Urban Digestive Systems. Towards the Sentient City. - MIT ...

for the 21st Century,” a ubiquitous logic deeplyembedded in everyday environments andactions (Weiser 1991). His vision liberatesinformation from the virtual space behind thescreen. Instead, technology is seamlessly embeddedin every object, effortlessly integratedinto daily routines. Arranging smart objectson a table triggers meaningful computationalinteractions, just as command sequences doon a traditional computer. Using sensor data,phones automatically recognize social context,such as a meeting or film screening, and adjusttheir behavior accordingly.This idea extends to scenarios where everyobject can sense relevant information about itsenvironment, infer the situation, and spontaneouslycommunicate with nearby devices orbroadcast its state to the world. Julian Bleeckerdubbed these blogging objects, or ‘blogjects’(Bleecker 2005). Alternatively, as sensingdevices miniaturize and distribute pervasively,they become smart dust, an invisible, intelligentinfrastructure for real-time environmentalsensing. Through such transformative technologies,the Sentient City can meet our growingdemand for rich, accurate, timely information.Smart dust, in particular, was a usefulstarting point for investigating the movementof garbage. We scattered our location sensorsinto the removal chain like dust particles in thewind, with no hope of retrieving them afterwards.The sensors journeyed within heaps oftrash, detected their own locations, reportedback to our servers, and allowed us to observethe unseen infrastructure they inhabited.Eventually, their batteries depleted and theircircuits were damaged from wear and tear, theystopped speaking and became indistinguishablefrom the surrounding trash.***In 2008, journalists from Greenpeace investigatedrumors of electronic waste exporting,a legal practice in the United States, butoutlawed in most countries of the world as aresult of the International Treaty of the BaselConvention. The journalists embedded GPSsensors into television sets that were brokenbeyond repair, and brought them to a localrecycling facility in the UK. Despite legislationbanning the movement of e-waste betweennations, the defunct televisions were trackedall the way to Nigeria, where they were likelyillegally dumped.Waste removal is a complex process,subject to myriad regulations and multipleexchanges that are difficult to track. Potentialfor fraud has always existed in this tangledweb, driving a long history of organized crimecontrol over the industry in various parts ofthe world. Most often this disproportionatelyaffects poorer areas over wealthier ones, raisingquestions of environmental justice whenthe consequences threaten public health.Globalization has made these transboundaryissues, as people attempt to cheaply exporthazardous waste to countries with lax regulations,instead of complying with local standards.Paradoxically, the very regulations thatshould prevent misuse have generated a greymarket for waste, where profit can be madeby bypassing legal procedures.The sheer volume of garbage that wegenerate also threatens sustainability. Goodsconsumption and garbage production are constantlyrising, yet safe and affordable landfillspace is becoming harder to find. In addition,most small regional landfills at the urbanfringe have been shut down, as cities have expandedand pushed out these practices. As aresult, waste travels much further than before,using more energy and producing more emissions.Furthermore, closed landfill sites oftencarry toxic legacies that require remediationand constrain later land use; thus hazardouswaste disposal becomes especially costly andvulnerable to fraudulent practices.***To ensure responsible waste removal, theproximity principle, as outlined in the BaselConvention, demands that waste is disposedof as close as possible to its source (Kummer,1999). However, waste removal chains areoften inadequately monitored to ensureenforcement. Such chains can involve manydifferent companies, but very little informationis passed between them; a standardizedinformation model for tracking waste doesnot exist. As a result, current procedures formonitoring the process rely on paper protocolsand voluntary evaluations of facilities, asystem built almost entirely on trust.As the “following the e-waste trail” projectby Greenpeace shows, technology can overcomemany of these obstacles (GreenpeaceInternational 2008). Active GPS-based locationsensors can effectively monitor individualwaste items anywhere in the world,highlighting potential abuse. Because sensorsare irretrievable once thrown away, GSM(Global Standard for Mobile Communications)and other mobile phone networks are importantinfrastructures for real-time communication.Online databases collect and storethis data remotely; advanced analytical andmapping software allow us to make sense ofmassive amounts of location data and pickout patterns from the noise.There are also low-tech methods of trackingthe motion of refuse, like relying on manyvolunteers to act as temporary sensors. A famousnaval spill of 29,000 rubber toys in 1992enabled a long-term study of ocean currentsin the Pacific. Oceanographers Ebbesmeyerand Ingraham recruited local residents,visitors, and beach workers to recover toysbeing washed ashore in Alaska. Based on thelocations of around 400 found toys, scientistsrefined their models of oceanic currents andcorrectly predicted the trajectories of theremaining toys (Ebbesmeyer et al. 2007). Thisdemonstrates what can be achieved by engaginga community even without expensivetracking technology.Beyond the tracking process itself, there areimportant precedents for communicating ourobservations to the public. One relevant priorwork is Eric Paulos’ Jetsam project (Paulos andJenkins 2005), which sought to improve publicawareness of waste issues. They deployed atrash bin in public space that was equippedwith various sensors and network connectivity.This ‘augmented trash bin’ gave feedback toits users by displaying statistical informationabout collected waste via projected visualizations.Such real-time feedback can deliverinformation about waste disposal in an intelligible,resonant way, and could potentially drivegreater awareness and behavioral change.These examples are at the core of whatwe are after. Yet, Trash Track goes beyondall of the above approaches, using pervasivetechnologies and volunteer mobilization toexpose challenges of waste management andsustainability to the world. It builds on previouswork by the SENSEable City Lab thatexplores how the increasing deployment ofsensors and mobile technologies radicallytransforms our understanding and descriptionof cities. The project is an initial investigationinto understanding the removal chain in urbanareas, and represents a model for change thatis taking hold in cities: a bottom-up approachto managing resources and promoting environmentalawareness. Trash Track hints at animportant, but little discussed aspect of thevision described as the Internet of Things. Asargued by the novelist Bruce Sterling, we candirect every object to the optimal reuse scenarioand ultimately achieve a condition withzero waste, if we know where all things are inthe world (Sterling 2005).Technology DesignThe whole project has made me much moreoptimistic about our ability to find solutions tobig, complex problems. Seeing how the peopleinvolved in the project are using their creativityand scientific expertise to tackle something asmundane yet complicated as trash disposal isvery encouraging.— Trash Track volunteer survey***The Trash Track project was conceived in thesummer of 2008 as a proposal for the Towardthe Sentient City exhibition, organized by theArchitectural League of New York. Rex Britter, avisiting scientist with the SENSEable City Lab,suggested the idea of tracking garbage in thecity in order to better understand the collectionof waste — which Bill Mitchell dubbed the ‘removalchain’ as the counterpart to the supplychain — and eventually improve its logistics.Tracking trash intrigued us both as a windowinto its environmental impact on the city and asan extension to the Lab’s past work in diffusepervasive digital sensing to explore the physicalcontext of the city.The Trash Track concept also raised questionsand concerns in its developmental phase.Was the inevitable deposit of potentially toxictracking electronics into landfills contrary to theenvironmental goal of the project? Any demonstrationof this technology would inevitablyproduce a small amount of electronic waste,but the knowledge and information obtained bytracking waste products could provide enormousbenefits outweighing the risks. Thinkingahead to the future, it will be possible to carryout projects like Trash Track in more environmentallyfriendly ways. Rapid miniaturization,organically based batteries, and self-poweringmethods will all contribute to the greening ofelectronic sensing devices.94-95 MIT Senseable City Lab Trash Track

Evaluating different materials for protecting the sensors from the physical impacts inside the waste stream.***While our initial concept of tracking trash wasrelatively simple, a number of constraintscomplicated development and implementation.Due to the wide variety of waste items, materials,and treatment processes, we needed alarge number of tags to track a representativesample; distributing ten or twenty tags wouldyield only anecdotal results. It was also impracticalto try to recover and reuse tags oncethey entered the waste stream. For both ofthese reasons, it was crucial that the tags wereobtainable at very low cost.The range and variety of trash paths madethem impossible to predict a priori, so it wascritical that the tags were able to self-locateand transmit their location information fromanywhere in the country. Finally, due to the potentiallylong travel time of trash, our sensorsrequired long-lasting battery performance thatwas not easily met by off-the-shelf commercialsolutions. Most available devices have to berecharged every few days; when potentiallyfollowing garbage for months, this was notfeasible.Given the costs of active sensors, passiveRFID (radio-frequency identification) tagsseemed like an attractive alternative. RFID wasalready commonly used to track items in retailsupply chains; the low price of these tags madethem cost-effective to deploy in large numbers.However, as a near-field localization technology,RFID would have required an additionalnetwork of tag reading devices, deployed at everypotential stop and destination in the wastestream. Besides the prohibitive cost of buildingthis network from scratch, an RFID solutionwould also be unable to track the most interestingcases of trash, those that went astray fromexpected paths.Therefore, active-reporting infrastructurewas critical to tracking object movement in anunconstrained system like the waste removalchain. We chose a tracking technology basedon the GSM cell phone network, since it notonly provided a solution for location sensing,but also offered a communications channel forreporting the sensed locations back to us. Byidentifying cell towers in the proximity to thedevice and triangulating their known coordinates,GSM could provide coarse-grainedlocation sensing. In addition, the GSM networkallowed sensors to actively communicate backthrough those cell towers.***Two generations of Trash Tags were developedat MIT by utilizing an off-the-shelf GSMdata modem chipset, microcontroller, motionsensor, and a custom printed circuit boardDifferent waste items waiting to be tagged, contributed by Eatonville High School students.with an integrated trace antenna. After gainingdeployment experience with the first generationtags, a new design was developed prior tothe second production run. This developmentprocess focused on simplifying tag designin order to (1) reduce power requirements toreduce battery size, (2) shrink form size usinga low-cost, small antenna design, (3) consumefewer electronics and improve environmentalperformance, and (4) minimize packagingwithout sacrificing the robustness needed tosurvive impacts in the removal chain.To minimize power consumption, the tagswere equipped with an algorithm that wouldawaken the tag upon detection of motion by themotion sensor. Tags would scan all channelsand bands for cell towers; locate the strongesttwelve cell sites nearby and store their identificationinformation. Subsequently, the tagscompressed tower reports into Short MessageService (SMS) messages and periodically sentthem to a server; low frequency of communicationwas critical to maximizing battery life. Interms of environmental performance, the secondgeneration of tags was lead-free and usedcomponents containing very little or negligiblehazardous substances. As a result, the GSMtags complied with environmental standardssuch as the European Union’s Restriction ofHazardous Substances Directive, designed toreduce the disposal of hazardous substances inelectronic equipment.The final deployment used tracking devicesdeveloped separately by Qualcomm. Thesetook advantage of GPRS and GPS technologyto deliver more accurate location reports. TheQualcomm tags were similar in size to previousgenerations, and had a sleep mode for conservingenergy, a crucial feature for our experiment.Rather than activating on motion, the sensorswere configured to report their location everythree to six hours; we chose several differentreporting cycles to balance between the needfor longer battery life and for more detailedtraces in space and time.Evaluating tag performance in the fieldrevealed three important limitations: batterylife, failure rates and accuracy of the locationreports:— It was difficult to clearly define expectedbattery lifetime because of the varied nature ofthe conditions experienced by individual tags.Since the sleep mode is very low power relativeto when the cellular module is active, thelifetime was strongly affected by the amountof time that the tag was actually in motion, andby the algorithm for turning on the system inresponse to vibration. Based on our data, weestimated that our tags had sufficient energy96–97 MIT Senseable City Lab Trash Track

to operate for 20-30 hours when constantly inmotion, and from 3-6 months in sleep mode.— We noticed that about 20% of the tags eitherreported very short traces or failed to senda report at all. Tags could have failed for anynumber of reasons: destruction during thewaste removal process, arriving somewherethe transmission signal was blocked, hardwaremalfunctions of the tracking device, or humanerrors resulting from volunteers not disposingof the tagged item. We found that failure ratesdepended heavily on the packaging strategyand type of trash; battery failure turned out tobe less of a problem than physical destruction.— The location reports we received had limitedresolution in time, due to the power-conservingmeasures explained earlier. However, theresolution was sufficiently high for inferencesabout the route and the mode of transportation.The accuracy for GSM based localization canbe estimated at about 250 m. GPS localizationsignificantly improved this accuracy. However,since the GPS signal required a clear view ofthe sky, this feature was not always available.DeploymentsThe blend of technology, information systems,and my own lack of concrete knowledge aboutwhere trash goes were the primary catalysts.A strong feeling that I wanted to influenceothers in the Seattle area to get involved at thelocal level was a secondary — but still important— motivation.— Trash Track volunteer survey***Over several phases of the Trash Track project,we distributed a total of 3,000 sensors inthe cities of Seattle, New York, and London.The initial field test of trash tags took placein June 2009 in Seattle, Washington. Our primarygoal was to test the tags’ performanceonce they had entered the waste removalstream. We also wanted to sample data from awide distribution of disposal locations acrossthe city. Driving to these target locations, wefound many objects simply lying around onstreets and empty lots. Examples includedbeverage containers and newspapers, toysand batteries, cell phones and computers, applianceslarge and small, furniture and clothing,and hazardous materials and car parts.We tagged each of these found items, tryingout different techniques for attaching themsecurely. Tagged objects were then droppedinto public garbage bins, brought to recyclingcenters, returned to retailers via take-back programs,dropped on the curbside of residentialhomes, or, in a single case, left provocativelyin public space. We quickly realized that additionalmeasures were necessary in order toprotect the tags from physical damage, ensureproper signal transmission, and conceal themto prevent manual removal. In order to achievethese partially conflicting goals, we experimentedwith different methods for protectingthe sensitive devices.This turned out to be an assembly problemof a very peculiar kind, since we neededto be able to secure a tag to a wide range ofmaterials and geometries. Encasings of latexmold rubber and carbon fiber provided effectiveprotection, but were too complicatedand time-consuming to produce on the site ofdeployment. We settled on a process whichcovered the sealed tag with a 1-2 inch thickshock-absorbing layer of sturdy foam basedon epoxy resin, a quick-setting material alsoused for insulating and patching boat hulls.For some electronic waste, tags could alsobe embedded into the interior circuitry ofthe object. Special care was given to deviceswith metal cases, to prevent Faraday cagesfrom blocking of blocking wireless signals.***The following August, we distributed an additional600 tags in the city of Seattle, usinga threefold approach. A portion of the tagswas distributed during a public event at theSeattle Central Library, at which volunteerseach brought to us an object to be tagged,which they would then disposed of. For asecond portion of tags, our team arranged tovisit volunteers at their homes, attaching tagsto their prepared garbage objects and havingthe volunteers dispose of them as they normallywould. Finally, the remaining tags weredeployed directly by our team across the metropolitanarea, covering the full range of materialsand garbage types (such as plastic, metal,e-waste, etc.), different geographic areas, anda variety of garbage disposal methods.We were struck by how strongly the publicresponded to the project. Within two days ofsending out a newsletter announcement inSeattle calling for volunteers, we had receivedmore than 200 responses - far beyond ourexpectations. It suggested just how engagedthe general public could become in researchingwhere trash goes. This also contributed to ourdecision to set up subsequent deployments ofmany tags with expanded involvement by localvolunteers. Following our August experiment inSeattle, two smaller experiments were carriedout in the cities of New York City and London.In September of 2009, preliminary resultsfrom these efforts were shown to the publicin exhibitions at the Seattle Public Library andthe Architectural League of New York. In bothexhibitions, a real-time visualization based oncollected sensor data provided a compellingportrait of the journey of the tracked garbage,item by item. Each representation includeda photo with the description of the disposedobject, where and when it was thrown away,and an animated view of the object’s trajectorythough the waste system. These data visualizationswere combined with a video composedby German artist Armin Linke for this exhibition,which showed scenes from the insideof waste management facilities, juxtaposingclean abstract data with the brute physicalityof waste.***In October 2009, building on experiencesfrom this initial phase and the exhibitions, weprepared for our largest deployment to date.In order to launch 2,200 location sensors in themetropolitan area of Seattle, we extended ourcollaboration with local citizens. We recruitedvolunteers through an open call in local media,in which we asked them to provide garbageitems from their own households according toa wish list of items. From the pool of volunteerswho registered through our web site, weselected around 100 homes to visit, in orderto achieve an even geographic distribution ofdisposal points across the whole region.During the following three weeks, fourmobile deployment teams visited the homesof selected volunteers, elementary and highschools, and private institutions. The SeattleCentral Library served as a base of operationsfor preparing the tracking devices and thematerials necessary for the deployment, aswell as for training lead volunteers who joinedus during visits to homes. On site, the team attachedtags to trash using layers of protectiveepoxy foam, and documented each item, itsmaterial properties, and the time and locationof its disposal.In order to achieve a diverse and representativeselection of household wastes, weprepared a ‘wish list’ and some guidelines forwhat we were looking for. Two main factorsshaped the selection of trash for tagging:— Primarily, the list was based on the taxonomyused by the Environmental ProtectionAgency to divide municipal solid waste intocategories based on contained materials(Office of Solid Waste 2008b). These materialcategories include organics, paper and paperboard,glass, plastics, metals, and rubber,leather and textiles.—The second important influence in selectingproducts was the nature of the waste collectionsystem in Seattle. In this system, differentmechanisms capture different types of waste;for example, single-stream curbside recyclingcollects aluminum cans, while food and yardwaste collection handles organic scraps, andfluorescent light bulbs are collected at householdhazardous waste centers (Seattle PublicUtilities n.d.).Extra consideration was given to emergingwaste categories such as discarded cell phones,computers, fluorescent bulbs, and other householdhazardous waste, which are increasinglyprevalent in the waste stream (Office of SolidWaste 2008a). These emerging waste sourceshave an array of disposal mechanisms, many ofwhich are provided by private sources, such asmanufacturer take-backs, store drop-offs, andmail-in programs. The collection rates throughthese mechanisms, as well as their environmentalimpacts and trade-offs, are not asestablished as those of municipal solid waste.***While we varied and refined our proceduresthroughout the project, each of these deploymentsactively involved local citizens. Besidescreating public awareness about the project,its goals, and the questions it raises, this alsoensured that we could distribute our tags in away that closely matched how people in thatcity actually disposed of their trash. Recruitedvolunteers came from local neighborhoods,schools, public libraries, institutions, andcompanies, collectively providing an incrediblearray of garbage items. Volunteers also98-99 MIT Senseable City Lab Trash Track

joined us in attaching sensors to waste itemsand documenting the process. Some droveus in their private cars to deployment locationsacross the city. Finally, volunteers wereinstrumental in spreading the word and helpingto recruit others for the experiment. Mostvolunteers who signed up for the experimenthad a strong interest in environmental issuesand technology. When asked for their reasonsfor participating, they expressed curiosity anda lack of information about the waste managementprocess.ResultsI hadn’t thought about the trash having multiplestops between me and a landfill. I also realized Ihave no idea where my local landfill is.—Trash Track volunteer survey***The Trash Track deployments in Seattle producedmultitudes of data; each electronic tagregularly reported its location up to the pointof its destruction or permanent loss of signal.Thus, the data could be visualized as tracesin space and time, following each trash item’spath from its disposal point to its last known location.Coupled with descriptions and picturesof the trash, we were able to show how differenttypes of waste traveled across the country.However, these traces alone could not tellus about why trash traveled the way it did, norhelp us understand what were the functions ofeach resting point or final destination. We hadto supplement our data with thorough analysisusing maps, satellite images, published information,and direct contact with waste processingfacilities. Performing this manual processfor each tracked item helped us determinewhere it had gone, its mode of transportation,and whether it ended up somewhere it shouldnot have.***In this last section we will discuss two typicaltraces of waste products that were tracked duringthe experiment: a printer cartridge and alithium rechargeable battery. Each item’s traceillustrates the complexities and uncertaintiesinherent in predicting the movement of trash.The trace of the printer cartridge (Figure 1)reveals one way that waste removal chains operateon a national scale. The direct path fromWashington to Tennessee, spanning only sixhours with no reports along the way, impliedthis item was shipped by air freight.We saw from closer inspection that the volunteerdisposed of the printer cartridge froma residential neighborhood in the north part ofSeattle on Saturday, October 24th, as shown inFigure 2. However, exactly how they disposedof it was unclear; after leaving the house, thetag reported from a street three blocks away,but within the same neighborhood, implyingthat the cartridge was in transit by car or truck.Because the tag never arrived at a waste transferstation, we assumed that the volunteerpersonally dropped off the item at a specialdrop-off point, possibly a retail store collectingrecyclable print cartridges.The next stop of the printer cartridge wasa large truck station as shown in Figure 3.Because we could not identify any specializedwaste removal facilities nearby, we concludedthis was a logistics hub and transfer pointbetween freight trucks.The cartridge then traveled to TacomaInternational Airport, where it arrived at 3:40am on the morning of October 25th (Figure 4).The GPS coordinates match with the location ofa FedEx air freight terminal within the airport.From there, the tagged printer cartridgeflew to Memphis, Tennessee. The reported GPScoordinates indicate that the cartridge arrivedat the FedEx air freight terminal at MemphisInternational Airport by 9:40am on October25th (Figure 5), no more than six hours afterhaving arrived in Seattle-Tacoma. Incidentally,Memphis Airport is the FedEx Express ‘Super-Hub,’ processing a large portion of the packagesshipped by the company.The tagged printer cartridge continued itsway by air to Nashville International Airport inTennessee, arriving the same evening. It sat fortwo days in a US Postal Service facility nearby.At last, the printer cartridge completed itsjourney at a facility in La Vergne, Tennessee(Figure 6). The EPA Facility Registry Systemidentifies this location as an e-waste recyclingcenter called SimsRecycling, which recycles,recovers, and remanufactures electronicwaste and office products. It is surrounded byindustrial buildings but also borders severalsuburban residential communities.The ultimate fate of the printer cartridgeremains unknown. Since this was the last locationreport received from this object, it is verylikely that the location sensor was destroyed orseparated upon entering the facility. The printer1. Trace of printer cartridge deployed from a residential household in Seattle, WAto an E-waste recycling facility (SimsRecycling) in La Vergne, TN.2. Location of disposal for the printercartridge.5. Cartridge arriving at MemphisInternational Airport.3. Cartridge transported to a freighttruck facility.cartridge travelled 3,210 miles from its disposallocation to reach this point, by a combination ofroad, rail, and air freight.***By contrast, the trajectory of a tagged lithiumrechargeable battery showed much more uniformmotion across the US, as it travelled easttowards the Twin Cities (Figure7).Closely examining the origin point of thebattery shows it starting from a Seattle post officeon the afternoon of October 29, as shown6. Cartridge arriving at SimsRecycling,an e-waste recycling facility in LaVergne, TN.4. Cartridge arriving at FedEx facility inSeattle-Tacoma International Airport.in Figure 8. We assumed that the user choseto dispose of the battery through a mail-backprogram for recycling hazardous batteries.The lithium battery appeared to travelsouth by truck to Federal Way, Washington,where it arrived and stayed for the evening inanother US Postal Service facility, as shownin Figure 9. On the morning of October 30, itleft this facility to travel eastward, reportingseveral times from I-90.The battery steadily rolled east, throughIdaho, Montana, Wyoming, South Dakota, and100-101 MIT Senseable City Lab Trash Track

7. Small lithium battery trucked from Seattle, WA to a mecury recovery facility inRoseville, Minneapolis.9. Lithium battery leaving transportationfacility toward highway 90.10. Lithium battery transported onhighway 90, highway 29, highway 80and then on highway 35.Iowa, always reporting from interstate highways.There were some missing reports, whichcould have resulted from the tag temporarilylosing signal, either from being buried deepwithin the truck or entering an area without cellphone reception. In northwest Des Moines, thebattery arrived at yet another US Postal Servicebuilding. It stayed for several hours beforeheading north to Minneapolis on the evening ofNovember 1, as shown in Figure 10. Travellingat full speed along I-35, it arrived at an Eaganpost office on November 2.Finally, on November 3, the lithium batteryarrived at a hazardous waste recovery facilitycalled Mercury Waste Solutions in Roseville,Minnesota. (Figure 11) Mercury Waste Solutionspartners with Waste Management to runits LampTracker program, confirming that thevolunteer used a special LampTracker containerto dispose of the battery. The sensor sent itsfinal reports from the facility; we concluded thatthe battery and tag were likely separated here,and that this was the likely end of the battery’s3000-mile journey.These accounts illustrate the rich tracesthat can be gleaned from tracking two8. Lithium battery starting at a U.S.post office.11. Lithium battery end-of-life destination:Mercury Waste Systems.household hazardous waste items, and howtheir meaning is subject to interpretation.Geographic coordinates alone lack context;their meaning has to be inferred by makingeducated guesses, comparing the reported locationswith those of known facilities, and bydeducing transportation modes from movementpatterns in time and space.When combined with the physical characteristicsof the object being tracked, thesetraces can be used to estimate the ecologicalimpacts of the transportation process, suchas the amount of carbon dioxide emitted orenergy used in transportation and disposal.Yet, these accounts also show how difficult itis to draw conclusions from anecdotal traces,since many events in the removal process,such as how efficiently trucks and train carswere packed with transported waste, remainunknowable.Reflections[Trash Track] made me more aware of detailson how to dispose of certain items. Before, Ihad been too lazy to look up where to take anold laptop or light bulbs. I didn’t want to throwCardboard BoxDisposed atCentral Business DistrictSeattle, WA 98164DeploymentMon Oct 26 8:00 pmCentral Business DistrictSeattle, WA 98164En RouteTue Oct 27 0:53 amCardboard BoxLast seen at:Tue Oct 27 8:53 amAllied Waste RecyclingSeattle, WA 98134Pioneer SquareMon Oct 26 20:53 pmInternational DistrictTraveled3.3 MilesCategoryCardboardYesler TerraceAtlanticThe recorded trajectory of a piece of cardboard on its way to the material recovery facility in South Seattle. Image by E RoonKang and Eugene Lee.102–103 MIT Senseable City Lab Trash Track

Plastic ConeDisposed atMt BakerSeattle, WA 98144Traveled6.6 MilesCategoryPlastic OtherRiverviewSouth DelridgeWhite CenterGeorgetownEn RoutePlastic ConeLast seen at:Thu Oct 22 16:54 pmWaste Management TransferSeattle, WA 98134Mid-Beacon HillHolly ParkDeploymentThu Oct 22 4:00 amMt BakerSeattle, WA 98144Mt BakerRanier ValleyColumbia CityThe recorded trajectory of a plastic item on its way to a transfer station. Image (above and pages 106-07) by E Roon Kangand Eugene Lee.them away, so they just sat around. TrashTrack made me motivated to learn the properdisposal process for such items.— Trash Track volunteer survey***One of the most surprising things we discoveredwas how strongly the project resonatedwith volunteers, peer researchers and thegeneral public. Despite the bureaucratic auraof public services such as waste removal,trash turned out to be a very emotional topic.The people we met in the course of the projectdeeply cared about the fate of garbageand recyclables, and wanted to find out howthe city deals with them.Trash Track was originally developed foran art exhibition, and the final project sharedmany similarities with a participatory art piece.Similar to other projects by the lab that weredeveloped around a public exhibition, TrashTrack illustrates Senseable City Lab’s design,action, and intervention-oriented vision forresearch. Exhibitions, internally called ‘urbandemos,’ play an important role in the work ofthe lab, not only for discourse with the generalpublic, but also as a nucleus around which wecan set up further research. The urban demo isa broad vision of research, boiled down to anactual intervention in urban space, that communicatesa vision, demonstrates a possibletechnical implementation, and provides an approachfor producing data that can be followedup by later scientific exploration.In that sense, it is more than a traditionalscientific experiment under controlled conditions;its purpose is not only to collect data,but also to facilitate discourse. Trash Trackis an urban demo in the sense that it shows aglimpse of what the future city could look like.Even before going into the details of a specifictrace, visitors and volunteers were confrontedwith the complexity of the waste removalsystem, knowledge that might change theirattitudes and behavior as consumers.In that context, one interesting question iswhat role the museum or library could play insuch a discourse. According to Jodee Fenton,Fine and Performing Arts Coordinator at theSeattle Public Library, they see their role asengaging the community around relevant topicsby providing the best information available,without endorsing a specific view orgoal. While the project created a challenge fortheir infrastructure and institutional culture(imagine volunteers bringing heaps of trashand researchers pouring epoxy foam in thelibrary’s pristine, Rem Koolhaas-designedlobby), it still aligned well with the publicdiscourse they sought to promote.Our experiences with the exhibition validatedsome assumptions we mentioned earlier— in particular, the assumption that access toraw, personalized datasets can have a highervalue for the citizens than traditional forms ofdata representation. Volunteers developed astrong sense of ownership or emotional attachmentto the data generated by their donateditem — a fact that we acknowledged duringthe third deployment by creating a website forvolunteers, where they could track their owntagged items. They were genuinely interestedin the information they helped to generate, andless interested in the public feature of theirnames or photos of their donated objects. Butthe meaning of the data can be perceived ondifferent levels. While the explicit informationacquired through the experiment, the destinationsand trajectories of waste, facilitate insightinto the system, the data is also meaningfulon a more basic level. The complexity andthe patterns of the whole system suggestedby the data, or the mere movement of waste,are meaningful pieces of information for thevolunteers.***The Handbook of Solid Waste Managementidentifies a number of issues the field is strugglingwith, many of which stemming from alack of information. This starts with the needfor common definitions of how to categorizewaste. The biggest issue, however, is the lack ofquality data about all aspects of waste removal.As a result, it is difficult to answer questions ofhow much waste is generated, since not all ofthat waste is properly reported. Experts alsostress the current lack of consistent, predictableenforcement of regulations, which alsorelies on sound data and monitoring, particularlyon transfers between states and countries(Kreith and Tchobanoglous 2002).Trash Track substantially contributes to theavailability of quality information about thewaste removal system, providing the basis foran integrated treatment of waste, from generationto collection, processing, and recyclingor disposal. The project pursued three importantgoals: to develop appropriate trackingtechnology given the real-world conditionsof waste removal; to generate a bottom-up104–105 MIT Senseable City Lab Trash Track

Old SneakerOlympic National ParkOlympiaDeploymentMon Oct 26 16:59 pmBitter LakeSeattle, WA 98133TacomaFri Oct 30 16:58 pmSeattleBellevuePuyallopDisposed atBitter LakeSeattle, WA 98133Mt. Rainier National ParkTraveled337 MilesCategoryShoe106–107 MIT Senseable City Lab Trash TrackEn RouteLongviewGifford Pinchot National ForestOld SneakerLast seen at:Mon Nov 2 8:35 amColumbia Ridge landfillArlington, OR 97812Sat Oct 31 0:58 amPortland

view of the removal chain that advances theunderstanding of its processes and potentialweaknesses; and to raise public awareness byilluminating a process that we rely on greatly,but understand poorly.On all three levels, the project made substantialcontributions. On the technical end, wedeveloped a tracking tag that can survive forextended periods of time in waste streams, andcan operate on a global scale using infrastructurethat is available everywhere. In severaliterations, we developed a packaging strategythat protected the sensors and kept them firmlyattached to tracked waste. Trash Track alsogenerated a data set that presents a unique, integratedview of the system, its full reach, andthe companies involved. Finally, judging by thefeedback we received from the public, the projectcreated a vivid representation of a processthat is usually hidden and unobservable. Wehope that future researchers and institutionscan build on our experiences and use TrashTrack to advance our understanding of the cityand its improvement.Overall, the project targets a shortcomingin the waste removal system by generatinginformation that has not been available before.It allows the potential for investigating the fateof individual discarded items and touches on issuesrelated to transportation logistics, volumeand waste movement. While this informationhelps us to better understand how the networkcan be managed, a key aspect remains theproject’s impact on the public, the feedback tothe private individual. If we know where ourtrash goes and how long it takes to get there,will it have an impact on our future productionof waste?AcknowledgementsWaste Management was the main partner and sponsor ofTrash Track throughout all phases of the project. SeattlePublic Utilities, Qualcomm, and Sprint provided close technicalsupport in setting up and running the experiments. Boththe Architectural League of New York, who originally commissionedthe project, and The Seattle Public Library hostedexhibitions of Trash Track results. The Seattle Central Librarywas a crucial home base for all of our activities in Seattle.Notes1. Bay Area Rapid Transit, “BART - For Developers,” 2008,http://www.bart.gov/schedules/developers/index.aspx.2. New York City Government, “311 Online,” 2010, http://www.nyc.gov/apps/311/.3. O. Okolloh, “Ushahidi, or ‘testimony’: Web 2.0 tools forcrowdsourcing crisis information,” Change at Hand: Web 2.0for Development (2009): 65.4. Mark Weiser, “The computer for the 21st century,”Scientific American (September 1991): 94-104.5. J. Bleecker, Why Things Matter: A manifesto for networkedobjects–cohabiting with pigeons, arphids and Aibos in theInternet of Things (Near Future Laboratory, http://www. nearfuturelaboratory.com/files/WhyThingsMatter. pdf, 2005).6. Katharina Kummer, International management of hazardouswastes: the Basel Convention and related legal rules(Oxford University Press, 1999).7. Greenpeace International, “Following the e-wastetrail - UK to Nigeria,” 2008, http://www.greenpeace.org/international/photosvideos/greenpeace-photo-essays/following-the-e-waste-trail.8. Curtis C. Ebbesmeyer et al., “Tub Toys Orbit thePacific Subarctic Gyre,” Eos 88, no. 1 (January 2, 2007):TRANSACTIONS AMERICAN GEOPHYSICAL UNION.9. Eric Paulos and Tom Jenkins, “Urban probes: encounteringour emerging urban atmospheres,” in Proceedings of theSIGCHI conference on Human factors in computing systems(Portland, Oregon, USA: ACM, 2005), 341-350, http://portal.acm.org/citation.cfm?id=1054972.1055020.10. Bruce Sterling, Shaping Things (MIT Press, 2005).11. Seattle Public Utilities, “Seattle Public Utilities --Services,” n.d., http://www.cityofseattle.net/util/Services/index.asp.12. Office of Solid Waste, Electronics Waste Managementin the United States: Approach 1, Final (United StatesEnvironmental Protection Agency, July 2008).13. Frank Kreith and George Tchobanoglous, Handbook ofsolid waste management (McGraw-Hill Professional, 2002).References— Bay Area Rapid Transit. 2008. BART - For Developers;http://www.bart.gov/schedules/developers/index.aspx.— Bleecker, J. 2005. Why Things Matter: A manifesto for networkedobjects–cohabiting with pigeons, arphids and Aibosin the Internet of Things. Near Future Laboratory,http://www. nearfuturelaboratory. com/files/WhyThingsMatter. pdf.— Ebbesmeyer, Curtis C., W. James Ingraham, ThomasC. Royer, and Chester E. Grosch. 2007. Tub Toys Orbitthe Pacific Subarctic Gyre. Eos 88, no. 1 (January 2):TRANSACTIONS amERICAN GEOPHYSICAL UNION.doi:10.1029/2007EO010001.— Greenpeace International. 2008. Following the e-waste trail - UK to Nigeria. http://www.greenpeace.org/international/photosvideos/greenpeace-photo-essays/following-the-e-waste-trail.— Kreith, Frank, and George Tchobanoglous. 2002. Handbookof solid waste management. McGraw-Hill Professional.New York City Government. 2010. 311 Online. http://www.nyc.gov/apps/311/.— Office of Solid Waste. 2008a. Electronics WasteManagement in the United States: Approach 1, Final. UnitedStates Environmental Protection Agency, July.———. 2008b. Municipal Solid Waste in the United State:2007 Facts and Figures. United States EnvironmentalProtection Agency, November.— Okolloh, O. 2009. Ushahidi, or ‘testimony’: Web 2.0 toolsfor crowdsourcing crisis information. Change at Hand: Web2.0 for Development: 65.— Paulos, Eric, and Tom Jenkins. 2005. Urban probes:encountering our emerging urban atmospheres. InProceedings of the SIGCHI conference on Human factors incomputing systems, 341-350. Portland, Oregon, USA: ACM.doi:10.1145/1054972.1055020. http://portal.acm.org/citation.cfm?id=1054972.1055020.— Seattle Public Utilities. n.d. Seattle Public Utilities --Services. http://www.cityofseattle.net/util/Services/index.asp.— Sterling, Bruce. 2005. Shaping Things. MIT Press.— Weiser, Mark. 1991. The computer for the 21st century.Scientific American (September): 94-104.108–109 MIT Senseable City Lab Trash Track