ATSDR - PHA - Air Force Plant PJKS, Waterton, Jefferson County, Colorado

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ATSDR > Public Health Assessments & Consultations

PUBLIC HEALTH ASSESSMENT

AIR FORCE PLANT PJKS
WATERTON, JEFFERSON COUNTY, COLORADO

TABLES

Table 1. Evaluation of Potential Public Health Hazards Associated with the Installation Restoration Program Sites and Areas of Concern

Site Site Description/Waste Disposal History Investigation Results/ Environmental Monitoring Results Current Status Evaluation of Public Health Hazard

OU1

Systems and Components General Area Area subject to spills of hazardous materials. Subsurface Soil: No VOCs were detected above CVs. Industrial area.
Evaluated in the RI/FS. No public health hazard exists from direct contact with subsurface soil because the area is inaccessible to the public. Furthermore, VOCs were detected at levels that do not pose a health hazard.

Oxidizer Waste Rinse Water Tank (BC-61) Receives water from a French drain beneath N₂O₄ tank vault. Subsurface Soil: No VOCs or SVOCs were detected. Industrial area. Evaluated in the RI/FS. No public health hazard exists because VOCs or SVOCs were not detected in subsurface soil. Furthermore, the area is inaccessible to the public.

Systems Fuel Tank Drain Drainage system located beneath a 20,000-gallon hydrazine fuel tank and vault. Subsurface Soil: No VOCs or SVOCs were detected. Industrial area. Evaluated in the RI/FS. No public health hazard exists. No VOCs or SVOCs were detected in subsurface soil. Furthermore, the area is inaccessible to the public.

Leak Detection Line Drain A perforated PVC pipe used to detect leaks from overhead drain line transmitting N₂0₄rinse water. Subsurface Soil: No VOCs or SVOCs were detected.
Soil Gas: TCE and Freon -113 were detected.
Industrial area. Evaluated in the RI/FS. No public health hazard exists. The area is inaccessible to the public so direct contact with soil or inhalation of soil gas is unlikely to occur.

Components Cavitette Concrete tank and aerator that collects sewage and wastewater from the Components Facility; effluent containing solvents is directed to a leach field. Subsurface Soil: No VOCs were detected above CVs. The area has been administratively closed and will be addressed in the compliance program. No public health hazard exists from direct contact with subsurface soil because the area is inaccessible to the public. Furthermore, contaminants were detected at levels that do not pose a health hazard.

Systems Cavitette Underground tank and aerator that collects sewage and wastewater from systems facility; effluent containing solvents is directed to leach field. Subsurface Soil: No VOCs were detected. The area has been administratively closed and will be addressed in the compliance program. No public health hazard exists from direct contact with subsurface soil. The area is inaccessible to the public and no contaminants were detected in subsurface soil.

OU2

Engineering Propulsion Laboratory An area subject to spills of hazardous materials. Subsurface Soil: No VOCs, metals, or SVOCs above CVs.
Groundwater: VOCs were detected above CVs. No SVOCs were detected.

Industrial area. Evaluated in the RI/FS. No public health hazard exists. The area is inaccessible to the public and the groundwater beneath the site is not used for drinking water. Furthermore, VOCs and SVOCs were detected in subsurface soil at levels that do not pose health hazards.

Upper Volcano Above grade conical unlined pit used to collect and dispose of waste solutions from Cold Flow Laboratory, including solvents, kerosene, liquid nitrogen, N₂O₄, and hydrazine wastewater. Surface and Subsurface Soil: No VOCs were detected in the soil. Industrial area. Evaluated in the RI/FS. No public health hazard exists from direct contact with soil. The area is inaccessible to the public and no contaminants were detected in soil.

Lower Volcano Above grade conical unlined pit used to collect and dispose of waste solutions from Cold Flow Laboratory, including solvents, kerosene, liquid nitrogen, hydrazine wastewater, and N₂O₄. Surface and Subsurface Soil: No VOCs were detected. Industrial area. Evaluated in the RI/FS. ATSDR will review monitoring data from the RI/FS. It is unlikely that a public health hazard exists because the area is inaccessible to the public.

Valve Shop Acid Tank (T5-A) Aboveground tank and associated buried pipeline known to have leaked hydrofluoric and nitric acids to surrounding soil. Subsurface Soil: No VOCs, fluoride, or PAHs were detected above CVs.
Soil Gas: VOCs, primarily TCE and Freon-113, were detected.

Groundwater: TCE detected at levels above the CV. No SVOCs were detected.
Industrial area. Evaluated in the RI/FS. No public health hazard exists because the area is inaccessible to the public and the groundwater beneath the site is not used for drinking water. Furthermore, contaminants in subsurface soil were detected at levels that do not pose a health hazard.

Valve Shop Solvent Storage Area Two areas used for storing spent solvents, including TCE and 1,1,1-TCA, and possibly Freon. Subsurface Soil: No VOCs were detected above CVs.
Soil Gas: TCE, 1,1,1-TCA, and Freon-113 were detected.

Groundwater: VOCs were detected above CVs. No SVOCs were detected.
Industrial area. Evaluated in the RI/FS. No public health hazard exists because the area is inaccessible to the public and the groundwater beneath the site is not used for drinking water. Furthermore, the VOCs in soil were detected at levels that do not pose a health hazard.

Riprap Area West of Central Support Building T-17 A disposal site for broken asphalt and concrete. Subsurface Soil: Metals were detected at levels above background, but below the CVs. Industrial area. Evaluated in the RI/FS. No public health hazard exists from direct contact with soil. The surface and subsurface soils are inaccessible to the public. Furthermore, the contaminants in soil were detected at levels that do not pose a health hazard.

Valve Shop Process Water Drain A drain used to discharge domestic waste. Subsurface Soil: No VOCs were detected above CVs.
Soil Gas: TCE and Freon-113 were present in soil gas.
Industrial area. Evaluated in the RI/FS. No public health hazard exists from direct contact with soil or soil gas. The area is inaccessible to the public. Furthermore, contaminants were detected at levels that do not pose a health hazard.

Decontamination Trailer Tank Spill Located immediately north of the Central Support Building, the tank contained Freon- 113 and alcohol. In addition, diesel fuel may have spilled from a broken feeder line. The tank has been removed. Subsurface Soil: No VOCs or SVOCs were detected above CVs.
Soil Gas: VOCs, primarily TCE and Freon-113, were detected.

Groundwater: TCE was detected at levels above the CV; other VOCs and SVOCs were detected at levels below CVs.
Industrial area.
The area has been closed pursuant RCRA requirements. Evaluated in the RI/FS. No public health hazard. The area is inaccessible to the public and the groundwater beneath the site is not used for drinking water. Furthermore, VOCs and SVOCs in soil were detected at levels that do not pose a health hazard.

Blockhouse Cavitette A 3,000-gallon buried metal tank and aerator with leach field, which was used as a septic system. Subsurface Soil: No VOCs were detected. Because of its active status, this area was administratively closed and is addressed under the compliance program. No public health hazard exists from direct contact with soil. No contaminants were detected and the area is inaccessible to the public.

Field and Central Support Septic System A 5,000-gallon buried concrete tank and aerator with leach field, which was used as a septic system. No data specific to the area were available for review. Because of its active status, this area was administratively closed and is addressed under the compliance program. Most likely no public health hazard exists because the area is inaccessible to the public.

UST Tank 3 stored fuel oil in Building T-17. Area to be evaluated during RI/FS. No data specific to the area were available for review. Most likely no public health hazard exits because the area is inaccessible to the public.

OU3

D-1 Test Stand Area where rocket engine assemblies were tested. Used hydrazine and No. 6 diesel. Surface and Subsurface Soil: TCE was detected below the CV; no other VOCs were detected. Industrial area. Evaluated in the RI/FS. No public health hazard exits. The area is inaccessible to the public. VOCs were either not detected or detected at levels that do not pose a health hazard.

D-2 Test Stand Area where rocket engine assemblies were tested. Used hydrazine No. 6 diesel, kerosene, N₂O₄, and solvents. Includes AOC 3, 4, and 5. Surface and Subsurface Soil: TCE was detected below the CV; no other VOCs were detected. Industrial area. Evaluated in the RI/FS. No public health hazard exists. The area is inaccessible to the public and VOCs were either not detected or detected at levels that do not pose a health hazard.

D-3 Test Stand Area where rocket engine assemblies were tested. Used kerosene and solvents. Surface and Subsurface Soil: No VOCs were detected. Industrial area. Evaluated in the RI/FS. No public health hazard exists. The area is inaccessible to the public and no VOCs were detected in the soil.

D-4 Test Stand Area where rocket engine assemblies were tested. Used kerosene and solvents. Surface and Subsurface Soil: No VOCs were detected. Industrial area. Evaluated in the RI/FS. No public health hazard exists. The area is inaccessible to the public. No VOCs were detected in soil.

T-8A Containment Pond The pond is the terminus of a network of ditches, flumes, and drainage pipes for the AFP PJKS facility. Process water possibly contained hydrazine, hydrocarbons, N₂O₄, and solvents. Sediment: Metals were detected above background levels but below CVs. No VOCs or SVOCs were detected. Industrial area. Evaluated in the RI/FS. No public health hazard exists from direct contact with sediment. The area is inaccessible to the public. Furthermore, VOCs, SVOCs, and metals in sediment were either not detected or detected at levels that do not pose a health hazard.

D-3 Fuel Holding Pond A small concrete-lined pit located in the southeast of the D-3 Test stand; used to collected residual kerosene-type (RP-1) rocket fuels. Subsurface Soil: Metals were detected above background levels but below CVs. Low levels of dichloromethane were detected; no other VOCs and SVOCs were detected. Industrial area. Evaluated in the RI/FS. No public health hazard exists from direct contact with soil because the area is inaccessible to the public. Furthermore, metals, SVOCs, and VOCs in subsurface soil were either not detected or detected at levels that do not pose a health hazard.

D-1 Landfill The landfill contained nonhazardous and possibly hazardous refuse generated from AFP PJKS and Lockheed Martin Astronautics activities. Subsurface Soil: PCBs, VOCs, and metals were detected at levels below CVs. Various PAHs were present in levels greater than the CV for benzo(a)pyrene.
Soil Gas: TCE was detected.

Groundwater: VOCs detected in the alluvium and bedrock above CVs.
Industrial area. Evaluated in the RI/FS. No public health hazard exists. The area is inaccessible to the public and groundwater beneath the site is not used for drinking water.

T-8 Drainage Flumes Process waters possibly containing hydrazine, kerosene, N₂O₄, or solvents. Surface and Subsurface Soil: No VOCs were detected. Industrial area. Evaluated in the RI/FS. No public health hazard exists. The area is inaccessible to the public and VOCs were not detected in soil.

Riprap Area North of Pond T-8A Potential waste burial area in a former gulch intersecting the East Fork of Brush Creek. Possibly contains construction fill, which may be a contaminant source. Subsurface Soil: Metals (copper, nickel, lead, and sodium) were detected above background levels but below CVs. No VOCs were detected.
Soil Gas: Low levels of VOCs, including TCE, Freon-113, 1,1-DCE, and cis-1,2-DCE were detected.

Groundwater: VOCs detected above CVs. No SVOCs were detected.
Industrial area. Evaluated in the RI/FS. No public health hazard exists. The area is inaccessible to the public and the groundwater beneath the site is not used for drinking water. Furthermore, contaminants in soil were either not detected or detected at levels that do not pose a health hazard.

D-1 Septic Tank and Leaching Field A septic system that possibly contained solvents. Surface and Subsurface Soil: No VOCs were detected. Industrial area. Evaluated in the RI/FS. No public health hazard exists. The area is inaccessible to the public and VOCs were not detected in the soil.

D-1 Fuel Storage Area A storage area that contained hydrazine, kerosene, and N₂O₄. Surface Soil: No VOCs were detected.
Subsurface Soil: VOCs were infrequently detected, but below CVs.
Industrial area. Evaluated in the RI/FS. No public health hazard exists. The area is inaccessible to the public and VOCs were not detected in surface soil.

D-2 Fuel Storage Area A storage area that contained hydrazine, kerosene, and N₂O₄. Surface and Subsurface Soil: No VOCs were detected.

Industrial area. Evaluated in the RI/FS. No public health hazard exists. The area is inaccessible to the public and VOCs were not detected in soil.

D-3 Fuel Storage Area A storage area that contained kerosene. Surface and Subsurface Soil: No VOCs were detected. Industrial area. Evaluated in the RI/FS. No public health hazard exists. The area is inaccessible to the public and VOCs were not detected in soil.

D-4 Fuel Storage Area A storage area that contained kerosene. No data specific to the area were available for review. Industrial area. Evaluated in the RI/FS. Most likely no public health hazard exists because the area is inaccessible to the public.

D-4 Fuel Holding Pond A small concrete-lined pit used to collect kerosene (RP-1). Surface and Subsurface Soil: No VOCs were detected. Industrial area. Evaluated in the RI/FS. No public health hazard exists. The area is inaccessible to the public and no VOCs were detected.

Acid Neutralization Pit Area contained nitric, hydrofluoric acid, and possibly 1,1,1-TCA. Surface and Subsurface Soil: No VOCs were detected. Industrial area. Evaluated in the RI/FS. No public health hazard exists. The area is inaccessible to the public and no VOCs were detected.

T-31 Storage Tank A 1 million gallon underground tank for process waters (possibly containing hydrazine , kerosene, N₂O₄, solvents) and fuel oil. Subsurface Soil: No PCBs, VOCs, or metals were detected. Industrial area. No further action required. No public health hazard exists from direct contact with soil. The area is inaccessible to the public. Furthermore, contaminants were not detected in subsurface soil collected from this area.

OU4

Lariat Gulch Groundwater Plume Area of contaminated groundwater beneath Lariat Gulch tributary basin. Groundwater: VOCS, primarily TCE, were detected above CVs. Evaluated in the RI/FS. No public health hazard associated with on-site contamination because the groundwater beneath the site is not used for drinking water. This plume has migrated off site, but it has not affected private well or municipal water supplies.

OU5

West Fork of Brush Creek Groundwater Plume Area of contaminated groundwater beneath a portion of West Fork of Brush Creek Basin, including a tributary from the D-1 Test Stand. Includes AOC 2. Groundwater: One benzene plume (4.4 - 38 ppb) is located in the alluvial groundwater and one TCE plume (160 ppb) is defined in the bedrock.

Evaluated in the RI/FS. No public health hazard associated with on-site contamination because the groundwater beneath the site is not used for drinking water.

East Fork of Brush Creek Groundwater Plume Area of contaminated groundwater beneath a portion of East Fork of Brush Creek Basin. Groundwater: Two TCE plumes (100 - 3,900 ppb), two 1,1,1-TCA plumes (0.8 -870 ppb), and one nitrate plume (10,000 - 72,000 ppb) are located along the alluvial groundwater. One TCE plume (100 - 900 ppb) and one nitrate plume (12,000 - 39,000 ppb) are defined in the bedrock. Evaluated in the RI/FS. No public health hazard associated with on-site contamination because the groundwater beneath the site is not used for drinking water. This plume has migrated off site to the Lockheed Martin Astronautics property, and possibly to the Kassler area and the Kassler Water Treatment Plant. TCE and 1,1,1-TCA were detected at levels above the MCLs, however, they do not pose a health hazard.

OU6

OTL Oil Leak Site of former UST that leaked 600 to 1,000 gallons of fuel oil. Subsurface Soil: VOCs and PAHs were detected at levels below the CVs.
Soil Gas: TCE contamination is widespread, but much lower levels of other VOCs were detected.
Industrial area. Evaluated in the RI/FS. No public health hazard exists because the area is inaccessible to the public.

OTL Cavitette Septic system for OTL. Subsurface Soil: TCE and PCE were detected below CVs; no other VOCs were detected. Because of its active status, this area was administratively closed and is addressed under the compliance program. No public health hazard exists. VOCs were detected at levels that do not pose health hazards.

PCB Transformer Station #2 The location of a former transformer containing PCBs. No leaks have been reported. Subsurface Soil: No PCBs were detected. Industrial area. Evaluated in the RI/FS. No public health hazard exists from direct contact with soil. The area is inaccessible to the public and no PCBs were detected in subsurface soil.

OTL Open Detonation/ Open Burning pit Area contained 2,4,6-trinitrotoluene and hexahydro-1,3,5-Trinitron-1,3,5-triazine. Surface Soil: No VOCs were detected. RCRA-designated site. No public health hazard exists. VOCs were detected at levels that do not pose a health hazard.

USTs

UST Tank MM7 in Building T-23 contained heating oil between 1956 and 1990. The tank and associated contaminated soil have been removed. No further action required. No public health hazard exists.

UST Tank 005 in Building T-A contained heating oil between 1956 and 1988. The tank and associated contaminated soil have been removed. No further action required. No public health hazard exists.

UST Tank MM4 in Building T-6. The tank and associated contaminated soil have been removed. No further action required. No public health hazard exists.

UST Tank MM8 in Building T-B contained heating oil between 1956 and 1988. The tank and associated contaminated soil have been removed. No further action required. No public health hazard exists.

UST Tank MM 11 in Building T-2A contained heating oil between 1956 and 1988. The tank and associated contaminated soil have been removed. No further action required. No public health hazard exists.

UST Tank MM 12 in Building T-2B contained heating oil between 1956 and 1988. The tank and associated contaminated soil have been removed. No further action required. No public health hazard exists.

UST Tank MM at Test Stand D-3 contained heating oil between 1956 and 1988. The tank and associated contaminated soil have been removed. No further action required. No public health hazard exists.

UST Tank MM at Test Stand D-4 contained heating oil between 1956 and 1988. The tank and associated contaminated soil have been removed. No further action required. No public health hazard exists.

UST Tank MM in Building T-17A contained degreasing wastewater between 1956 and 1988. The tank and associated contaminated soil have been removed. No further action required. No public health hazard exists.

UST Tank MM 6 in Building T-A contained heating oil between 1956 and 1988. The tank and associated contaminated soil have been removed. No further action required. No public health hazard exists.

UST Tank MM 9 in Building T-22 contained heating oil between 1956 and 1988. The tank and associated contaminated soil have been removed. No further action required. No public health hazard exists.

UST T-1A (B) Oil Leak associated with No. 2 diesel fuel used between 1956 and 1986. The tank and associated contaminated soil have been removed. No further action required. No public health hazard exists.

Miscellaneous Sites

PCB Transformer Station PCB Transformer Station used between 1956 and 1986. No data specific to the area was available for this review. No further action required. Managed under Toxic Substances Control Act. Mostly likely no public health hazard exists, because the area is inaccessible to the public.

T-28H Floor Drain The drain servicing the Boiler Chiller Plant; water flows continually and may contain oil, grease, and solvents. Subsurface Soil: No VOCs were detected above CVs. PAHs were detected at levels above the CV for benzo(a)pyrene. No further action required. No public health hazard exists from direct contact with soil. The area is inaccessible to the public.

T-28D Equipment Room Floor Drain A drain servicing a room with a compressor, a water heater, and an air conditioning heat exchanger. Subsurface Soil: No VOCs, including Freon-113, or SVOCs were detected. No further action required. No public health hazard exists from direct contact with subsurface soil. The area is inaccessible and VOCs and SVOCS were not detected in subsurface soil.

Central Support Storage Area Area used as a temporary storage for waste solvents, oil, and methanol. Subsurface Soil: No VOCs or PAHs were detected above CVs.
Soil Gas: Only low levels of TCE were detected.

Groundwater: TCE was detected at levels above the CV; no other VOCs or SVOCs were detected above CVs.
No further action required. No public health hazard exists. The area is inaccessible to the public and groundwater beneath the site is not used for drinking water. Furthermore, no contaminants were detected in subsurface soil.

Missile Storage Building Drain The drain collected water, grease, oil, and solvents from the roof and floor of the Missile Storage Building. Subsurface Soil: No VOCs, metals, or SVOCs were detected above CVs.
Groundwater: Naphthalene was detected above the CVs for benzo(a)pyrene; no other SVOCs or VOCs were detected above CVs.
No further action required. No public health hazard exists because the area and subsurface soils are inaccessible to the public and groundwater beneath the site is not used for drinking water. Furthermore, contaminants were detected in soil at levels that do not pose a health hazard.

Pumping Station #2 Drain Located along the north side of the East Fork of Brush Creek, the drained service process waters contained possible grease and solvents. Subsurface Soil: No VOCs were detected. PAHs were detected above the CV for benzo(a)pyrene. Industrial area. No further action required. No public health hazard exists from direct contact with soil. The area is inaccessible to the public.

AOCs

T-13A Deluge Tank The tanks contained process water, including hydrazine, jet fuels, and solvents. Subsurface Soil: No VOCS were detected. Industrial Area. Evaluated in the RI/FS. No public health hazard exists. The area is inaccessible to the public and no VOCs were detected.

T-31 Chemical Treatment Facility The facility used treatment chemicals, including oxidizers and copper sulfate. Includes AOC 6. Surface and Subsurface Soil: No VOCs were detected. Industrial area. Evaluated in the RI/FS. No public health hazard exists. The area is inaccessible to the public and no VOCs were detected.

Key:

AOC = Areas of Concern
ppb = parts per billion
CERCLA = Comprehensive Environmental Response, Compensation, and Liability Act
CVs = comparison values
1,1-DUE = 1,1- dichloroethylene
cis-1,2-DUE = cis-1,2-dichloroethylene
ECL = Engineering Propulsion Laboratory
IRP = Installation Restoration Program
N₂O₄ = nitrogen tetroxide
OTL = Ordnance Testing Laboratory
OU = operable unit
PAHs = polycyclic aromatic hydrocarbons
PCBs = polychlorinated biphenyls
PVC = polyvinyl chloride
RCRA = Resource Conservation and Recovery Act
RI/FS = supplemental remedial investigation/feasibility study
SVOCs = semi-volatile organic compounds
1,1,1-TCA = 1,1,1-trichloroethane
TCE = trichloroethylene
UST = underground storage tank
VOCs = volatile organic compounds

Note: Soil samples were collected from greater than 1 feet below ground surface. For the purposes of this report, these sample are considered subsurface soil samples.
Sources: Engineering Science, 1988; U.S. Air Force, 1997.

Table 2. Exposure Pathways Evaluation Table

Pathway
Name Source of Contamination Environmental Medium Point of Exposure Route of Exposure Potentially Exposed Population Comments

Potential Exposure Pathways

Municipal Drinking Water from the Kassler Water Treatment Plant TCE, 1,1,1-TCA, & hexavalent chromium-- Source(s) upgradient to the Kassler Water Treatment Plant Groundwater Denver municipal water Ingestion, dermal contact, and inhalation Denver municipal water users Past:
TCE, 1,1,1-TCA, & hexavalent chromium were detected in the Kassler Water Treatment Plant infiltration galleries before the facility closed in 1985. TCE and 1,1,1-TCA were detected below the MCL and do not pose a health hazard.
Present and Future:
No exposure to AFP PJKS contaminants is occurring or expected to occur. The Kassler Water Treatment Plant has been closed since 1985 and no other Denver municipal water wells draw from the groundwater beneath or near AFP PJKS.

Private Drinking Water Wells TCE--Most likely related to upgradient source, including AFP PJKS Groundwater No exposure. Potentially private wells located at residences Ingestion, dermal contact, and inhalation Private residents Past, Present, Future:
Two plumes have migrated from AFP PJKS to the Lockheed Martin Astronautics site. No private drinking wells are located in the affected area.
TCE possibly related to AFP PJKS was detected in the Kassler area. No public health hazard exists for two upgradient and upstream domestic-use wells because conditions are not favorable for contaminant migration; even if contamination were to occur, the exposure should not result in adverse health effects.

Surface Water Contaminants related to upgradient sources, including AFP PJKS Surface Water No exposure. Potentially South Platte River and the Chatfield Reservoir Dermal contact while swimming, wading, boating, or fishing along the South Platte River or Chatfield Reservoir

Recreational users of the South Platte River and Chatfield Reservoir Past, Present, Future:
No TCE or other VOCs have been detected in the South Platte River samples. Therefore, swimming and other recreational uses of the South Platte River and the Chatfield Reservoir, into which it flows, are unlikely to result in adverse health effects.

Table 3. Summary of Contaminants in On-Site Groundwater Monitoring Wells

Contaminant Maximum Concentration (ppb) Comparison Value

Alluvium Bedrock Concentration (ppb) Reference

Benzene 38 34 1
5 CREG
MCL

1,2-Dichloroethane
(1,2-DCA) 18 ND 0.4
5 CREG
MCL

trans-1,2-Dichloroethylene (trans-1,2-DCE) 1,300 110 200
100 RMEG
MCL

1,1-Dichloroethylene
(1,1-DCE) 24 ND 0.06
7 CREG
MCL

Tetrachloroethylene (PCE) 7.7 5.6 0.7
5 CREG
MCL

1,1,1-Trichloroethane
(1,1,1-TCA) 870 3 200 MCL

Trichloroethylene (TCE) 11,000 8,900 3
5 CREG
MCL

Vinyl Chloride 430 ND 0.7
2 EMEG
MCL

Nitrate 72,000 39,000 10,000 MCL

N-nitrosodimethylamine (NDMA) 5 42 0.0007 CREG

ppb: parts per billion
CREG: Cancer Risk Evaluation Guide (1 x 10^-6 excess cancer risk)
EMEG: Environmental Media Evaluation Guide
RMEG: Reference Dose Evaluation Guide
MCL: EPA's Maximum Contaminant Level
ND: Not detected

Sources: Engineering Science, 1988, 1989; Parsons Engineering, 1996

Table 4. Summary of Contaminants in Groundwater (Alluvial) Near the Kassler Water Treatment Plant

Contaminant ^a Concentration
Range (ppb) Frequency of Detections Comparison Value

Concentration (ppb) Reference

1,1,1-Trichloroethane (1,1,1-TCA) 6.2 - 6.7 2/94 200 MCL

Trichloroethylene (TCE) 5 - 36 21/101 3
5 CREG
MCL

ppb: parts per billion
CREG: Cancer Risk Evaluation Guide (1 x 10^-6 excess cancer risk)
MCL: Maximum Contaminant Level
NA: Not available

Source: Clement Associates, 1990

Table 5. Summary of Contaminants in Kassler Water Treatment Plant (Before Closure)

Contaminant ^a Concentration
Range (ppb) Comparison Value

Concentration (ppb) Reference

1,1,1-Trichloroethane (1,1,1-TCA) 0.2 - 0.54 200 MCL

Trichloroethylene (TCE) 0.5 - 3.1 3
5 CREG
MCL

^a Includes contaminants detected before closure of the facility in 1985. Trans-1,2-dichloropropane, toluene, chlorobenzene, methylene chloride, ethylbenzene, and chloroform were detected but not at levels of quantification.

ppb: parts per billion
CREG: Cancer Risk Evaluation Guide (1 x 10^-6 excess cancer risk)
MCL: Maximum Contaminant Level

Sources: CDPHE, 1992; Denver Water, 1993

Table 6. Summary of Contaminants in On-Site Surface Water

Contaminant Maximum Concentration (ppb) Comparison Value

East Fork of Brush Creek Frequency of Detection Concentration (ppb) Reference

1,1,1-Trichloroethane (1,1,1-TCA) 0.7 - 6.1 6/27 200 MCL

Trichloroethylene (TCE) 1.1 - 20 9/27 3
5 CREG
MCL

Lead 1 - 60 4/33 15 EPA Action Level

ppb: parts per billion
CREG: Cancer Risk Evaluation Guide (1 x 10^-6 excess cancer risk)
MCL: Maximum Contaminant Level

Source: Engineering Science, 1988

Table 7. Summary of Contaminants in Off-Site Surface Water

Contaminant Concentration (ppb) Comparison Value

Kassler Area^a

South Platte River^b
Concentration
(ppb) Reference

Range^c Frequency of Detection^d Range Frequency of Detection

1,1,1-Trichloroethane (1,1,1-TCA) 6.3 - 8 3/41 ND 0/10 200 MCL

Trichloroethylene (TCE) 5 - 22 9/54 ND 0/10 3
5 CREG
MCL

^aIncludes data from 1985 through 1989 for samples collected in the Kassler Area. The maximum TCE concentration was detected in a seep in the Kassler Area.
^bIncludes data from 1991 through 1992 for samples collected from the bank of the South Platte River inside the Waterton Recreational Area, beside the infiltration galleries, and across the road from the former Kassler Water Treatment Plant.
^c The maximum and the minimum values shown may be the geometric mean of the sample set.
^d The value reported may not reflect the true frequency. Information on the number of samples taken was not provided for some locations where a chemical was not detected. The actual frequency is most likely lower than the value reported.

ppb: parts per billion
CREG: Cancer Risk Evaluation Guide (1 x 10^-6 excess cancer risk)
MCL: Maximum Contaminant Level
ND: Not detected

Sources: Clement Associates, 1990; Geraghty & Miller, Inc. 1990; Geraghty & Miller, Inc. 1998

FIGURES

Figure 1. Area Location

Figure 2. Site Location

Figure 3. Location of the Kassler Area and the Kassler Water Treatment Plant

Figure 4. ATSDR's Exposure Evaluation Process

Figure 5. AFP PJKS Contaminant Plumes

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Agency for Toxic Substances and Disease Registry, 1825 Century Blvd, Atlanta, GA 30345
Contact CDC: 800-232-4636 / TTY: 888-232-6348

Department of Health and Human Services

Pathway Name	Source of Contamination	Environmental Medium	Point of Exposure	Route of Exposure	Potentially Exposed Population	Comments
Potential Exposure Pathways
Municipal Drinking Water from the Kassler Water Treatment Plant	TCE, 1,1,1-TCA, & hexavalent chromium-- Source(s) upgradient to the Kassler Water Treatment Plant	Groundwater	Denver municipal water	Ingestion, dermal contact, and inhalation	Denver municipal water users	Past: TCE, 1,1,1-TCA, & hexavalent chromium were detected in the Kassler Water Treatment Plant infiltration galleries before the facility closed in 1985. TCE and 1,1,1-TCA were detected below the MCL and do not pose a health hazard. Present and Future: No exposure to AFP PJKS contaminants is occurring or expected to occur. The Kassler Water Treatment Plant has been closed since 1985 and no other Denver municipal water wells draw from the groundwater beneath or near AFP PJKS.
Private Drinking Water Wells	TCE--Most likely related to upgradient source, including AFP PJKS	Groundwater	No exposure. Potentially private wells located at residences	Ingestion, dermal contact, and inhalation	Private residents	Past, Present, Future: Two plumes have migrated from AFP PJKS to the Lockheed Martin Astronautics site. No private drinking wells are located in the affected area. TCE possibly related to AFP PJKS was detected in the Kassler area. No public health hazard exists for two upgradient and upstream domestic-use wells because conditions are not favorable for contaminant migration; even if contamination were to occur, the exposure should not result in adverse health effects.
Surface Water	Contaminants related to upgradient sources, including AFP PJKS	Surface Water	No exposure. Potentially South Platte River and the Chatfield Reservoir	Dermal contact while swimming, wading, boating, or fishing along the South Platte River or Chatfield Reservoir	Recreational users of the South Platte River and Chatfield Reservoir	Past, Present, Future: No TCE or other VOCs have been detected in the South Platte River samples. Therefore, swimming and other recreational uses of the South Platte River and the Chatfield Reservoir, into which it flows, are unlikely to result in adverse health effects.

Contaminant	Maximum Concentration (ppb)		Comparison Value
Contaminant	Alluvium	Bedrock	Concentration (ppb)	Reference
Benzene	38	34	1 5	CREG MCL
1,2-Dichloroethane (1,2-DCA)	18	ND	0.4 5	CREG MCL
trans-1,2-Dichloroethylene (trans-1,2-DCE)	1,300	110	200 100	RMEG MCL
1,1-Dichloroethylene (1,1-DCE)	24	ND	0.06 7	CREG MCL
Tetrachloroethylene (PCE)	7.7	5.6	0.7 5	CREG MCL
1,1,1-Trichloroethane (1,1,1-TCA)	870	3	200	MCL
Trichloroethylene (TCE)	11,000	8,900	3 5	CREG MCL
Vinyl Chloride	430	ND	0.7 2	EMEG MCL
Nitrate	72,000	39,000	10,000	MCL
N-nitrosodimethylamine (NDMA)	5	42	0.0007	CREG

Contaminant ^a	Concentration Range (ppb)	Frequency of Detections	Comparison Value
Contaminant ^a	Concentration Range (ppb)	Frequency of Detections	Concentration (ppb)	Reference
1,1,1-Trichloroethane (1,1,1-TCA)	6.2 - 6.7	2/94	200	MCL
Trichloroethylene (TCE)	5 - 36	21/101	3 5	CREG MCL