, depending on the ability toreduce energy expenditures by harvestingelectricity <strong>and</strong> generating heat during theanaerobic digestion process (Table 4).For indirect cost items, see the Cost sectionof the “General Considerations” chapterof this guide.DigestionFigure 7. Components of direct <strong>and</strong>indirect costs for digestion methods.Maintenance<strong>and</strong> repairSpreading costInterest rateDepreciationEnvironmentalimpactsOthersManagementTransportation292

Table 3. Initial investment <strong>and</strong> annual direct fixed cost estimates ofanaerobic digestion with an annual capacity of 637,000 pounds, or 850cows per year.Item Investment Depreciation Interest rate(6%)Annual costDigester $350,000 $17,500 $21,000 $38,500Electrical <strong>and</strong> heating $235,000 $11,750 $14,100 $25,850systemSolids <strong>and</strong> liquids$89,000 $4,450 $5,340 $9,790separationLiquid storage $315,000 $15,750 $18,900 $34,650Others $43,800 $2,190 $2,628 $4,818Total $1,032,800 $51,640 $61,968 $113,608Source: Wright, P., <strong>and</strong> S. Inglis (2003). An Economic Comparison of Two Anaerobic DigestionSystems on Dairy Farms. ASAE Annual International Meeting, Las Vegas, NV, July 27–30, 2003.Note: The life expectancy of the investment is assumed to be 20 years.293 293

CostDigestionTable 4. Estimates per carcass of direct variable cost items of anaerobic digestion.CattleCalvesWeanedhogsPreweanedhogsOthers(sheep,lambs, goats)Estimated average direct variable cost per carcassMaintenance 1 , repairs, insurance $34.85 $12.36 $6.18 $0.28 $3.58Spreading $68.24 $24.20 $12.10 $0.55 $7.01Management $7.49 $2.66 $1.33 $0.06 $0.77Benefit from electricity savings -$49.88 -$17.69 -$8.85 -$0.40 -$5.12Benefit from heat savings on farm -$7.06 -$2.50 -$1.25 -$0.06 -$0.72Average direct variable cost per carcassExcluding benefits from energy savings $110.58 $39.22 $19.61 $0.89 $11.36Including benefits from energy savings $53.64 $19.03 $9.51 $0.43 $5.52aThe maintenance cost per herd is calculated at $29,619/850 lb.Source: Wright, P., <strong>and</strong> S. Inglis (2003). An Economic Comparison of Two Anaerobic Digestion Systems on Dairy Farms. ASAEAnnual International Meeting, Las Vegas, NV, July 27–30, 2003.294

Table 5. Estimates per ton of directvariable cost items of anaerobic digestion forcattle, calves, weaned hogs, preweaned hogs,<strong>and</strong> others (sheep, lambs <strong>and</strong> goats).Besides equipment, management <strong>and</strong>spreading costs, the disposal cost includesa transportation cost, which depends on thedistance that the carcasses are moved.ConsiderationCostMaintenance a , repairs, insurance $92.93Spreading $181.97Management $19.97Benefit from electricity savings -$133.01Benefit from heat savings on farm -$18.83Average direct variable cost per tonExcluding benefits from energysavingsIncluding benefits from energysavings$294.87$143.03aThe maintenance cost per herd is calculated by$29,619/850 lb.Source: Wright, P., <strong>and</strong> S. Inglis (2003). An EconomicComparison of Two Anaerobic Digestion Systems on DairyFarms. ASAE Annual International Meeting, Las Vegas, NV,July 27–30, 2003.295295

CostDigestionFigure 8. Formulas to estimate the direct variable cost relating to anaerobic digestion deconstruction.Direct variable cost (DVC), excluding benefits from energy savings:• By number of carcasses:DVC = 110.58Q cattle+ 39.22Q calves+ 19.61Q weaned hogs+ 0.89Q preweaned hogs+ 11.36Q othersWhere Q iis the total number of carcasses of animal category i.• By weight:DVC = 294.87(W cattle+ W calves+ W weaned hogs+ W preweaned hogs+ W others)Where W iis the total weight in tons of animal category i.(Figure continued on next page)296

Figure 8. (Continued)Direct variable cost (DVC), including energy savings <strong>and</strong> sale:• By number of carcasses:DVC = 53.64Q cattle+ 19.03Q calves+ 9.51Q weaned hogs+ 0.43Q preweaned hogs+ 5.52Q othersWhere Q iis the total number of carcasses of animal category i.• By weight:DVC = 143.03(W cattle+ W calves+ W weaned hogs+ W preweaned hogs+ W others)Where W iis the total weight in tons of animal category i.297297

Emerging MethodsSummaryDefinition <strong>and</strong> objectivesEmerging methods for disposal of contaminatedbiomaterials include new evolvingdisposal technologies, nontraditional disposalmethods, <strong>and</strong> alternative disposal methods.Evolving disposal technologies useheat or irradiation processes to inactivate thedisease-causing organisms associated withdead animals. In some cases, the carcassesare converted to inert end products. Evolvingdisposal technologies include gasification,plasma technology, thermal depolymerization,dehydration, <strong>and</strong> extrusion.Nontraditional disposal methods includeocean disposal <strong>and</strong> the feeding of carcasses toexotic animals such as alligators.Alternative disposal methods can beused to dispose of plants contaminated withpathogens that do not threaten public health.An example of these methods is crop rotation.The objectives of these emerging methodsmay include:• To quickly <strong>and</strong> safely dispose of largenumbers of animal carcasses before theydecay or deteriorate• To prevent environmental contamination<strong>and</strong> reduce public health hazards duringanimal disposal• To eliminate the extensive amount ofl<strong>and</strong> needed by some conventionalcarcass disposal methods; however,an even larger area of ocean might beneeded• To use the most cost-effective means toeliminate or reduce the populations ofplant pathogens in the fieldFor all of these methods, no specific298

esearch information is available on whetherthey can destroy transmissible spongiform encephalopathiesfrom carcasses contaminatedwith them.Evolving disposal technologies: General descriptionEvolving disposal technologies includegasification, plasma technology, carcassthermal depolymerization, dehydration, <strong>and</strong>extrusion. Because of their heat generation orirradiation processes, most evolving disposaltechnologies can inactivate microbial cells <strong>and</strong>viral particles, including airborne pathogens.Most of these technologies offer several potentialadvantages. Once full developed, they:• Can be set up as mobile units that canbe moved quickly to the disaster area• Generate no leachate from the carcasses<strong>and</strong> prevent the contamination of soil,groundwater, <strong>and</strong> surface water• Emit fewer noxious gases <strong>and</strong> odorsthan do some conventional methods,such as air-curtain burning, open-airburning, <strong>and</strong> composting• Allow for better control of operating parameterssuch as temperature, moisturecontent, pH, <strong>and</strong> particle size, whichresults in a more uniform productA disadvantage of most evolving disposaltechnologies for animal disposal is that theyhave low throughput <strong>and</strong> are not economicallyfeasible for disposing of large numbers of animalcarcasses. However, these methods can bemodified for higher throughput.For most evolving disposal technologies,the carcasses are fed as shredded or groundmaterial. This preprocessing requires stricterbiosecurity measures than for intact carcasses.299299

Emerging MethodsSummaryGasification: DescriptionIn gasification operations, animal carcassesare slowly heated <strong>and</strong> converted into a producergas that contains methane, hydrogen, carbondioxide, <strong>and</strong> carbon monoxide. Some of theproduce gas is burned to supply the heat for thegasification reactions; the rest is combusted.If practical, waste heat boilers or electricalgenerating equipment such as a Sterlingengine can be used to generate heat, steam, orelectricity produced by the operation (Fig. 1).Figure 1. Schematic of a batch-size carcass gasifier. (Courtesy ofBrookes, BGP Inc., Raleigh, NC)BurnerFluePrimary chamberFeedstockSecondary chamber800 °C300

Carcass gasification occurs at a low oxygencontent to prevent burning <strong>and</strong> at temperaturesof 1,110 to 1,900 °F (600 to 1,000 °C).Shredded carcasses can be mixed withother biowaste sources, such as manure, thatcontain a high ratio of carbon to nitrogen toimprove the gasification efficienty.The first stage of gasification requires anauxiliary fuel such as propane. The amountof fuel consumed depends on the processingtechnique <strong>and</strong> the fat <strong>and</strong> moisture content ofthe carcass.If a new batch of carcasses follows theprevious batch at a temperature higher than1,500 °F (800 °C) or lower than 740 °F (400°C), it is called a hot start or warm start, respectively(Table 1).Batch systems have limited throughputfor carcass gasification; continuous gasifyingsystems can accept higher throughput (Fig. 2).Continuous carcass gasifiers use less fuel <strong>and</strong>have a better fuel efficiency than do batchsystems. No continuous gasifiers yet exist atpractical scale as of the writing of this h<strong>and</strong>book.The carcass gasification throughput is morethan 10 tons per day in Scotl<strong>and</strong> (Fig. 3); inthe United States, the throughput for a singlebiogas plant gasifier under development isabout 25 tons per day, which can be scaled upto 200 tons a day if multiple gasifier units areconnected to a single high-capacity macerator.The amount of time required to gasifycarcasses depends on the gasification capacity,the technique, <strong>and</strong> the nature of carcass materials.Converting carcasses to gas may take 4to 12 hours, with a resulting ash <strong>and</strong> char ofabout 5 to 15 percent by volume.The disposal of ash is similar to the proceduresfollowed after carcass incineration infixed-facility incinerators.301301

Emerging MethodsSummaryTable 1. Gasification efficiency factors.Feed stock typeSet temperature(°C)DM a processed(kg)Propane, ft 3Run time(min)Propane(gal/kg DM a )Feces ws 800 31.0 144 225 0.126Feces hs 800 31.7 65 150 0.058Chicken litter cs 750 31.1 294 368 0.261Chicken litter ws 870 31.8 114 240 0.099Pig carcasses ws 800 21.1 ~600 315 0.780Pig carcasses hs 800 21.1 ~200 130 0.261Poultry carcasses hs 870 28.0 125 286 0.124a= dry matterws= warm startcs= cold starths= hot start302

Figure 2. Schematic of a continuous-carcass, feed-style gasifier.(Courtesy of Brookes, BGP, Inc., Raleigh, NC)110132311612917548141 Feeding hopper for sludge-like waste (possibly macerated carcasses)2 Continuous-feed auger zone for conveying material in the drying zone3 Drying zone for carcass materials4 Feeder zone for conveying the warm <strong>and</strong> dehydrated carcasses by thesecond auger to primary chamber for gasification5 Primary chamber for gasification6 Feeder zone for conveying gasification7 Carbon cycle or carbon chamber of carcass gasification8 Unloading zone for remaining ash9 Fuel-heating chamber10 Exhaust emission channel11 Insulating materials12 Brick walls13 Air filter14 Discharge ash auger303303

Emerging MethodsSummaryFigure 3. Views of carcass gasifying system used in Scotl<strong>and</strong> for the bovine spongiformencephalopathy crisis. (Photos courtesy of Brookes, BGP, Inc., presented in the North CarolinaDisposal Roundtable, Farm Bureau Federation of Raleigh, NC, March 30, 2006)304

Plasma technology: DescriptionPlasma technology fluidizes, or convertsinto a fluid, the inorganic portion <strong>and</strong> heatresistantmaterial of animal carcasses at veryhigh temperatures (up to 7,000 °C) after itsorganic portion is converted to vapor at 200 to600 °C (with no added oxygen 2) <strong>and</strong> convertedto gas at 600 to 1,000 °C (with limited oxygen).The resulting molten slag (Fig. 4) is collectedin a separate container, where it coolsinto glasslike material (Fig. 5).Plasma technology is the application ofartificial lightning to gasify organic materials(biogas generation) <strong>and</strong> melt inorganic materials,including animal carcasses.The gases emitted in this method can beused to produce methanol. The final rock-likeresidue is highly resistant to leaching. Also, itis a good raw material for manufacturing variousforms of brick <strong>and</strong> tiles or the concretefiller used in insulation, roadbed construction,<strong>and</strong> composition roofing. No special wastedisposal is required.Although no operating systems are available,a mobile system could process 6 to 8tons of small, intact carcasses (up to 100pounds) per day. A plasma reactor eliminatesthe need to shred the carcasses <strong>and</strong> improvesworker safety.A plasma technology unit has the potentialto convert temporarily stored animal carcasses,such as those that have been buried or composted,into inert materials of lower volumethan the original mixture of soil/organic matter<strong>and</strong> carcasses.305305

Emerging MethodsSummaryFigure 4. An overall view of shredding, feeding, organic gasifying, melting,<strong>and</strong> solidifying of inorganic materials using carcass plasma technology.(Courtesy of Dr. Lou Circeo, Georgia Tech Research Institute, Atlanta, GA)HopperLarge carcassshredderGatesPlungerGastreatmentPlasma torchMolten slagMoltenearth306

Figure 5. Schematic diagram of plasma technology for disposal of animal carcasses.(Courtesy of Kent Munden, USDA-APHIS, Clifton, TX)Plasma-fired pit burnerPlasma torch(1–2.5 MW)Pit cover(as required)<strong>Animal</strong> carcasses(20–30 tons)Soil layers–1Soil layerFire boxPipe9’Gas treatment(20–30 tons)AdditionalSoil layerair(as required)30’ 9’307307

Emerging MethodsSummaryThermal depolymerization: DescriptionThermal depolymerization technologycan treat ground carcasses under high pressure(600 pounds per square inch, or about 40bars) <strong>and</strong> high temperatures (steam heating atabout 480 °F or about 250 °C) in the presenceof carbon monoxide to create useful organicproducts such as biofuels.After 15 minutes of carcass depolymerization,the reactor pressure is released rapidlyto evaporate most of the water <strong>and</strong> separatethe liquid crude hydrocarbons from the solidminerals.Although depolymerization of carcassesis conducted at the molecular level <strong>and</strong> caneffectively destroy pathogens, it does not inactivateabnormal proteins such as prions.A thermal depolymerization plant hasbeen built in Carthage, MO, to digest 200 tonsof turkey processing waste per day.This technology is expensive <strong>and</strong> requireshighly skilled personnel to operate the system.The raw materials <strong>and</strong> residuals are keptin sealed containers before <strong>and</strong> during processing.The residuals, generally minerals, canbe l<strong>and</strong>-applied as fertilizer.308

Dehydration <strong>and</strong> extrusion: DescriptionIn the dehydration <strong>and</strong> extrusion process,superheated air moves the particles of groundcarcasses into a hot channel to evaporate<strong>and</strong> reduce their moisture. The materials areconveyed to an extruder barrel, where theyare blended, cooked, sheared, kneaded, <strong>and</strong>formed into a plastic-like material that is convertedinto dried animal feed.Ground carcasses such as swine are dehydratedin a fluidized bed dryer or a flash dryer(high temperature <strong>and</strong> short exposure) at 212°F (100 °C) <strong>and</strong> mixed with an organic carriersuch as finely ground soybean. This processreduces the moisture content of the mixedmaterials to about 30 percent <strong>and</strong> facilitatesthe extrusion process. The amount of eachspecific carrier depends on the moisture <strong>and</strong>fat contents of the dead animals.The mixed materials are conveyedthrough an extruder channel <strong>and</strong> subjected tofriction heat, shearing, <strong>and</strong> pressure. Extruderscrews force the material to pass through a seriesof hot channels where, within 30 seconds,the temperature rises from 240 to 2,800 °F(115 to 1,550 °C) <strong>and</strong> the pressure rises from294 to 600 pounds per square inch (20 to 40bar). The product exp<strong>and</strong>s <strong>and</strong> loses 12 to 15percent of its moisture content because thehigh pressure drops suddenly to atmosphericpressure as the product leaves the extruder.This new technology may emerge as analternative to the rendering of dead animals,because the final product has more nutritionalfeed value than does the carcass meal producedin rendering plants.Dehydration of dead pigs is more efficientthan that of poultry or cattle because swinehave more fat <strong>and</strong> less water.Flash dehydration of ground carcassescauses little damage to protein quality, <strong>and</strong> the309309

Emerging MethodsSummarydried animal feed has superior protein digestibility.If the product must be sterilized, themeal can be dehydrated further to about 10percent moisture <strong>and</strong> subjected to extrusionprocessing.Because of the high processing temperatures<strong>and</strong> pressure, the extrusion of ground<strong>and</strong> dehydrated carcasses readily inactivatesall bacteria, molds, viruses, <strong>and</strong> spores in thecarcasses. However, this process should notbe used for disposal of carcasses contaminatedwith transmissible spongiform encephalopathies.After dehydration <strong>and</strong> extrusion of groundcarcasses, the feed can be processed further toseparate the fat from protein.Nontraditional disposal methods: DescriptionNontraditional disposal methods includedumping carcasses into the ocean <strong>and</strong> feedingcarcasses to exotic animals.General descriptionAlthough intact carcasses can be fed toexotic animals without significant pre-treatment,the carcasses can be disposed of morequickly if they are preprocessed (for example,by grinding them) <strong>and</strong> if adequate storage isprovided.310

Ocean disposal: DescriptionIn the ocean disposal method, carcasses areplaced deep in the ocean to prevent flotation <strong>and</strong>allowed to gradually disintegrate. Ocean is definedas the waters lying seaward of the baselinefrom which the territorial sea is measured.To transport carcasses for the purpose ofocean dumping, you must obtain a permit fromthe Environmental Protection Agency, accordingto the Marine Protection, Research <strong>and</strong>Sanctuaries Act (MPRSA, 33 USC § 1401 etseq.).To obtain an ocean-dumping permit:• The dumping must not unreasonably degradeor endanger human health, welfare,or amenities or the marine environment,ecological systems or economic potentialities.• The material must be placed in an approvedocean-disposal site.• The materials must undergo a series oftests <strong>and</strong> evaluations to determine whetherthey meet the EPA’s ocean-dumpingcriteria (40 CFR Parts 227 & 228). Thesecriteria include consideration of the effectsof disease-causing organisms, hazards tonavigation, <strong>and</strong> dangers to shorelines <strong>and</strong>beaches as a result of the dumping.Virtually all materials dumped in the oceantoday are dredged materials from navigationchannels <strong>and</strong> berthing areas.An emergency permit is required <strong>and</strong> maybe issued if the emergency poses an unacceptablerisk relating to human health <strong>and</strong> there is noother feasible solution.No permits, even emergency permits, maybe issued for dumping or biological warfareagents.311311

Emerging MethodsSummaryOther considerationsWhen the EPA issues an emergencyocean-dumping permit, the agency determinesthe location <strong>and</strong> method of dumping as a conditionof the permit.Avoid dumping animal carcasses near theshore because they may attract scavengers <strong>and</strong>cause health problems for the people living orrecreating near the ocean.Dumping large quantities of animal carcassesin one location (overdosing) may resultin floating debris <strong>and</strong> “dead zones,” whichwould not be allowed under an ocean dumpingpermit.Roll-off dumpsters may be used to transportthe carcasses from the farms if the carcassesare packed with inert, nontoxic materialsto prevent them from floating.The number of personnel needed forocean disposal has not been determined, but itmay be a major issue in an emergency animaldisposal event.Research has not been conducted on whatwould happen to the disease microorganismsif animal carcasses were dumped in the ocean.It is not clear whether the pathogens could bere-introduced to farm animals through fishmeal in the feed or spread to marine animals<strong>and</strong> seabirds.312

Refeeding: DescriptionRefeeding methods use whole or shreddedfarm carcasses as feed for exotic animals <strong>and</strong>at fur <strong>and</strong> trout farms.According to the National Contract PoultryGrowers Association, alligator farmingoperations have become a viable option fordisposing of hundreds of thous<strong>and</strong>s of chickensthat die before they reach the processingplant.If a large number of carcasses were causedby a natural disaster, they would need to bepreprocessed to inhibit decomposition <strong>and</strong>then stored in sealed containers or frozen untilthey were consumed.In some states, such as Louisiana, rawpoultry carcasses cannot be fed to hogs or alligatorsunless the carcasses are first cooked orrendered.Rendered-animal carcasses are usuallyfed at fur farms; however, in some states suchas Minnesota, non-rendered animal carcassescan be fed to fur animals if these requirementsare met:• A permit to feed these animal carcassesis obtained.• The carcasses, facilities, <strong>and</strong> equipmentmeet the specifications of the MinnesotaBoard of <strong>Animal</strong> Health (MBAH, 2003)for fur-farm consumption, <strong>and</strong> the farmis in a sanitary condition.• <strong>Animal</strong> carcasses may be fed to furbearinganimals if their products do notreenter the food chain.• The fur-farm owner accepts the riskof diseases being transmitted from thecarcasses to the fur animals.313313

Emerging MehodsSummaryAlternative disposal methods: General descriptionAlternative disposal methods focus mainlyon crop rotation to naturally dispose of contaminatedplant materials. If the plant diseaseis not considered an immediate threat <strong>and</strong>if the pathogen does not pose an epidemicconcern, the disease spread can be limited byappropriate quarantines <strong>and</strong> disease monitoring.Crop rotation is a natural but powerfultool for eliminating non-threatening pathogensin the field. This method is often used toreduce plant pathogen populations in agriculture.At the end of the growing season, thecontaminated crops will degrade naturally inthe field.Usually in the next growing season, cropsthat do not serve as hosts for the pathogensare planted in the contaminated field. If thecrops are rotated properly, many pathogenseither die out or their concentrations arereduced sharply. For this reason, it is recommendedthat you consult with county Extensionspecialists to select an appropriate crop.Soil-borne pathogens that typically infectplants of one or a few species can be reducedsignificantly by planting, for 3 to 4 years,crops that belong to species or families notattacked by the particular pathogen.Crop rotation can effectively eliminatepathogens that are typically considered soilinvaders; these survive only in living plants orin the plant residue that persists in the soil. Inthe U.S. Midwest, maize <strong>and</strong> soybean cropsare rotated to manage plant pathogens.314