Chapter I: Environmental and Regulatory Concerns at the Shooting ...

BMP for Lead at Outdoor Shooting RangesLow permeability reduces the amount ofhistorical leaching and increases the probabilityof the presence of basic (+pH increasing)minerals that can precipitate out of solution ingroundwater or cause the lead to bond to theclay. All of the basic calcium and relatedminerals generally will have been removed fromthe clean silica sand and gravel soils, so thelead in solution in groundwater in these typesoils can move long distances (miles) throughthe ground relatively unchanged.Soil Chemistry - The more basic minerals likecalcium and magnesium that are present in soilsalong the pathways through which thegroundwater moves, the greater the leadprecipitation (removal) rate. Lead should movein solution only a short distance (a few feet)through a sand composed of calcium shellfragments, but could move in solution longdistances (miles) through clean quartz sand.Depth to Groundwater - In areas ofgroundwater discharge such as river flood plainsand most flat areas, the groundwater surface isoften a few feet below the surface. Remember,the shorter the distance traveled, the greater therisk that the lead will migrate into theenvironment. Shallow depth to groundwater isindicative of higher risk for lead to reach thewater.pH of Groundwater - Although other factorsinfluence solubility of lead in water, a good rule ofthumb is that lead will precipitate out of solutionwhen the pH or alkalinity of water is greater thenabout 7.5. But, lead dissolved in acidgroundwater may travel many miles withoutchange.Health Effects of Lead Exposure on RangesLead poisoning is a serious health risk. Athigher concentrations, it is dangerous to peopleof all ages, leading to convulsions, coma andeven death. At even very low concentrations, itis dangerous to infants and young children,damaging the developing brain and resulting inboth learning and behavioral problems. Figure 1-1 describes the effects of exposure to lead onchildren and adults.Federal, state and local actions, including banson lead in gasoline, paint, solder and many otherlead-containing products, have resulted insignificant reductions in average blood-leadlevels. Despite these advances, the number oflead-poisoned children remains alarmingly high.Children living in older homes may be exposedto lead in peeling paint or paint dust. Childrencan also come in contact with lead in soil andwith lead dust carried home on the clothing ofparents.On ranges, inhalation is one pathway for leadexposure since shooters are exposed to leaddust during the firing of their guns. Becausewind is unlikely to move heavy lead particlesvery far, airborne dust is generally considered apotential threat only when there are significantstructures that block air flow on the firing line.Under such conditions, the hygiene and otherpractices proposed by the NRA for indoorshooting ranges in their “Source Book” areapplicable to outdoor ranges.Range workers may also be exposed to leaddust while performing routine maintenanceoperations, such as raking or cleaning out bullettraps. Owners/operators may want to protectthese workers by requiring them to wear theproper protective equipment or dampening thesoil prior to work.Another exposure route for lead at outdoorranges is ingestion by direct contact with lead orlead particles. For example, lead particlesgenerated by the discharge of a firearm cancollect on the hands of a shooter. Theseparticles can be ingested if a shooter eats orsmokes prior to washing his/her hands aftershooting. The relative risk of lead exposure topeople in a well managed facility is low.Detrimental effects due to elevated lead levelscan also be found in animals. Excessiveexposure to lead, primarily from ingestion, cancause increased mortality rates in cattle, sheepand waterfowl. For example, waterfowl andother birds can ingest the shot, mistaking it forfood or grit. Waterfowl, in particular, are highlysusceptible to lead ingestion. This is a concernat ranges where shooting occurs into or overChapter I - Page I-4