PUBLIC HEALTH ASSESSMENT
LAKE CITY ARMY AMMUNITION PLANT
[(a/k/a LAKE CITY ARMY AMMUNITION PLANT (NORTHWEST LAGOON)]
INDEPENDENCE, JACKSON COUNTY, MISSOURI
The Agency for Toxic Substances and Disease Registry (ATSDR) prepared this public healthassessment (PHA) to evaluate exposure pathways and to respond to community concerns about past,current, and potential future exposures to contaminants originating at Lake City Army AmmunitionPlant (LCAAP). After considering the most currently available information, ATSDR found thatcontaminant releases at LCAAP do not pose a public health hazard. ATSDR has categorized thissite as a "No Apparent Public Health Hazard" because exposure to contaminants in groundwaterand from air emissions in the past may have occurred (see definition in Table 1).
LCAAP is an active plant covering approximately 3,955 acres in Jackson County, Missouri.LCAAP, originally called Lake City Arsenal, has been in continuous operation since 1941, exceptfor a 5-year period between World War II and the Korean War. The plant was originally establishedas a government-owned, contractor-operated military installation to produce small caliberammunition. LCAAP is entirely fenced and access to the plant is restricted.
A number of chemicals are used in the plant's production process including detergents, bleaches,explosive compounds (e.g., lead azide and lead styphnate), petroleum and lubricating oils, andtrichloroethylene (TCE) and other solvents. Previous wastewater treatment and solid waste disposalpractices at LCAAP relied on unlined lagoons, landfills, and burn pits. These past practices resultedin contamination of soil, groundwater, and some surface water bodies at the plant.
ATSDR conducted a site visit at LCAAP in 1999. ATSDR viewed the areas of contamination, metwith LCAAP representatives, and gathered information used to evaluate potential public healthhazards from exposure to environmental contaminants. ATSDR did not identify any completedexposure pathways requiring immediate action. The primary community health concern involvespotential groundwater contamination and drinking water quality. In this PHA, ATSDR evaluatespotential exposures to groundwater, soil, surface water and sediment, and air.
Following a 1985 preliminary assessment/site investigation, LCAAP was divided into 33 studyareas. These areas are currently grouped into three operable units (OUs): the Area 18 OU, theNortheast Corner OU (Areas 11, 16, and 17), and the Installation-Wide OU, which includes allother study areas. The U.S. Environmental Protection Agency placed LCAAP on the NationalPriorities List of hazardous waste sites in 1987 because of groundwater contamination in Area 3.Each of the areas of contamination has been investigated. A final record of decision (ROD) for theArea 18 OU and an interim ROD for the Northeast Corner OU have been released. An interimremedial action ROD for metals contaminated soil for the Installation-Wide OU is expected to besigned in the Fall 2001. As of the release of this report, LCAAP has not proposed a schedule forcompleting a final ROD for the Installation-Wide OU.
ATSDR reviewed available on-site groundwater data. Chemicals in on-site monitoring wellsdetected at levels above ATSDR's health-based comparison values (CVs) include volatile organiccompounds (VOCs) (e.g., TCE, 1,2-dichloroethylene, and vinyl chloride), metals (e.g., lead,manganese, and arsenic), and some explosives (e.g., cyclotrimethylene trinitramine (royaldemolition explosives) [RDX] and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (high meltingexplosives).
Groundwater beneath LCAAP is used as a potable drinking water source. The plant obtains itsdrinking water from 13 active on-site supply wells. TCE and vinyl chloride have been and continueto be detected above their CVs in three of the plant supply wells. A former supply well, currentlybeing used as a groundwater extraction well, contained high levels of vinyl chloride and 1,2-dichloroethylene. Eight supply wells are currently connected to five air strippers, installed between1988 and 1990, that are designed to remove VOCs. Recent drinking water tests at LCAAP have metstate and federal standards for safe drinking water.
Although exposures to some VOCs may have occurred in the past, it is unlikely that theseexposures occurred at levels of health concern because most of the supply wells that were usedfor drinking water at LCAAP were not contaminated. No individuals consumed water exclusivelyfrom the supply wells that were found to contain VOCs. The water from all the supply wells isblended and stored in a large (500,000 gallon) holding tank where any VOCs would besignificantly diluted. ATSDR concludes that past exposures to on-site contaminants in drinkingwater supply wells posed no public health hazard. Because past exposure was possible,however, ATSDR has categorized this pathway as a "No Apparent Public Health Hazard." Onthe basis of currently available data and the ongoing water treatment, ATSDR concludes thatexposure to contaminants in on-site drinking water poses no current or future public healthhazards.
The Installation-Wide OU groundwater plumes are contained on site and are not expected to migratebeyond the plant's perimeter. The Area 18 OU and the Northeast Corner OU contain groundwaterplumes that are near or just beyond the northern perimeter of the plant. VOCs, lead, and cadmiumhave been detected in a few private wells located to the north of these source areas at levelsexceeding their CVs. ATSDR evaluated data from private drinking water wells and determined thatVOCs and metals have not been present at levels of health concern. On the basis of currentlyavailable data, ATSDR concludes that exposure to contaminants in private drinking water wellsposes no past, current, or future public health hazards. ATSDR has categorized this pathway asa "No Apparent Public Health Hazard" since exposure is still possible in the future.
ATSDR reviewed available on-site soil data. VOCs, metals, explosives, and polycyclic aromatic hydrocarbons were detected in surface soil above their CVs at some study areas. Access to the plant, however, is restricted and the small housing area located in the southwestern corner of the plant is isolated and distant from the main industrial area where the areas of contamination are located. Under LCAAPs Facility Use Contract initiative, any proposed new land use at the Plant must be reviewed by LCAAP and the Operations Support Command. In addition, any proposed reuse of land must meet existing legal agreements and conditions, including land use restrictions and institutional controls. In addition, state (MNDNR) and federal (EPA) regulatory agencies are responsible for making sure that contaminated areas meet the applicable clean-up standards for the proposed land use. On the basis of available data, ATSDR concludes that exposure to contaminants in soil poses no past, current, or future public health hazard.
ATSDR reviewed on-site surface water and sediment data. VOCs, metals, and explosives (e.g.,RDX) were detected above their CVs in some surface water and sediment samples. Most of thesurface water and sediment samples taken were in close proximity to sources of contaminationwhere exposures are unlikely to have occurred. Surface water and sediment samples collected offsite did not contain contaminants above CVs. From the available data, ATSDR concludes thatexposure to contaminants in surface water and sediment poses no past, current, or future publichealth hazards.
ATSDR also reviewed potential past exposures to air emissions from burning of explosive materials(i.e., wet pyrotechnics and propellant powder) and from VOC emissions from the sealing operationsunits at LCAAP. Exposures to VOCs and other air pollutants may have occurred in the past;however, there are no monitoring data to evaluate whether contaminants released into air werepresent at levels that were harmful. Most VOCs were released near thecenter of the plant, within the main industrial area, and it is unlikely that ambient air concentrationswould have been high enough to pose a health hazard to residents living at the housing area on siteor at off-site locations near LCAAP. At present, the sources of contamination either no longer existor measures have been taken to reduce emissions. Open burning of explosive materials stopped in1993 and VOC emissions are currently being controlled through source reduction measures. Forthese reasons, ATSDR concludes that air contaminants in and around LCAAP pose no publichealth hazard for past, current, or future exposures. For past exposures, ATSDR has categorizedthe air pathway as a "No Apparent Public Health Hazard" since exposures may have occurred in thepast.
|No Apparent Public Health Hazards|| |
A. Past exposure to on-site groundwater at LCAAP (i.e., drinking water supply wells)
B. Past, current, or future exposures to off-site groundwater (i.e., private drinking water wells)
C. Past exposure to ambient air contaminants at LCAAP
|No Public Health Hazards|| |
A. Current or future exposures to on-site groundwater at LCAAP (i.e., drinking water supply wells)
B. Past, current, or future exposures to soil contamination at LCAAP
C. Past, current, or future exposures to surface water and sediment at LCAAP
D. Current or future exposures to ambient air contaminants at LCAAP
Lake City Army Ammunition Plant (LCAAP) is an active plant covering approximately 3,955 acresin Jackson County, Missouri. The plant is located near the eastern boundary of the city ofIndependence and is approximately 3 miles north of Blue Springs, 2 miles southwest of Buckner, and adjacent to Lake City to the north (Figure 1). The plant is bordered to the west by MissouriState Highway No. 7 and to the east by private residences and agricultural land. The plant isbetween U.S. Highway 24 to the north and U.S. Highway 70 to the south. A narrow unpaved road,Heidelburger Road, runs along the northern boundary of the plant. There are also railroad tracksthat run along the northern perimeter of the plant.
LCAAP, originally called Lake City Arsenal, has been in continuous operation since 1941, exceptfor a 5-year period between World War II and the Korean War. The plant was originally establishedas a government-owned, contractor-operated military installation to produce small caliberammunition. The plant has been modified since World War II to produce larger ammunition.LCAAP is under the jurisdiction of the U.S. Army Industrial Operations Command. The operatingcontractor from 1941 to 1985 was Remington Arms. In November 1985, the plant operation wasassumed by Olin Corporation (Burns and McDonnell 1999). The current operating contractor atLCAAP is Alliant Techsystems, which assumed operations from Olin Corporation in April 2000 (G.Anderson, Installation Restoration Program (IRP) Project Manager, personal communication,February 8, 2001).
LCAAP is the largest producer of rifle and machine gun ammunition for the U.S. Army. Support areas for the plant include an environmental laboratory, wastewater treatment plant, firing ranges, a calibration laboratory, machine shop, pipe fitting shop, electric shop, and a wood shop (USACHPPM 1998). Access to LCAAP is restricted by an outer fence surrounding the entire plant and an inner fence surrounding the main industrial area, which includes the high explosives manufacturing areas. Army Reserve and National Guard training exercises have also taken place on site since the 1960s. Most training exercises are conducted at the firing ranges in the eastern section of the plant, located southwest of Veteran's Lake. The firing range is fenced and only authorized personnel are allowed access.
Chemicals that are used on site in the plant's production process include soaps, detergents, bleaches,hydrochloric acid, sulfuric acid, nitric acid, explosive compounds (e.g., lead azide and leadstyphnate), phosphate cleaners, petroleum and lubricating oils, and trichloroethylene (TCE) andother cleaning solvents. Previous wastewater treatment and solid waste disposal practices at LCAAPrelied on burn pits, unlined lagoons, and landfills. Past waste disposal practices resulted incontamination of soil, groundwater, and some surface water bodies at the plant. Current wastemanagement includes treatment through a permitted industrial wastewater treatment plant (IWTP)and disposal to an off-site Resource Conservation and Recovery Act permitted waste disposalfacility (EA Engineering 1994).
In 1980, an installation assessment (IA) of LCAAP was conducted to assess the environmentalquality of the plant with regard to use, storage, treatment, and disposal of hazardous substances, andto identify potential public health hazards (USACHPPM 1998). The IA included a preliminaryinvestigation of all past waste disposal sites and chemical releases and focused on seven areas withinthe plant which had previously been used for industrial waste storage, including landfills, chemicallaboratories, and an IWTP. Initial sampling indicated the presence of explosives, metals, volatileorganic compounds (VOCs), and related breakdown products in soil and groundwater (PlexusScientific Corp. 1996).
In 1985, the United States Army Toxic and Hazardous Materials Agency, as part of the Department of Defense's Installation Restoration Program, conducted a preliminary assessment/site investigation (PA/SI) at LCAAP. The PA/SI involved the installation of 24 groundwater monitoring wells and the analysis of 48 soil and water samples. All groundwater sample locations contained VOCs, semivolatile organic chemicals (SVOCs), explosives, and metals. As a result of finding silver in groundwater samples collected from Area 3 that exceeded the U.S. Environmental Protection Agency's (EPA) drinking water maximum contaminant levels, EPA placed LCAAP on the National Priorities List of hazardous waste sites in 1987 (EA Engineering 1989; USACHPPM 1998). In August 1987, LCAAP implemented a potable well sampling program which included monitoring of some off-site private drinking water wells (USATHAMA 1990).
Following the PA/SI, LCAAP was divided into 33 study areas. These areas are currently groupedinto three operable units (OUs): the Area 18 OU, the Northeast Corner OU (Areas 11, 16, and 17),and the Installation-Wide OU, which includes all other study areas. The remedial investigation hasbeen completed for the Area 18 OU and is still in progress for the Northeast Corner OU and for theInstallation-Wide OU. A record of decision (ROD) has been completed for the Area 18 OU and aROD for Interim Remedial Action has been completed for the Northeast Corner OU. An InterimRemedial Action ROD for metals contaminated soil for the Installation-Wide OU is scheduled to besigned in the Fall 2001. LCAAP is still working on developing a schedule for releasing a final RODfor the Installation-Wide OU. A more detailed description of eachof the 33 study areas (Figure 2) and their corresponding OUs is included in Table 2.
The Agency for Toxic Substances and Disease Registry (ATSDR) released a Preliminary HealthAssessment for LCAAP in January 1989. Based on limited available information at that time,ATSDR considered LCAAP to be of potential public health concern because of the risk to humanhealth from exposure to contaminants through groundwater, soil, and surface water pathways. Aspart of the public health assessment process, ATSDR conducted a site visit and met withrepresentatives from LCAAP in April 1999. During the site visit, ATSDR viewed the areas ofcontamination and gathered information. At the time, ATSDR did not identify any completedexposure pathways requiring immediate action. In July, 2001, ATSDR participated in a publicavailability session (PAS) at LCAAP. ATSDR extended the public comment period until July 26,2001 for the PHA so that community members would have an opportunity to provide any additional comments or concerns at the PAS.
ATSDR examines demographic information, or population information, to identify the presence ofsensitive populations, such as young children and the elderly, in the vicinity of a site. Demographicsalso provide details on residential history in a particular area, information that helps ATSDR assesstime frames of potential human exposure to contaminants. Demographic information for the site andresidential areas surrounding LCAAP is presented in this section.
Peak employment at the plant occurred during World War II, with over 20,000 employees.Sincethen, the number of people employed at LCAAP has diminished considerably. As of April 2000,LCAAP employs approximately 700 people, nearly all are civilians (Plexus Scientific Corp. 1996).There are 11 dwellings located in the southwestern portion of the plant reserved for militarypersonnel. There are currently 51 residents living in this housing area and approximately 29 of theseindividuals are under the age of 18. This small housing area is on a hill and is separated from themain part of the plant by natural vegetation. An inner fence also separates the housing area from thehigh explosive production area in the south central part of the plant. Although a small number ofchildren reside in the housing area, there are no day care centers or schools located at the plant.
According to 1997 census estimates, the population of Jackson County, where LCAAP is located, isapproximately 648,000. According to the 1990 U.S. Census, however, there are less than 65 peoplewho live within a one mile radius of LCAAP. Two small residential communities, Lake City, to thenorth (population less than 25 with 10 occupied dwellings), and Buckner, to the northeast(population of approximately 3,000) are located near LCAAP.
LCAAP is entirely fenced and access is controlled by a guarded gate at the main entrance. Othergates around the plant are generally not open unless supervised by official personnel. The plantcontains 461 buildings and the industrial area occupies approximately 700 acres of flat land locatedin the central portion of the plant (USACHPPM 1998).
LCAAP lies within the Osage Plains Section of the Central Lowlands Physiographic Province. Thisarea is characterized as a plain of low relief with broad stream valleys and flood plains of theMissouri River. It is underlain by nearly flat-lying, late Paleozoic sedimentary strata (EAEngineering 1994). The north and west portions of the plant are relatively flat areas whereas thesouth and east portions of the plant form uplands which have narrow crested ridges and 150 to 160feet of relief from valley floor to ridge top.
Approximately 520 acres in the northeastern part of LCAAP are maintained as an outdoorrecreation area. Veteran's Lake, covering 17 acres, is located within the recreation area and is usedfor fishing, hunting in specified areas, and mushroom harvesting. Efforts have been made to stockcatfish in Veteran's Lake. There are also many ponds scattered throughout the plant, some of whichmay be used for fishing. Deer and wild turkeys are two common species of wildlife that are found onthe plant's grounds. During the hunting season, the number of hunting permits is regulated andhunting is only allowed during normal non-operating hours of the plant, such as weekends andholidays. The recreation area is not located near any areas of contamination, however, because thearea is located within the overshoot of the ballistics firing range, camping is not permitted (USACHPPM 1998).
In preparing this PHA, ATSDR reviewed and evaluated information provided in the referenceddocuments. Documents prepared for the Comprehensive Environmental Response, Compensation,and Liability Act (CERCLA) and the Resource Conservation and Recovery Act (RCRA) programsmust meet specific standards for adequate quality assurance and control measures for chain-of-custody procedures, laboratory procedures, and data reporting. The environmental data presented inthis PHA are from site characterization, remedial investigation, and groundwater monitoring reportsprepared by the United States Army under CERCLA and RCRA. The validity of the analyses andconclusions drawn in this document are dependent on the availability and reliability of thereferenced information. ATSDR reviews data from site-related reports and evaluates whetherdetection limits are set at levels that are protective of public health. ATSDR also notes anyinconsistencies or problems with data collection or reporting and evaluates whether the informationis adequate to be used for making public health decisions. Based on our evaluation, ATSDRdetermined that the quality of environmental data available for most site-related documents forLCAAP is adequate to make public health decisions.
In this section, ATSDR evaluates whether community members have been (past), are (current), orcould be (future) exposed to harmful levels of chemicals. ATSDR's exposure evaluation process ispresented in Figure 3. As the figure indicates, ATSDR considers how people might come intocontact with, or be exposed to, contaminated media. Specifically, ATSDR determines whether anexposure could occur through ingestion, dermal (skin) contact with contaminated media, orinhalation of vapors, and also considers the likely length (duration) and frequency of the exposure.
If exposure was or is possible, ATSDR then considers whether chemicals were or are present atlevels that might be harmful to people. ATSDR does this by screening the concentrations ofcontaminants in an environmental medium (e.g., soil, water, air) against health-based comparisonvalues (CVs). CVs are chemical concentrations that health scientists have determined are not likelyto cause adverse effects, even when assuming very conservative/safe exposure scenarios. BecauseCVs are not thresholds of toxicity, environmental levels that exceed CVs would not necessarilyproduce adverse health effects. If a chemical is found in the environment at levels exceeding itscorresponding CV, ATSDR examines potential exposure variables and the toxicology of thecontaminant. ATSDR emphasizes that regardless of the level of contamination, a public healthhazard exists only if people come in contact with, or are otherwise exposed to, harmful levels ofcontaminated media.
Environmental data for potential exposure pathways have been reviewed by ATSDR. Following thestrategy outlined above, ATSDR examined whether human exposure to harmful levels ofcontaminants via these pathways existed in the past, exists currently, or could potentially exist in thefuture. ATSDR summarizes its evaluation of these exposure pathways in Table 3 and describes it inmore detail in the discussion that follows. To acquaint readers with terminology used in this report, alist of CVs and a glossary are included in Appendices A and B, respectively.
- ATSDR concludes that past exposures to groundwater at LCAAP pose no public healthhazard. In the past, drinking water for LCAAP has been supplied by 14 on-siteproduction wells. VOCs have been detected in some of the plant's drinking water supplywells, however, they did not occur at levels that would cause adverse health effects.Because some exposure was possible, ATSDR has categorized past exposures togroundwater at LCAAP as a "No Apparent Public Health Hazard."
- Exposure to on-site groundwater poses no current or future public health hazard atLCAAP. With the exception of on-site housing units, which are connected to the city ofIndependence municipal water system, drinking water for LCAAP is currently supplied by13 on-site supply wells, eight of which are currently connected to air strippers that aredesigned to remove VOCs. One former supply well is now used as a water extraction andrecovery well. Recent drinking water monitoring test results meet state and federal safedrinking water standards.
- Groundwater plumes located in the Area 18 OU and the Northeast Corner OU are very close to the plant's fence line and some low levels of VOCs, explosives, and metals have been detected in private wells to the north of the Area 18 OU and the Northeast Corner OU. Results of routine groundwater monitoring of northern perimeter wells and off base wells north of LCAAP during 1998 and 1999 did not indicate the presence of VOCs at levels of health concern. The nature and extent of groundwater contamination north of LCAAP should be further characterized in order to evaluate the potential for the groundwater plumes to migrate off site. Currently, a groundwater extraction system pumps groundwater from underneath LCAAP and is designed to contain contaminated plumes on site. Construction of a permeable reactive wall (PRW) was completed in Fall 2000 in the Northeast Corner OU. The PRW is designed to filter VOC contaminants as groundwater passes through the permeable wall. Based on monitoring well data and remedial activities at LCAAP, ATSDR concludes that off-site drinking water wells pose no past, current, or future public health hazards. Because any potential exposure that might occur would be to levels of contaminant not expected to present a public health hazard, ATSDR has categorized past, current, and future exposures from off-site drinking water wells as a "No Apparent Public Health Hazard."
Physical Characteristics and Hydrogeology
Generally, LCAAP groundwater flows to the north and northwest. However, a groundwater flowdivide exists in the central portion of LCAAP as a result of pumping of groundwater fromproduction wells. During groundwater investigations at LCAAP, a model was developed to helpconceptualize how groundwater flows underneath LCAAP. The model identifies threehydrostratigraphic units (HUs) (HU1, HU2, and HU3) (EAEngineering 1994):
- HU1-- This unit extends from the ground surface to a depth of approximately 20 to40 feet below the ground surface (bgs) and is comprised of a silty clay and fine sand.
- HU2 -- This unit is approximately 40 to 50 feet thick and is present from 20 to 40feet bgs to a maximum depth of 80 to 90 feet bgs. It is comprised of fine to coarsesand and fine to coarse gravel with a variable silt content. This unit has a very goodability to transmit water and is the primary aquifer in the area. HU2, often referred toas the Lake City Aquifer, provides nearly 1.2 million gallons of water per day to theplant.
- HU3 -- This unit exists below a depth of 90 feet bgs and is made up of shale andlimestone from the bedrock underlying the residual soil in the uplands and the sediment in the valley. This unit has a poor ability to transmit water (EAEngineering 1994).
HU1, the shallowest unit, covers most of the plant. The horizontal hydraulic gradients in HU1 arestrongly influenced by both topography and the surface water drainage ditches. These ditches wereconstructed in areas of natural drainage depressions in order to control flooding. HU1 is alsoaffected by the withdrawal of groundwater from the deeper HU2 aquifer (EA Engineering 1998a).
A large portion of LCAAP, primarily the western and northeastern portion, is situated in a valleywhere the water table is very shallow. The far west and southwestern portion of the plant consistsprimarily of uplands. The valley consists of HU1, HU2, and HU3, whereas the uplands generallyonly contain HU1 and HU3. The major difference between the two areas is that the groundwaterflow in the uplands is strongly influenced by topography and the flow in the valley is primarilycontrolled by pumping of the water supply and recovery wells (Dames & Moore 1999).
The plant's potable and industrial water needs are provided by a series of 22 production wells.LCAAP currently obtains its drinking water from 13 active on-site supply wells. All drinking watersupplied by on-site production wells is screened in the HU2 aquifer at approximately 90 feet bgs.Eight of the 13 water supply wells are currently connected to five air strippers that remove most ofthe VOCs prior to distribution (Dames & Moore 1999; F.J. Abshier, Olin Corporation, WinchesterDivision, personal communication, October 26, 1999). The air strippers were installed between1988 and 1990. After the raw water is processed through the air strippers, groundwater is pumpedthrough an aerator to a clarifier, where lime (to achieve optimal pH for water softening) and alum (acoagulant) are added. The water then flows through sand filters for removal of suspended solids. Thewater is chlorinated and the finished water from all 13 supply wells is collected in a 500,000 gallonholding tank where the water is blended prior to distribution (USACHPPM 1998)(W. Melton,Environmental Engineer, LCAAP, personal communication, 1999). According to plant officials, theon-site housing units have been connected to the city of Independence municipal water supply forover 4 years (G. Kelso, Environmental Engineer, LCAAP, personal communication, June 29,1999).
The communities surrounding LCAAP rely mostly on groundwater for their drinking water supply. The residents living near LCAAP are supplied with municipal water primarily from one of three sources: 1) Jackson County residents living to the west, northwest, and southwest (Independence), south (Blue Springs), north (Lake City), and northeast (Buckner) of LCAAP obtain drinking water mostly from the city of Independence water department, which obtains water almost entirely from groundwater supplies; 2) some residents living north and northeast of LCAAP obtain their water from the Kansas City Water Services, which uses about half groundwater and half surface water from the Missouri River about 8 miles to the north of LCAAP; and 3) a small number of residents living southeast and east of LCAAP get municipal water from the Jackson County public water supply, which purchases most of its water from the Kansas City Water Services or the city of Independence water department (MDNR 1999). A small number of residences north of LCAAP also rely on private wells for their drinking water. Most of the private wells to the north of the plant draw water from the Lake City Aquifer.
Nature and Extent of Groundwater Contamination
On-Site Groundwater Contamination
Results of 1999 quarterly and annual monitoring of drinking water from LCAAP's water supplyplant (treated water prior to distribution) showed that vinyl chloride (0.9 parts per billion [ppb])slightly exceeded ATSDR's health-based CV of 0.7 ppb. Four other chemicals exceeding CVs,bromodichloromethane (BDCM) (6.2 ppb), bromoform (5.0 ppb), bromomethane (69.6 ppb), anddibromochloromethane (CDBM) (9.3 ppb), were present in the finished water (Continental 1999a;1999b). BDCM, bromoform, bromomethane, and CDBM are not chemicals associated with theroutine operations at LCAAP. These chemicals are common by-products of chlorination. Chlorine isadded to drinking water to kill disease-causing organisms (ATSDR 1989, 1990, 1992).
TCE and other VOCs have been detected in several of the plant's 13 drinking water supply wellsprior to being processed by air strippers. During 1998-1999, TCE (34 ppb) was detected in supplywell 17-AA (located within Area 12) above its CV. One sample at supply well 17-K (Area 22) andthree samples at supply well 17-P (Area 14) contained vinyl chloride (8 ppb) above its CV. Onesample collected in November 1998, at supply well 17-JJ (located near the center of the plant),contained tetrachloroethylene (PCE) (1.7 ppb), slightly above its CV (Dames & Moore 1999;Dames & Moore 2000).
Results of samples collected from 1990 to 1997 indicate that three of the 13 active water supplywells (17-AA, 17-K, and 17-P) contained levels of contaminants above CVs. TCE (52 ppb) wasdetected above its CV in well 17-AA and the levels appeared to be relatively stable from 1990through 1997. Water from this supply well was not drawn from extensively in the past because of itshigh mineral content (F.J. Abshier, Olin Corporation, Winchester Division, personalcommunication, October 26, 1999). Vinyl chloride (8 ppb) was detected above its CV in wells 17-Kand 17-P. Vinyl chloride was detected only once in well 17-K (Dames & Moore 1999). One supplywell (17-FF) was converted to a water extraction and recovery well in 1998 and is currently beingused to remove VOCs. Samples collected from this well, prior to its conversion, contained 1,2-dichloroethylene (1,2-DCE) (380 ppb) and vinyl chloride (270 ppb) (Dames & Moore 1999).
LCAAP routinely samples and analyzes groundwater from about 150 monitoring wells across the plant. However, as many as 222 wells (including production wells and off-site wells) have been sampled as part of past environmental investigations (EA Engineering 1994). VOCs, SVOCs, explosives, metals, and some radionuclides were detected in groundwater in several areas of the plant. Some VOCs were detected in groundwater at levels above CVs. Groundwater sampling in the Northeast Corner OU (Areas 16 and 17) and in the Area 18 OU have identified VOC plumes that extend to the northern perimeter of the plant. The nature and extent of contamination beyond the northern plant boundary has not been fully characterized and it is possible that some groundwater contamination has migrated off site. Other VOC plumes have been identified in areas near the west and northwest portion of the plant, in Areas 7 and 12, and in Area 8 in the southwestern portion of the plant, which are part of the Installation-Wide OU. Sampling results reported in 1994 identified 1,2-DCE as the most common chlorinated compound detected in the groundwater at LCAAP (EA Engineering 1992).
At the Northeast Corner OU, 1,2-DCE was detected at concentrations as high as 300,000 ppb in theimmediate vicinity of the solvent pits and as high as 1,000 ppb within 400 feet downgradient of thesolvent pits. Two VOCs, TCE (87 ppb) and PCE (8.1 ppb), and two metals, lead (26 ppb) andcadmium (21 ppb), were detected above their CVs in the HU2 aquifer in the Northeast Corner OU(EA Engineering 1995a, 1998a).
Samples collected from the Area 18 OU monitoring wells contained several VOCs, vinyl chloride(8,000 ppb), 1,2-DCE (4,000 ppb), TCE (68 ppb), benzene (42 ppb), 1,1-dichloro- ethylene (1,1-DCE) (35 ppb), and PCE (8.1 ppb), that exceeded their CVs. The highest VOC concentrations werefound in the intermediate and deep monitoring well samples (50 - 90 feet deep) of HU2. In three ofthe shallow monitoring wells in HU2 (upper 30 feet), four VOCs, carbon tetrachloride (44 ppb),vinyl chloride (20 ppb), 1,1-DCE (15 ppb), and chloroform (8.8 ppb), were detected at levels abovetheir CVs. Two metals, manganese (2,740 ppb) and arsenic (16.8 ppb), were also detected abovetheir CVs (EA Engineering 1995b, 1998b).
Samples collected from the Installation-Wide OU monitoring wells contained VOCs and othercontaminants, including metals, explosives, and some radiological activity. In Area 8, 1,2-DCE (93ppb) and TCE (15 ppb) were detected above their CVs. Lead was detected above its CV at manysampling locations and the maximum concentration (4,900 ppb) was found in a shallow well inArea 2. This is likely due to the proximity of the well to an inactive wastewater treatment lagoonwhere high levels of lead in soil were detected. Cyclotrimethylene trinitramine (royal demolitionexplosive) (RDX) (1,200 ppb) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (high meltingexplosive) (3,600 ppb) were the most prevalent explosives detected within the Installation-Wide OUabove their CVs. Both alpha and beta radioactivity were detected above their CVs in Area 10 OU(firing range waste dump). The area is currently undergoing cleanup activities for depleted uraniumwhich is being overseen by the Nuclear Regulatory Commission (USACHPPM 1998).
Off-Site Groundwater Contamination
LCAAP has installed eight off-site monitoring wells. The VOC plume associated with the Northeast Corner OU (Areas 16 and 17) has reached off-site monitoring wells to the north. These wells are connected to air strippers that remove VOCs. Three groundwater extraction wells located in the Area 18 OU pump water to an air stripper and help prevent VOCs from migrating beyond the plant perimeter. Removing the groundwater creates a cone of depression underneath the plant and prevents most off-site migration (F.J. Abshier, Olin Corporation, Winchester Division, personal communication, October 26, 1999). The water is subsequently treated in the Area 18 OU pump and treat system prior to being discharged to the Little Blue Valley Sewer District (USACHPPM 1998; W. Hills , Division of Environmental Quality, Missouri Department of Natural Resources, personal communications, October 18, 1999).
Twelve residential wells were sampled by LCAAP as part of a quarterly monitoring programconducted from July 1988 through September 1993 (EA Engineering 1995b). Low levels of VOCsand explosives were occasionally detected during this monitoring period. In November 1989, 1,1-DCE (2 ppb), benzene (1.1 ppb), and TCE (3.1 ppb) were detected at levels slightly above theirCVs; in January 1992, chloromethane (7.8 ppb) was detected in one well slightly above its CV; inDecember 1992, TCE (6.4 ppb) was detected above its CV in one well; in March 1993, two samplesexceeded state and federal safe drinking water standards of 5 ppb (SDWS) for cadmium (8.9 ppb);and in September 1993, one sample slightly exceeded SDWS of 15 ppb for lead (15.9 ppb)(USACHPPM 1998; EA Engineering 1995b; Flatwater Group 2001). The source of the cadmiumand lead in off site private wells is not known, however, cadmium (15 ppb) has been detected inmonitoring wells (MW 99-5 and MW 99-6) near the northern boundary and lead and cadmium havebeen detected in soil at LCAAP; (EA Engineering 1994; Dames and Moore, 2000). In March 1998, six residential wellswere sampled by the Missouri Department of Health. The results of these tests did not show anycontaminants exceeding CVs (MDOH 1998).
Results of drinking water quality monitoring tests conducted in 1998 for the city of Independencewater department and in 1999 for Kansas City Water Services Athierton water treatment plant didnot identify any compounds that exceeded SDWS. These are the two primary drinking watersuppliers for the areas around LCAAP. All municipal water departments in Jackson Countyroutinely test their water supplies to ensure that they are in compliance with state and federalrequirements (City of Independence Water Department 1998; Kansas City Water Services 1999).
Evaluation of Potential Public Health Hazards
On-site - It is possible that prior to air strippers being installed at the plant, individuals may haveconsumed water from supply wells that contained levels of VOCs above ATSDR's health-basedCVs. Past water sampling data have detected VOCs in excess of CVs in four water supply wells.Vinyl chloride has occasionally been detected at levels slightly above its CV in two supply wells(17-K and 17-P) and TCE has been consistently detected above its CV in one supply well (17-AA).Recovery well 17-FF was used as a supply well prior to 1998 and contained 1,2-DCE and vinylchloride above their CVs.
When estimating the health significance of an exposure pathway, ATSDR estimates exposure dosesand compares the values to standard health guidelines. In calculating human exposure doses,ATSDR made very conservative assumptions about the frequency and duration of exposure.ATSDR also assumed that LCAAP workers and on-site residents would be exposed to the maximumcontaminant concentrations detected. These assumptions are often necessary because ATSDR doesnot know with certainty when contaminants first reached supply wells or how much contaminationwas present at the time water was being consumed from these wells. These assumptions likelyoverestimate actual exposure because workers are not likely to obtain most of their drinking waterfrom LCAAP and the small number of individuals who have lived in the on-site housing areagenerally only reside there for a short period of time. Moreover, individuals at LCAAP are notlikely to be exposed to these maximum concentrations because water from all supply wells isblended and stored in a large holding tank. The methods and assumptions used to estimate exposuresand evaluate potential health effects are described in greater detail in Appendix C.
Since no individual well at LCAAP ever supplies all the drinking water for LCAAP and no oneperson drinks exclusively from one supply well at the maximum contaminant concentration,ATSDR concluded that past exposure to the LCAAP drinking water supply poses no public healthhazard.
Off-site - Results of off-site groundwater monitoring tests and residential private well monitoringindicate that some VOCs, explosives, and metals, mostly at low levels, have migrated beyond theplant's perimeter in the north central portion of the plant, which includes the Area 18 OU and theNortheast Corner OU. A few contaminants, benzene, TCE, and 1,1-DCE, were detected at levelsslightly above their CVs.
ATSDR evaluated exposures to private well water by off-site residents using the same conservativeapproach described above (see Appendix C). Based on this evaluation, ATSDR concluded thatdrinking water from these private wells does not pose a past health hazard because contaminant concentrations are too low to cause adverse health effects.
Current and Future Exposures
On-site - A system is in place to remove VOCs from the groundwater underneath the plant. LCAAP is a state permitted public drinking water supply and testing of treated water in conjunction with that permit is conducted on a monthly basis for VOCs and some metals. Although untreated groundwater in some areas underneath LCAAP has exceeded safe drinking water standards, recent water monitoring results of the treated drinking water supply have met all state and federal drinking water standards. As long as LCAAPs drinking water treatment and monitoring program is in place, exposures to on-site drinking water from the supply wells at LCAAP pose no current or future public health hazards.
Off-site - Although low levels of some VOCs, explosives, and metals have been detected in privatewells to the north of the Area 18 OU and the Northeast Corner OU between, these contaminantswere mostly detected at levels below CVs. In 1992 eight groundwater monitoring wells wereinstalled just off site to the north of the Area 18 and the Northeast Corner OU. According to datapresented in the Annual Reports for LCAAP Comprehensive Groundwater Monitoring Program, these monitoring wells have not contained levels of VOCs that exceed EPA's maximum contaminantlevels (Dames and Moore 2000). A permeable reactive wall (PRW) has been constructed in Area16, which is designed to prevent further contamination of areas downgradient of the groundwaterplume (G. Anderson, IRP Project Manager, LCAAP, personal communication, February 8, 2001). Itis expected that the PRW and the groundwater extraction well, installed in 1998, at the northernboundary of the plant will prevent future off-site migration of contaminated plumes beneathLCAAP. Based on this information, it is unlikely that drinking water from these private wells willpose current or future public health hazards.
Soil at LCAAP does not pose a past, current, or future public health hazard. Surface soilcontamination, including VOCs, explosives, polycyclic aromatic hydrocarbons (PAHs),and metals, has been detected above ATSDR's health-based CVs in some areas ofLCAAP. Access to most of these areas is restricted and any exposures by visitors ortrespassers would likely be infrequent and of very short duration. LCAAP is in theprocess of out leasing part of the plant and, as a result, land use may change in thefuture. Surface soil contamination is being addressed by LCAAP through various interimremedial activities at each of the three OUs. These remedial activities shouldsignificantly reduce or eliminate the potential for harmful exposures to contaminants inthe future. According to LCAAP representatives, any proposed new land use at the Plantmust be reviewed by LCAAP and the Operations Support Command. Any reuse of landmust meet existing legal agreements and conditions, including land use restrictions andinstitutional controls in place at the time of the agreement. In addition, state (MNDNR) andfederal (EPA) regulatory agencies are responsible for making sure that contaminated areasmeet the applicable clean-up standards for the proposed land use. The potential forexposures from surface and subsurface soil contamination should be reevaluated if outleasing at LCAAP ever results in unrestricted use of contaminated source areas.
Surface and subsurface soil samples were collected from most of the designated areas of concern onsite. The primary soil contaminants, some of which exceed CVs for soil, are VOCs (e.g., TCE, PCE,vinyl chloride, and toluene), SVOCs, explosives (RDX is the most common explosive compounddetected), and metals (e.g., arsenic, lead, and chromium). The nature and extent of soilcontamination detected in each OU and corrective measures taken by LCAAP are summarized in thediscussion that follows and in Table 2.
Nature and Extent of Soil Contamination
- Northeast Corner OU
- Area 18 OU
- Installation-Wide OU
The Northeast Corner OU (Areas 11, 16, and 17) has a heavily contaminated oil andsolvents pit; a 17-acre abandoned landfill; an area that received waste glass, paints, andsolvents; and a contaminated burning ground. VOCs, SVOCs, metals, and explosives havebeen detected in both surface and subsurface soil, some above CVs. Most of thecontaminants exceeding their CVs were found at the oil and solvents pit in Area 17. VOCsdetected above CVs include TCE (2,000 ppm), PCE (420 ppm), 1,1,2-trichloroethane (62ppm), and vinyl chloride (50 ppm). PAHs detected above CVs include benzo(a)pyrene(2,000 ppm), benzo(a)anthracene (3,000 ppm), benzo(b)fluoranthene (5,000 ppm), andbenzo(k)fluoranthene (7,000 ppm). One metal, arsenic (50 ppm), was detected above its CV(EA Engineering 1998c).
A ROD for Interim Remedial Action at the Northeast Corner OU addresses the primarysource of soil contamination, the oil and solvents pits, located in Areas 16 and 17. Theremedial action to be implemented involves installing a 24-inch thick vegetated soil coverover the Area 17B oil and solvent pits to minimize migration of contaminants to nearbysoils. Institutional controls will also be implemented, including: 1) restriction of on-siteworker's access to contaminated soil; 2) filing a notice to the deed detailing the restrictionsof the continuing order to restrict on-site workers; and 3) a covenant to the deed in the event of a transfer of property (EA Engineering 1998a).
The Area 18 OU covers approximately 88 acres along the northern portion of the plant andconsists of earth pits used for disposal. VOCs detected above CVs include PCE (9,000 ppm)and TCE (1,000 ppm). The only metal detected above its CV was lead (1,600 ppm). Thefinal ROD for remedial action at the Area 18 OU requires excavating and disposing ofsurface soils containing lead above cleanup levels (1,000 ppm) as long as the soil does notcontain VOCs exceeding 10 ppb. The selected alternative in the ROD provided for on-siteremediation of Surface soils containing both lead and VOCs exceeding 10 ppb with multi-phase vapor extraction (MPVE) beneath a two-foot soil cover(EA Engineering 1998b). However, based on data collected subsequent to the release of theArea 18 ROD, VOC contamination may be more widespread than previously expected.LCAAP has proposed revising the Area 18 ROD because the MPVE system may not beeffective in addressing contamination in this area. LCAAP and regulators are considering the most appropriate corrective actions to be taken.
The Installation-Wide OU (consisting of 31 source areas) has a number of areas with surfaceand subsurface soil contamination. No VOCs were detected above CVs in surface soil. PAHswere detected in surface soils in Areas 22, 26, and 31. Total PAHs were detected in twosurface soil samples in Area 31 above 15,000 ppm. The metals detected above CVs insurface soil at LCAAP include antimony (1,120 ppm, source: Area 13), lead (110,000 ppm,source: Area 2), copper (140,000 ppm, source: Area 7), and zinc (200,000 ppm, source:Area 7). VOCs were primarily detected in subsurface soil in Areas 3, 7, 14, and 30,including toluene, ethylbenzene, PCE, TCE, and 1,1,1-trichloroethane. However, only PCE(37 ppm) was detected in Area 7 above its CV (EA Engineering 1994). Explosives were alsodetected in soil, primarily subsurface soil, but none were above CVs (EA Engineering 1992).
Evaluation of Potential Public Health Hazards
LCAAP is gated and access has always been restricted to the public. Most areas of contaminationare located in isolated sections of the plant not frequently accessed by individuals on site. Thehousing area at the plant is on a hill surrounded by vegetation and is not in close proximity to anyareas of contamination. There is an inner fence that separates the housing area from the explosivesarea. Children living in the housing area are restricted from going onto the plant. There have beenoccasional violations of these rules in the past by children living in housing on site, however, plantsecurity have strictly enforced these rules. Access to the industrial areas of LCAAP is restricted bythe inner fence and children would not ever have access to this area without being accompanied byan adult. For these reasons, exposure to contaminated soil did not pose a past public health hazard.
Current and Future Exposures
Soil remediation efforts at LCAAP include a proposed a plan for interim remedialaction for the Installation-wide OU which was released for public comment during the winter 2001(LCAAP 2001). A final ROD for remedial action at the Area 18 OU and a ROD for interimremedial action at the Northeast Corner OU have been released. Soilremediation of waste pits and other areas of contamination will reduce the likelihood of any currentor future exposures to individuals on site at LCAAP. Additional data collection and site evaluationmay be required for some of the 31 designated areas within the Installation-wide OU to bettercharacterize the nature and extent of contamination. LCAAP will not pose current or future healthhazards to the public as long as access to the plant continues to be restricted and future land uses donot allow development of contaminated areas until they meet all state and federal cleanupguidelines.
Surface water and sediment at LCAAP do not pose a past, current, or future public healthhazard. Contaminant levels were generally below CVs for surface water and sedimentsamples across LCAAP. A few contaminants were detected in close proximity to sourceareas above CVs. However, most water-related recreational activities on site take place on or near Veteran's Lake which is not very close to any areas of contamination.
Surface Water Use
LCAAP is located on a surface water divide. Surface water drainage originating from the western portion of the plant flows northwest toward West Fire Prairie Creek and eventually Little Blue River, less than 1 mile away. Drainage originating from the eastern portion of the plant flows northeast toward East Fire Prairie Creek and eventually into the Missouri River, approximately 5 miles away (EA Engineering 1994). There are four locations occupying a total of 5.58 acres at LCAAP that have been designated as wetland areas by theU.S. Army Corps of Engineers.
Surface water is not used as a source of drinking water for LCAAP or for most of the residential,commercial, and industrial areas located near the plant. The only surface water source of drinkingwater in the area is from the Missouri River located approximately 8 miles north of LCAAP (R.Maley, Missouri Department of Health, personal communication, October 19, 1999). Veteran'sLake is located in the northeast portion of the plant and is used for recreational activities such asboating and fishing. Swimming is not permitted at Veteran's Lake. There are a number of smallponds scattered across the plant, some of which are used for fishing.
Nature and Extent of Surface Water/Sediment Contamination
Metals, some explosives (e.g., RDX), and a few VOCs were detected above their CVs in some of thesurface water and sediment sampled in the areas of contamination. Most of the surface water andsediment samples taken were in close proximity to sources of contamination. VOCs detected insurface water above their CVs include TCE (21 ppb), chloroethane (90 ppb), bromodichloro-methane (5.22 ppb), and dibromochloromethane (3.38 ppb). Since access to the plant is restricted,exposure to sediment is unlikely for individuals located off site. Remedial activities are ongoing atLCAAP, thereby reducing the potential for individuals to be exposed to site-related contaminants inthe future.
Veteran's Lake was eliminated from further consideration as a source of contamination in the RIreport of the Installation-Wide OU released in 1994 because all compounds detected in surfacewater were comparable to background levels (EA Engineering 1994). In 1992, 1,2-DCE (27 ppb)and TCE (21 ppb) were detected in a surface water sample taken from Ditch B, in the Area 18 OU.Surface water from Ditch B eventually flows off site to the northeast toward East Fire Prairie Creek.In 1992, surface water and sediment samples were taken from three off-site locations, one of whichwas downstream of Ditch B. These samples did not contain concentrations of metals, explosives, or VOCs that exceeded CVs (EA Engineering 1994).
Evaluation of Potential Public Health hazards
Most of the contaminants detected in surface water and sediment across LCAAP were below CVs. On-site surface water is not used as a source of drinking water for LCAAP and any potentialexposures to on-site surface water and sediment would have been infrequent and of short duration.Most fishing and recreational activities at LCAAP are limited to Veteran's Lake. The closest area ofcontamination is over one-half mile to the northwest of this lake and the concentrations found are toolow to pose a health hazard. ATSDR concludes that past exposures to surface water and sediment did not pose a public health hazard.
Current and Future Exposures
Since most of the contaminants detected in surface water and sediment were below their CVs andremedial activities are ongoing at LCAAP, it is unlikely that individuals are currently being exposedor will be exposed in the future to site-related contaminants at harmful levels. Some VOCs werefound in surface water samples taken from Ditch B in the Area 18 OU. There is the potential forsurface water to runoff into East Fire Prairie Creek located northeast of the Area 18 OU; however, it is not likely that contaminant levels would be found at harmful levels. ATSDR concludes thatcurrent and future exposures to surface water and sediment do not pose a public health hazard.
No public health hazards are associated with past air exposures in and around LCAAP.Because exposure was possible, ATSDR has categorized this site as a"No ApparentPublic Health Hazard". No current or future public health hazards are associated withexposure to air contaminants at LCAAP. Exposures to VOCs and other air pollutants mayhave occurred in the past, however, there are no data to evaluate whether contaminantsreleased into air were present at levels that were harmful. Most VOCs were released near the center of the plant, within the main industrial area, andit is unlikely that ambient air concentrations would have been high enough to pose ahealth hazard to residents living at the housing area on site or at off-site locations nearLCAAP. Open burning/open detonation of explosive materials were conducted prior to1993. According to LCAAP officials, approximately 300 pounds of explosives materialswere burned per week, which was substantially below the permitted amount of 1,440pounds. LCAAP also minimized potential exposure to air contaminants off site by onlyconducting burns if certain whether conditions were met. VOCemissions from the sealing operations units are currently being controlled throughsource reduction measures, and the explosives waste incinerator (EWI) contains an airpollution control system.
Nature and Extent of Air Contamination
The principle sources of air emissions at LCAAP are the sealing operations units and the EWI(USACHPPM 1998). In addition, annual burning permits were previously issued to LCAAP foropen burning of wet pyrotechnics and propellant powder, open detonation of explosives, andexplosives demonstrations and testing. These operations ceased in April 1993 when the last openburning permit expired.
Historically, the sealing operations units, located in the central industrial area, have released some VOCs and other ozone depleting chemicals (e.g., ethyl acetate, methyl chloroform,ethyl alcohol, methyl ethylketone, and toluene). Severalprovisions to reduce ozone depleting chemicals and VOC emissions have been implemented atLCAAP. For example, water-based paint has been substituted for lacquer-based paint and biofiltershave recently been installed to reduce VOC emissions at the plant(USACHPPM 1998; P. Anthamattenn, LCAAP, Personal correspondence, March 1, 2001).
LCAAP operated the burning ground area for the open burning/open detonation of waste explosives,mixes, and powders. Burning activities, which took place from the middle 1950's until April 1993,were generally conducted once a week as long as specific weather conditions were met. According toLCAAP officials, the weather conditions required for open burning were mostly clear skies, windsless than 10 knots, and temperatures greater than 35 degrees. Open burning only took place between9:00 am and 4:00 pm (P. Anthamatten, LCAAP, Personal coorrespondence, March 22, 2001).
Based on historical information, approximately 300 pounds of materials per week were burned atLCAAP. The most common materials burned were propellant and wet explosive scrap (e.g., calciumresinate, magnesium, barium peroxide, polyvinyl chloride, and propellant powder). The permittedburn rate for these wastes could not exceed 240 pounds per day, every day for a maximum of 1,440pounds per week. Based on historical information, LCAAP was well under the permitted ratesaveraging about 60 pounds per day (P. Anthamattenn, LCAAP, Personal correspondence, March 1,2001).
The EWI is located near the center of the plant in Area 7. The incinerator contains an air pollutioncontrol system which removes particulate and hazardous organic waste constituents from exhaustgases and collects small particles in the baghouse. Cleaned exhaust is discharged into the atmospherethrough a 30-foot exhaust stack (USACHPPM 1998; U.S. Army Environmental Hygiene Agency1991). The stack is monitored routinely for carbon monoxide and nitrous oxide.
Evaluation of Potential Public Health Hazards
Some past activities at LCAAP may have resulted in the release of air contaminants near the source. Since air monitoring data from past operations at LCAAP are not available, ATSDR cannot determine whether exposures to levels of air contaminants above ATSDR's CVs occurred in the past. Most VOCs were released near the center of the plant, within the main industrial area, and it is unlikely that ambient air concentrations would have been high enough to pose a health hazard to residents living at the housing area on site or at off-site locations near LCAAP. According to correspondence from LCAAP officials, no unusual open burn/open detonation events or incidents took place and ATSDR is not aware of any complaints from residents living near LCAAP during the time period that open burning/open detonation occurred. For these reasons, ATSDR concludes that air contaminants in and around LCAAP pose no public health hazard for past exposures.
Current and Future Exposures
Current and future exposures to harmful levels of air contaminants are not expected because activities such as burning of explosives have been discontinued and sealing operations have been modified to reduce contaminant emissions. The EWI is not a significant source of air pollution at the plant because of its air pollution control system.
In order to identify the concerns of local residents, community interviews were conducted byrepresentatives of the United States Army Environmental Center, LCAAP, and Plexus ScientificCorporation in June 1995. Interviews were conducted with citizens living near the plant, as well ascommunity business and political leaders (Plexus Scientific Corp. 1996). The following healthconcern was expressed by residents:
- Concern about groundwater contamination in private drinking water supplies.
Environmental investigations have identified areas of groundwater contamination at LCAAP. Most of the groundwater plumes are contained on site and are not expected to migrate beyond theplant's boundary. The Area 18 OU in the north central part of the plant and the Northeast CornerOU contain groundwater plumes that may extend beyond the plant perimeter. Some private wells tothe north of LCAAP have been monitored. A couple of the wells sampled did contain levels of contaminants that were slightly above ATSDR's health-based CVs (See Evaluation of GroundwaterPathway Section and Appendix C). However, the samples collected did not contain harmful levels of contaminants and the water does not pose a public health hazard.
- Concern about allergies and other health effects (e.g., dizziness) resulting from pollution released from LCAAP.
As stated previously, some past activities at LCAAP may have resulted in the release of aircontaminants near the source. However, according to LCAAP officials, these releases have notexceeded amounts permitted by the state of Missouri. Additionally, most air contaminant releases at LCAAP are from the industrial area located near the center of the plant. Any pollutants migrating off site would be diluted and would not be expected to cause allergies or pose a health hazard.
ATSDR recognizes that infants and children may be more sensitive than adults to environmental exposure in communities faced with contamination of their water, soil, air, or food. This sensitivity is a result of the following factors: (1) children are more likely to be exposed to certain media like soil when they play outdoors; (2) children are shorter and therefore may be more likely to breathe dust, soil, and vapors close to the ground; and (3) children are smaller than adults and therefore may receive a higher dose of chemical exposure relative to their body weight. Children also can sustain permanent damage if exposed to toxic substances during critical growth stages. ATSDR is committed to evaluating children's special interests at sites such as LCAAP as part of its Child Health Initiative. ATSDR identified no situations in which children are likely to be exposed to harmful levels of chemical contaminants associated with LCAAP.
ATSDR evaluated the likelihood that children living at or near LCAAP may have been or may beexposed to contaminants at levels of health concern. The number of children living at the LCAAPhousing area is very small. The exact number is quite variable, but currently there are 23 childrenunder the age of 18 living at the LCAAP housing area. ATSDR determined that harmful exposuresare unlikely to occur because children living at this housing area do not have access to the mainplant where areas of contamination are located. There are no day care centers or schools located onsite and none are expected in the future. According to LCAAP officials, the housing area has beenconnected to the city of Independence water supply for approximately 4 years (G. Kelso,Environmental Engineer, LCAAP, personal communication, June 29, 1999). The primaryrecreational area at LCAAP, Veteran's Lake, is located at least one-half mile from any areas ofcontamination and it is unlikely that children who visit this recreational area would be exposed toharmful levels of contaminants. ATSDR did not identify any situations at LCAAP where children were likely to have been exposed to contaminants at levels which pose a health concern.
After evaluating available environmental information, ATSDR has drawn the following conclusions regarding media- and site-specific exposures:
- Exposure to on-site groundwater at LCAAP in the past poses no public health hazard.LCAAP, including the on-site housing area, has obtained drinking water in the past from14 on-site supply wells. VOCs have been detected in some of these supply wells aboveCVs. ATSDR evaluated these potential exposures and determined that these contaminantswere not in the LCAAP water supply at levels associated with adverse health effects.Because some exposure was possible, ATSDR has categorized past on-site groundwaterexposure as a "No Apparent Public Health Hazard."
- Exposure to on-site groundwater at LCAAP poses no current or future public healthhazard. Air strippers have been installed to remove VOCs from the groundwater. Thewater from 13 on-site supply wells is blended and stored in a 500,000 gallon holding tank.Recent monitoring tests going back to 1990 do not show contaminants exceeding their CVsin most of the supply wells. On-site drinking water at LCAAP meets state and federaldrinking water standards. The 11 on-site housing units are connected to the city ofIndependence water supply.
- Exposure to off-site groundwater poses no past, current, or future public healthhazard. Some off-site private wells located to the north of the Area 18 OU and theNortheast Corner OU contained VOCs that were mostly below ATSDR's health-basedCVs. VOCs that were detected above CVs in the private drinking water wells were notfound at levels that are associated with adverse health effects. A groundwater extractionwell is currently operating to contain the contaminated plume on site. Because someexposure was possible, ATSDR has categorized off-site exposure from private wells as a"No Apparent Public Health Hazard." ATSDR will revisit the site if new information ordata becomes available.
- Exposure to soil contamination at LCAAP poses no past, current or future public healthhazard. Access to the plant is restricted and any contact with contaminated soil by visitorsat the plant would likely be of short duration and would not result in harmful levels ofexposure. In addition, ongoing remedial activities at LCAAP, will further reduce thepotential for individuals to be exposed to site-related contaminants in the future. However,future plans of LCAAP may include outleasing parts of the land for private use. ATSDRmay need to reevaluate this exposure pathway if new site-related activities include morefrequent contact with contaminated soil.
- Exposure to surface water and sediment at LCAAP poses no past, current, or futurepublic health hazard. Most of the contaminants detected in surface water and sedimentwere below CVs and surface water is not a source of drinking water at LCAAP. Inaddition, ongoing remedial activities at LCAAP, will further reduce the potential forindividuals to be exposed to site-related contaminants in the future. It is unlikely,therefore, that individuals were exposed in the past, are currently being exposed, or will beexposed in the future to surface water contaminants at harmful levels.
- Air contaminants in and around LCAAP pose no public health hazard for pastexposures. Although no monitoring data are available, most VOCs and other air pollutantswere released near the center of the plant within the main industrial area. It is unlikely thatambient air concentrations would have been high enough to pose a health hazard toresidents living at the housing area on site or at off-site locations near LCAAP. Becausesome exposure was possible, ATSDR has categorized past exposures from air contaminantsas a "No Apparent Public Health Hazard."
- Exposure to air contaminants at LCAAP poses no current or future public healthhazard. Current and future exposures to harmful levels of air contaminants are unlikelybecause activities such as burning of explosives have been discontinued and sealingoperations, which generated VOCs and other air pollutants, have been modified to reducecontaminant emissions.
- ATSDR considers the groundwater, on-site soil, surface water and sediment, and airexposure pathways associated with LCAAP to pose no public health hazards.
The public health action plan (PHAP) for LCAAP contains a description of actions to be taken by ATSDR and/or other government agencies at and in the vicinity of the site upon completion of this public health assessment. The purpose of the PHAP is to ensure that this public health assessment not only identifies public health hazards, but provides a plan of action designed to mitigate and prevent adverse human health effects resulting from exposure to hazardous substances in the environment. The plan includes a commitment on the part of ATSDR to follow up and ensure that the plan is implemented. The public health actions completed and those to be implemented are as follows:
- LCAAP has completed a final ROD for interim remedial action at the Northeast CornerOU and a final ROD for remedial action at the Area 18 OU.
- Eight water supply wells have been connected to five air strippers at LCAAP.
- Private wells to the north of the Area 18 OU and Northeast Corner OU have been tested as part of a quarterly groundwater monitoring program.
Actions Ongoing or Planned
- ATSDR supports continuing routine (quarterly and annual) testing of the plant's drinking water supply wells for groundwater contaminants associated with LCAAP.
- A groundwater modeling effort is underway at LCAAP to characterize the extent ofcontamination and whether contaminated plumes are migrating off site. This will helpprovide future recommendations for operation of the plant's water supply.
- Soil remediation efforts are ongoing and final RODs have been or will be released toaddress other remedial actions (e.g., surface water, sediment, institutional controls) for each of the OUs.
- Some of the areas of contamination have interim control measures or land-use restrictions (e.g., prohibiting agriculture or grazing). ATSDR supports these remedial measures and recommends frequent monitoring of these activities to ensure they are in place for the period of time required by the RODs.
- A groundwater extraction and recovery system is operating in the Area 18 OU and isdesigned to contain the contaminated groundwater plume on site. ATSDR recommendscontinued routine monitoring of off-site groundwater contamination, downgradient of theArea 18 extraction system. In addition, new monitoring wells should be installed off site in any locations where data gaps may be occurring.
- As a precautionary measure, ATSDR recommends resuming routine monitoring of off-siteprivate wells to the north of the Area 18 OU and Northeast Corner OU.
- ATSDR recommends that LCAAP conduct routine (e.g., annual) surface water andsediment sampling of East Fire Prairie Creek and any other surface waters that flow off siteto ensure that contaminants from ditches and drainage canals in the Area 18 OU and theNortheast Corner OU are not entering the creek via surface water runoff.
- ATSDR recommends that any area(s) of the plant that is/are leased undergo a finalevaluation for environmental contamination to ensure that the area does not pose a public health hazard.
- ATSDR recommends that Area 25 (the Demolition Waste Dump) should be closelymonitored by plant security to ensure that children from on-site housing do not gain access.
Environmental Health Scientist
Federal Facilities Assessment Branch
Division of Health Assessment and Consultation
Gary Campbell, Ph.D.
Environmental Health Scientist
Federal Facilities Assessment Branch
Division of Health Assessment and Consultation
Agency for Toxic Substances and Disease Registry (ATSDR). 1989. Toxicological Profile forBromodichloromethane. December 1989.
ATSDR. 1990. Toxicological Profile for Bromoform/Chlorodibromomethane. December 1990.
ATSDR. 1992. Toxicological Profile for Bromomethane. September 1992.
Burns and McDonnell Engineers. 1999. Draft Installation-Wide Supplemental Field Investigation atthe Lake City Army Ammunition Plant, Independence, Missouri. April 1999.
City of Independence Water Department. 1998. 1998 Water Quality Chart Annual Report. 1998.
Continental Analytical Services, Inc. (Continental). 1999a. LCAAP Drinking Water SupplyQuarterly Testing Comparison Report. February 1999.
Continental. 1999b. LCAAP Drinking Water Supply Annual Testing Comparison Report. May1999.
Dames & Moore. 1999. Final 1998 Annual Report For LCAAP Comprehensive GroundwaterMonitoring Program. August 1999.
Dames & Moore. 2000. Final 1999 Annual Report For LCAAP Comprehensive GroundwaterMonitoring Program. August 2000.
EA Engineering, Science and, Technology, Inc. (EA Engineering) 1989. U.S. Army Toxic andHazardous Materials Agency (USATHAMA) Final Report: LCAAP Preliminary Assessment/SiteInvestigation. January 1989.
EA Engineering. 1992. Data Summary for the Area 8 OU, LCAAP. April 1992.
EA Engineering. 1994. Draft-Final Remedial Investigation Report of the Installation-Wide OperableUnit at Lake City Army Ammunition Plant, Independence, Missouri. Volume 1, Part I: Text.February 1994.
EA Engineering. 1995a. Remedial Investigation Report of the Northeast Corner Operable Unit atLake City Army Ammunition Plant. March 1995.
EA Engineering. 1995b. Remedial Investigation Report of the Area 18 Operable Unit at Lake CityArmy Ammunition Plant. January 1995.
EA Engineering. 1998a. Final Record of Decision for Interim Remedial Action at the NortheastCorner Operable Unit at Lake City Ammunition Plant (LCAAP), Independence, Missouri.September 1998.
EA Engineering. 1998b. Final Record of Decision for Interim Remedial Action at the Area 18Operable Unit at Lake City Ammunition Plant (LCAAP), Independence, Missouri. February 1998.
EA Engineering. 1998c. Draft Final Feasibility Study Report for the Northeast Corner OperableUnit at Lake City Ammunition Plant (LCAAP), Independence, Missouri. November 1998.
Flatwater Group. 2001. Database for off-site private well quarterly monitoring program conductedfrom 1987 through 1993. Data provided to ERG March 2001.
Kansas City Water Services. 1999. Water Services Laboratory Monthly Analysis of Athierton WellWater 1999. October 1999.
Lake City Army Ammunition Plant. 2001. Draft Proposed Plan for Interim Action Installation-WideOperable Unit. February 2001.
Missouri Department Natural Resources, Division of Environmental Quality. 1999. Inventory ofMissouri Public Water Systems 1999. January 1999.
Missouri Department of Health. 1998. Water Analysis Report for samples collected on March 2,1998.
Plexus Scientific Corp. 1996. Community Relations Plan (Final). December 1996.
U.S. Army Center for Health Promotion and Preventive Medicine. 1998. Environmental BaselineSurvey NO. 38-EH-8711-99 Lake City Army Ammunition Plant Independence, Missouri. October1998.
U.S. Army Environmental Hygiene Agency. 1991. Air Pollution Assessment No. 42-21-0475-91:Trial Burn for Deactivation Furnace Building 97, Lake City Army Ammunition Plant (LCAAP).February 19 through March 6, 1991.
U.S. Army Toxic and Hazardous materials Agency (USATHAMA), Environmental Assessment andInformation Sciences Division. 1990. Installation Restoration Program: Conceptual Program PlanFor Lake City Army Ammunition Plant (Final Report). December 1990.