PUBLIC HEALTH ASSESSMENT
LAKE CITY ARMY AMMUNITION PLANT
[(a/k/a LAKE CITY ARMY AMMUNITION PLANT (NORTHWEST LAGOON)]
INDEPENDENCE, JACKSON COUNTY, MISSOURI
| Site | Site Description/Waste Disposal History | Investigation Results/ Environmental Monitoring Results | Corrective Activities and/or Current Status | Evaluation of Public Health Hazard |
|---|---|---|---|---|
| Installation-Wide Operable Unit | ||||
| Area 1 Building 83 Wastewater Lagoons | Area 1 is located in the south-central portion of the plant. It is comprised of five unlined lagoons, used from the mid-1960s until 1988 to dispose of wastes generated during the production and neutralization of trinitroresorcinol . | Surface Soil: No surface soil sampling was conducted for this area. Groundwater: Surface Water: Sediment: Lead in one sample (858 parts per million [ppm]) was detected above its CV. | A remedial investigation (RI) has been completed. Four of the five lagoons were removed between 1986 and 1988 under an approved closure plan. | No public health hazard exists for groundwater, surface water, or sediment because access to the plant is restricted. There are no drinking water supply wells located in this area or in close proximity to the area of contamination. |
| Area 2 Building 85 Lagoons | Area 2 is comprised of several lagoons located near the south central edge of the plant. The original unlined lagoon, used from 1960 until 1972, was approximately 20,000 ft2. Two larger clay-lined wastewater lagoons operated from 1972 until 1980. All three lagoons accepted wastes from Building 85, used for the manufacturing, formulation, and loading of lead-based initiating compounds, including tetrazine and lead styphnate. | Surface soil: Lead was detected at levels well above its CV (107,523 ppm). Subsurface soil: Groundwater: | An RI has been completed. The two large clay-lined lagoons were removed in 1990. An interim remedial action is expected to be completed by December 2001 (G. Anderson, Installation Restoration Program (IRP) Project Manager, LCAAP, personal communication, June 26, 2000). | This site poses no apparent public health hazard. Access to this area is restricted. However, there may be a continuing source of lead and other metals from the original unlined lagoon which may eventually flow into the East Fire Prairie Creek via surface water runoff and may also be a potential source of groundwater contamination. |
| Area 3 Sand Pits | Area 3 is located in the northwest corner of the plant near the main gate. The area contains pits and lagoons that were used to dispose of sludge and demolition waste from the Industrial Wastewater Treatment Plant (IWTP) from the 1950s to the early 1970s. Heavy metals, oil and grease, volatile organic compounds (VOCs), and uranium metallic compounds were deposited in this area. | Soil: No contaminants were detected above their CVs in surface soil. Groundwater: | An RI has been completed. No further action is proposed for this site. | No public health hazard exists since no contaminants were detected above CVs in surface soil and access to the plant is restricted. Groundwater for the plant is processed by air strippers to remove VOCs prior to its distribution and tested on a monthly basis for VOCs and some metals. |
| Area 4 Building 139 Backline Ponds | Area 4 is located in the south-central portion of the plant and has been used to store neutralized waste from Building 139. Waste from the neutralization of lead styphnate slurry, treatment for lead azide contaminants, and neutralization of primer mixes and cyclotrimethylene trinitramine (RDX) were discharged to lagoons in the area. | Surface soil: Arsenic (9.92 ppm) was detected above its CV. Groundwater: One SVOC, B2EHP (13 ppb), was detected above its CV. Metals detected above their CVs include, antimony (68.2 ppb), barium (3,100 ppb), cadmium (34.4 ppb), chromium (335 ppb), lead (28 ppb), and nickel (29 ppb). Sediment: | An RI has been completed. The waste water lagoons were removed from 1985 to 1987 under an approved closure plan. No further action is expected for this site. | No public health hazard is likely to exist in this area from exposure to soil. Access to the plant is restricted. There may be some potential for surface water runoff. It is not expected to be an important source of contamination for any surface water bodies. There are no drinking water supply wells in this area. Groundwater for the plant is processed by air strippers prior to its distribution and is not expected to pose a public health concern. |
| Area 5 Explosives Surface Impoundments | Area 5 is located in the south-central part of the plant. The primary solid waste management unit (SWMU) is the surface impoundment 5A which is about 7 feet deep and covers an area approximately 210 ft x 140 ft. Neutralized wastewater at Building 139 was discharged into a lagoon. The lagoon operated from about 1941 through 1988. Waste materials include heavy metals, such as lead, cadmium, and antimony, and explosive compounds. | Subsurface soil: One metal, total arsenic (10.1 ppm), was detected at levels above its CV. Groundwater: | A preliminary assessment and site inspection (PA/SI) have been completed. Area 5 is currently undergoing a remedial investigation and feasibility study (RI/FS). | No public health hazard exists because the surface soil does not contain levels of contamination that would be harmful. Although the ground- water contains VOCs, there are no drinking water supply wells located in this area. Drinking water obtained from on-site supply wells contaminated with VOCs is processed by air strippers prior to its distribution. |
| Area 6 Building 65 Impoundments | Area 6 contains a surface impoundment approximately 151 ft x 162 ft. It is located just southeast of the center of the plant in the Fuze Line Manufacturing sector. Neutralized wastewater from Building 65, which is used for the packing of 20 mm cannon shells, was disposed of in this impoundment. It was closed in 1990. | Soil: No contaminants were detected above their CVs. Groundwater: | An RI has been completed. The surface impoundment was closed in 1990 under the Resource Conservation and Recovery Act in accordance with approved plans. | No public health hazard exists because the contamination source has been removed from the area and no contaminants have been detected above their CVs in surface soil. There are no drinking water supply wells located in this area. |
| Area 7 IWTP Lagoons | Area 7 is located just west of the center of the plant. It comprises several different SWMUs, including IWTP lagoons, a fuel oil spill area, a buried solvent pit, closed burning ground, and a container cleanup area. | Surface soil: Lead (1,000 ppm) was detected at levels above its CV. Groundwater: One SVOC, B2EHP (150 ppb) was detected above its CV. One explosive, RDX (1,800 ppb) was detected above its CV. Five metals, antimony (88 ppb), arsenic (110 ppb), cadmium (26 ppb), lead (61 ppb), and nickel (128 ppb) were detected above their CVs. Sediment: | An RI has been completed. A draft of the feasibility study is scheduled to be completed by March 2001. | Based on available data no public health hazard exists. Most contaminants do not exceed CVs in surface soil and access to the area is restricted. Drinking water for the base is processed using air strippers prior to its distribution. The two drinking water supply wells located in this area are tested monthly for VOCs and some metals. |
| Area 8 Solid Waste Landfill | Area 8 is located in the southwestern corner of the plant. The area was used from the mid-1960s until 1988 to dispose of sludge from the IWTP. The area consists of eight unlined pits which were used to dispose of oil and grease from the IWTP. In addition, the area contains nine other earth pits used to dispose sludge and other IWTP-related materials, and to dispose of construction debris created during construction of the "Big Ditch." | Subsurface Soil: No VOCs were detected above their CVs. Two metals, lead (721 ppm) and arsenic (16 ppm), were detected above their CVs. Groundwater: One explosive, RDX (0.91 ppb) was detected above its CV. Metals detected above their CVs include lead (77 ppb), arsenic (102 ppb), cadmium (14 ppb), chromium (288 ppb), and nickel (211 ppb). | An RI/FS has been conducted. Eight unlined oil and grease pits were removed in 1989 under an approved closure plan. The sludge disposal pits are currently covered. At the time of the RI/FS, Area 8 was included as a separate OU. However, Area 8 has since been dropped as an OU and it is now included with the Installation-Wide OU. | This area does not pose a public health hazard because none of the contaminants exceeded CVs in surface soil and access to the area is restricted. There are no supply wells located in Area 8. |
| Area 9 Building 60 (Mercurous Nitrate - Zinc Cyanide) Treatment Facility | Area 9 is located near the center of the plant, just south of Area 18. The facility was used to treat mercurous nitrate generated during testing of small arms and cartridges. Treatment of wastes is no longer taking place at this site. A sludge drying bed located next to the building was used from the late 1950s to early 1960s. | Groundwater: Cadmium (6.4 ppb) and nickel (122 ppb) were detected at levels above their CVs. | An RI/FS was conducted in 1990. | This area does not pose a public health hazard because of the low levels of contaminants detected and because access to the area is restricted. |
| Area 10 Firing Range Waste Dump | Area 10 is located in the east-central part of the plant and covers about 3 acres. It contains ammunition waste from ordnance used at the firing range, including armor piercing, incendiary, and depleted uranium. | Surface soil: No contaminants were detected above CVs. Groundwater: Radioactivity was detected in groundwater samples. Both alpha activity (62 pCi/L) and beta activity (211 pCi/L) were detected above Missouri groundwater stadards and national primary drinking water regulations. | An RI has been completed. The area has undergone cleanup activities for depleted uranium which is being overseen by the Nuclear Regulatory Commission. | This area poses no public health hazard because contaminants do not exceed CVs in surface soil. Access to the area is restricted and there are no drinking water supply wells located in this area. Alpha and beta radioactivity detected in groundwater does not pose a hazard since no completed past or current exposure pathway has been identified. |
| Area 12 NPL Lagoon and Paint Shop | Area 12 is located in the south-western portion of the plant just south of Buildings 6 and 10. From the late 1950s to the mid-1960s, two disposal lagoons, each covering approximately 10,000 ft2, were used to dispose of liquid wastes such as solvents and possibly small quantities of explosives from the chemical laboratory. | Groundwater: One VOC (TCE-200 ppb) was detected above its CV. Two SVOCs, N-nitrosodi-phenylamine (14 ppb) and B2EHP (26 ppb), were detected at levels above their CVs. One metal, chromium (3,800 ppb) was detected above its CV. Two drinking water supply wells are located in Area 12. TCE (52 ppb) was detected in raw water in one of the supply wells (17-AA). | A PA and SI have been completed. | No apparent public health hazard exists. Access to the area is restricted. On- site groundwater is processed through air strippers and treated prior to distribution. The drinking water supply is tested monthly for VOCs and some metals. |
| Area 13 Building 35 Drainage Area | Area 13 is located in the south-central section of the plant. Building 35 is the metal parts manufacturing facility, which until 1971 discharged sodium dichromate wastewater directly to the ground. | Surface soil: Three metals, antimony (9,000 ppm), total arsenic (9.3 ppm), and lead (48,000 ppm) were detected above their CVs. Groundwater: Surface water: | A PA and SI have been completed. LCAAP is currently conducting a RI/FS for this area. | This area does not pose a public health hazard because access to Area 13 is restricted and prolonged exposure to surface soil or surface water is very unlikely. There are no drinking water supply wells located in this area. |
| Area 14 Burning Ground and Sludge Disposal Area | Area 14 is located in the north-central part of the LCAAP manufacturing area. The area contains a burning ground, used by the plant fire department to burn wooden ammunition boxes from 1951 through 1967, an IWTP sludge disposal area covering about 30,000 ft2 which was closed in 1965, and four above ground fuel tanks located just north of the IWTP. Wastes include heavy metals and possibly explosives. | Groundwater: TCE was detected (45 ppb) in one sample above its CV. However, subsequent samples taken in the same location did not detect TCE. One SVOC, B2EHP (96 ppb) was detected in samples above its CV. One supply well (17-P) is located in this area. Vinyl chloride (5.3 ppb) was detected above its CV. | A PA and SI have been completed. No further action is planned. | This area does not pose a public health hazard. Access to the area is restricted. On-site groundwater is processed through air strippers and treated prior to use as drinking water. |
| Area 15 Temporary Surface Impoundment | Area 15 is in the south-central part of the plant and contains two SWMUs. One SWMU is a surface impoundment approximately 50 ft x 50 ft designed to temporarily hold wastes from Building 35. The impoundment was constructed during the 1970s and its use was discontinued prior to 1980. The other SWMU is a concrete lift station used to transfer wastes generated in Building 35. | Surface soil: Two metals, lead (2,200 ppm), and arsenic (34 ppm) were detected at levels above their CVs. Groundwater: | A PA and SI have been completed. An RI/FS is being conducted. | No public health hazard is likely to exist because access to the area is restricted. There are no supply wells located in this area. |
| Area 19 Sumps | Area 19, located just northwest of the center of the plant, was initially investigated as a sump area. A transformer pad is located southeast of Building 5. There may also be an underground storage tank used for holding laboratory waste, however, this has not been confirmed. | Subsurface soil: Very limited sampling showed low levels of Aroclor 1260 at concentrations of 0.63 and 2.11 ug/g, respectively in samples taken approximately 6 inches below the surface. These levels are below ATSDR's CVs. | A PA/SI has been completed. No further action is planned. | No public health hazard exists for this area because access is restricted and sampling data do not indicate that polychlorinated biphenals (PCBs) are present at harmful levels. |
| Area 20 Building 2 Area | Area 20 is located in the northwestern portion of the plant. This area comprises the grounds around and adjacent to Building 2. Some solvent spills were reported in this area. This area is not considered to be a significant source of contamination. | Surface soil: Sampling did not indicate significant contamination in this area and those contaminants that were detected were below their CVs. | A PA and SI have been completed. | No public health hazard exists because this area does not contain levels of contaminants that are considered harmful. |
| Area 21 Closed Sumps. Building 3A and 12A. | Area 21 is located just northwest of the center of the plant. The primary focus of the investigation was on the sump. One electrical substation was sampled for PCBs. This area also contains buildings 3A and 12A, which were used during the 1960s for the machining and assembly of depleted uranium-containing .50 caliber and 20mm ammunition. | Surface soil: Results of soil sampling for PCBs around the transformer were negative. No other sampling was conducted. | A PA and SI have been completed. Buildings 3A and 12A were decontaminated during 1985-1986. Inspection by Nuclear Regulatory Commission (NRC) officials indicated that additional cleanup activities were required for Building 3A. According to LCAAP, remediation of Building 3A will be completed by September 2001. The wing of building 3A that has been contaminated with depleted uranium will be torn down. | No public health hazard exists because this area does not contain levels of contaminants that are considered harmful. |
| Area 22 Demolition Waste Dump | Area 22 is located in the north-central part of the plant. The waste source is a demolition waste dump whose period of operation was believed to be during the 1940s and early 1950s. | Surface soil: Metals were detected at levels below their CVs. Beta radiation (15.7 pCi/g) was detected in soil. Groundwater: | A PA and SI have been completed. | This area does not pose a public health hazard. Access to this area is restricted and exposure to any radioactive sources would be of very short duration and not of public health concern. On-site groundwater is processed through air strippers and treated prior to use as drinking water. |
| Area 23 Sludge Burial Pits | Area 23 is located just to the west of the center of the plant. The area covers approximately 34, 000 ft2 and contains four IWTP sludge burial pits, located on the east side, which closed in 1967. | Surface soil: Very low levels of VOCs were detected. | A PA/SI has been completed. No significant concentrations of contaminants were detected and this area is not recommended for further action. | No public health hazard exists because this area does not contain levels of contaminants that are considered harmful. |
| Area 24 Sanitary Wastewater Treatment Plant | This area is where the former Sanitary Wastewater Treatment Plant was located. The plant is currently inactive and operated from 1941 until 1990. The Plant is no longer used because the industrial wastewater and sanitary wastewater streams were combined and transported to Little Blue Valley Sewer District. | No sampling has been conducted at this site. | No corrective activities are anticipated for this area. | This area does not pose a public health hazard because access to the area is restricted and the treatment plant was not used to process or treat industrial wastes. |
| Area 25 Demolition Debris Dump | This area is located in the southwest corner of the plant. Investigations of this area were not conducted since the area contains predominantly asbestos-related materials. | Surface soil: No investigations were conducted for this area. Contamination is predominantly asbestos related materials. | A PA and SI have been completed. The plant has an ongoing asbestos abatement program. | There is no apparent public health hazard. Access to this area is restricted, however, it is relatively close (about 0.5 mile) to the only housing area on the plant. This area should be closely monitored by plant security to ensure that children from on-site housing do not gain access. |
| Area 26 Roofing Tar Waste Dump | Area 26 is located near the southern perimeter of the plant. The waste dump is approximately 7,500 ft2 and contains roofing tar materials. | Surface soil: SVOCs (total polycyclic aromatic hydrocarbons [PAHs]) (2,540 ppm) were detected at levels above their CVs. Two metals, arsenic (32 ppm) and lead (560 ppm), were detected above their CVs. | A PA and SI have been completed. | No public health hazard is likely to exist because access to this area is restricted. |
| Areas 27A and 27B Firing Range | The firing range has been in operation since the early 1950s to test all types of ammunition produced at LCAAP for function and accuracy. Area 27A is located in the south-central portion of the plant. This area is associated with the firing range and contains various ordnance and radioactive elements. Area 27B is located in the eastern part of the plant. This area is associated with the firing range and contains various ordnance and radioactive elements.
| Radiological survey: Elevated radioactivity is present in the impact area in Area 27B. Groundwater: Surface Water: | A PA and SI have been completed. Investigations have been conducted by the NRC. Initial plans were to remove the materials contaminated with depleted uranium is scheduled for this area. Upon further review, the NRC has agreed to transfer regulatory oversight to the EPA CERCLA program and the removal of depleted uranium will be postponed. | No public health hazard is likely to exist because access to this area is restricted. Contaminants in groundwater were below CVs and do not pose a health hazard. Transferring the oversight to EPA and not conducting an immediate removal is considered an acceptable short-term alternative because the firing range is still being used and the depleted uranium does not pose a public health hazard. |
| Area 28 Former Pipeline Leak | Area 28 is associated with an ARCO pipeline leak that reportedly occurred in the 1950s. There were no indications of contamination and the area was not investigated further. | There are no sampling data available. | A PA and SI have been completed. Due to the age of the reported spill it is not expected that evidence of the leak will be present. There is no need to investigate this area further. | No public health hazard exists because no contamination is likely from this old spill. |
| Area 29 Construction Landfill | Area 29 is located at the extreme western end of the plant. The area contains two construction debris landfills. The northern one was used during construction of the plant and the southern landfill was used during construction of the Big Ditch drainage diversion project between 1984 and 1987. | Subsurface soil: One metal, arsenic (15 ppb), was detected above its CV. Groundwater: | A PA and SI have been completed. | No public health hazard exists because this area does not contain levels of contaminants that are considered harmful. |
| Area 30 Demolition Dump | Area 30 is located in the northwest part of the plant and was used by the plant's fire department from 1951 to 1967 to burn wooden ammunition boxes. Wastes may include lead and explosive residues. | Subsurface soil: Antimony (1,730 ppm), arsenic (11.2 ppm), copper (220,000 ppm), and lead (200,000 ppm) were detected above their CVs. Groundwater: | A PA and SI have been completed. | No public health hazard is likely to exist because access to this area is restricted. |
| Area 31 Firebreak Waste Dumps | Area 31 is located in the northeastern corner of the plant. Waste includes assorted household debris and empty drums/ ammunition boxes scattered around the area. The site was likely active in the 1940s through the 1960s. | Surface soil: PAHs were detected in nearly half the soil samples collected. In two samples, seven PAHs were detected at levels greater than 1,000 ppm, well above their CVs. Some metals such as arsenic (420 ppm), lead (53,000 ppm), and mercury (170 ppm) were also detected above their CVs. Groundwater: | A PA/SI has been completed. No additional sampling is anticipated. | Area 31 poses no public health hazard because access to this area is restricted. There are no drinking water supply wells located in this area. |
| Area 32 Abandoned Houses | This area is located east of the center of the plant and contained approximately 10 abandoned houses. Only five houses are still intact and only two houses had any visible signs of contamination. One basement contained a number of empty 55-gallon drums which were removed prior to 1990. | Surface soil: One metal, lead (1,393 ppm) was detected at levels above its CV. | A PA and SI have been completed. All drums were removed in 1990. The source has been removed from the basement of one of the abandoned dwellings and the other abandoned house showed only one metal detection that exceeded its CV. | No public health hazard exists because access is restricted and the source of contamination has been removed. |
| Area 33 Building 53 Area Sumps | This area is located in the north-central region of the plant. Sumps were used for wash-down water during operations at several buildings at the area. These buildings were used for blending and pelletizing operations for RDX. Explosives and lead have been found on this site. Drains in the area were cemented closed during the 1970s. | Surface soil: One explosive, (RDX =502 ppm), was detected at levels above its CV. One metal, Lead (1,892 ppm), was also detected at levels above its CV. | A Pa and SI have been completed. No additional sampling is planned. Most past sampling results indicate little contamination of the area. No additional evaluation or remediation of this area is anticipated. | No public health hazard exists because access to this area is restricted. |
| Northeast Corner Operable Unit | ||||
| Area 11 Burning Grounds | Area 11 is located in the northeast part of the plant near Areas 16 and 17. The Area 11 Burning Grounds were used for open burning of explosive compounds from 1957 through 1994, and were required to be closed under State of Missouri hazardous waste regulations. The area may still be used for limited safety and training procedures. | Soil: No contaminants were detected above their CVs. Groundwater: One explosive, RDX (96 ppb) was detected above its CV. | An RI/FS has been completed. An Interim Remedial Action record of decision (ROD) for the Northeast Corner OU was released in September 1998. Remedial plans include the installation of a subsurface permeable reactive wall (PRW) to treat contaminated groundwater and a monitoring program to evaluate the effectiveness of the PRW. The PRW is expected to be completed by September, 2000 (G. Anderson, personal communication, IRP Project Manager, LCAAP, June 26, 2000). A final closure plan was approved for Area 11 in October, 1994. | No public health hazard exists because access to this area is restricted. There are no drinking water supply wells located in this area. |
| Area 16 Abandoned Landfill/Waste Glass, Paints, Solvents Area | Area 16 is located in the northeast part of the plant. The area contains five SIMUS: 1) an open burning ground operated from 1952 through 1957; 2) several small trenches which received solvents during the 1950s; 3) an area where five above-ground waste oil and solvents tanks were operated from 1980 through 1982; 4) an abandoned solid waste landfill which accepted plant-generated industrial/construction waste from 1970 through 1979; and 5) a pistol range used from 1952 through 1963. | Soil: Lead (3,000 ppm) and arsenic (49 ppm) were the only contaminants detected above their CVs. Lead was present in surface soil and arsenic was present in subsurface soil. Groundwater: Surface Water: | A PA and SI have been completed. An FS is currently underway. Final ROD for Interim Remedial Action for this operable unit (OU) has been completed. A plan is in place to regrade the landfill cover to reduce infiltration and surface water runoff. The plan also includes phased planting of trees on the landfill cap to reduce VOCs in leachate and groundwater. A groundwater extraction well was installed as part of the LCAAP Groundwater Containment Program. | No public health hazard is likely to exist because access to the area is restricted. On-site groundwater is processed through air strippers and treated prior to use as drinking water. Monitoring of the groundwater plume will be necessary to ensure that contaminants do not migrate off site. |
| Area 17 Current Sanitary Landfill/Oil and Solvents Pits. The Waste, Glass, Paint, and Solvents Area. | Area 17 is located in the northeastern part of the plant, immediately east of Area 16. The area contains five SIMUS: 1) a currently permitted sanitary landfill; 2) three oil and solvent pits which received IWTP oil and grease, waste solvents, and waste oil from 1960 through 1980; 3) an area where wastes were disposed of in shallow pits and a stream bed from 1960 through 1970; 4) an open burning pad which operated for a short period during 1975; and 5) a pistol range, which is currently used by the LCAAP security force. | Oil and solvents pits - Soil borings: Groundwater: Waste, glass, paint, and solvents area - Soil: Surface Water: | A PA and SI have been completed. Final ROD for interim remedial Action for this OU has been completed. Soil cover over Area 17 solvent pits will reduce exposure to VOCs from contaminated soil and minimize further migration of VOCs to the groundwater by controlling runoff of precipitation. The placement of the soil cover will be completed at the same time the PRW is installed (G. Anderson, IRP Project Manager, LCAAP, personal communication, June 26, 2000). | No public health hazard is likely to exist because access to the area is restricted. On-site groundwater is processed through air strippers and treated prior to use as drinking water. The soil cover over the solvent pits is expected to reduce runoff and prevent contaminants from migrating off site. Monitoring of the groundwater plume will be necessary to ensure that contaminants do not migrate off site. |
| Area 18 Operable Unit | ||||
| Area 18 Burn Pits/ Lagoons/ Trenches Area | Area 18 is located in the north central part of the plant. The pits were used to burn plant construction debris and solvents. The pits were operated from 1952 through 1975. | Surface Soil: Two VOCs, TCE (60 ppm) and tetrachloroethylene (11 ppm), were detected above their CVs. Groundwater: Groundwater extraction well (17-FF) contained two VOCs, 1,2-DCE (250 ppb) and vinyl chloride (150 ppb), which exceeded their CVs. | Final ROD for this operable unit has been released. | No apparent public health hazard exists because access to this area is restricted. One former supply well (17-FF) located on the western portion of Area 18 has been converted to a groundwater extraction well. |
1. Maximum concentration detected is presented
| Pathway Name | Source of Contamination | Environmental Medium | Point of Exposure | Route of Exposure | Potentially Exposed Population | Comments |
|---|---|---|---|---|---|---|
| LCAAP drinking water supply wells | Thirteen active production wells that draw water from the contaminated HU 2 water bearing zone at LCAAP. | Groundwater | Supply wells and connecting water distribution system across the plant. | Ingestion, dermal contact, and inhalation | Workers and visitors at LCAAP | Past: Supply wells at LCAAP have contained VOCs slightly above CVs. These VOCs, however, were not found at levels that would cause adverse health effects. ATSDR concludes that exposure to past drinking water supplies at LCAAP posed no apparent public health hazard. Current and Future: |
| Off-site private drinking water wells | Area 18 OU and the Northeast Corner OU contaminated groundwater plumes are a potential source of contamination for private wells located north of the plant. | Groundwater | Off-site private drinking water wells | Ingestion, dermal contact, and inhalation | Residents living to the north of the Area 18 OU and North East Corner OU. | Past, current and future: Quarterly monitoring of some private wells to the north of the Area 18 OU and the Northeast Corner OU was conducted between 1987 and 1993. Private wells to the north of the Area 18 OU and the Northeast Corner OU do not contain levels of VOCs or metals at levels that would pose an apparent public health hazard. |
| Soil | Waste disposal activities at LCAAP | Surface soil | Areas of contamination at LCAAP | Incidental ingestion and/or dermal contact | On-site residents, visitors, and adult workers | Past: The entire base is fenced and access is restricted. On-site residents would not likely be exposed to contaminated soil because the housing area is located away from the main plant and most of the contamination sources are located in the industrial area of the plant where access is restricted. Any exposures would be infrequent and of short duration. Past exposures to soil most likely posed no public health hazard. Current and Future: |
| Surface water and sediment | Waste disposal activities at LCAAP | Surface water and sediment | Areas of contamination at LCAAP | Incidental ingestion and/or dermal contact | On-site residents, visitors, and adult workers | Past: The entire base is fenced and access is restricted. On-site residents would not likely be exposed to contaminated surface water or sediment because the housing area is located away from the main plant and most of the contamination sources are located in the industrial area of the plant where access is restricted. The only surface water body routinely used for recreation is Veteran's Lake. This water body is not in close proximity to contaminated source areas. Current and Future: |
| Air | Open burning of explosives on site, sealing operations units, and the Explosive Waste Incinerator (EWI). | Ambient Air | Ambient Air | Inhalation and/or ingestion | On-site and off-site residents, visitors, and workers at LCAAP. | Past: Open burning of explosives was permitted in the past at LCAAP. In addition, VOC emissions may have occurred at the sealing operations units. Although ambient air monitoring was not conducted at LCAAP in the past, it is unlikely that ambient air concentrations would have been high enough to pose a health hazard. For this reason, past air exposures pose no apparent public health hazard. Current and future: |

Figure 2. LCAAP Operable Unit (OU) and Source Area Map

Figure 3. ATSDR's Exposure Evaluation Process



