PUBLIC HEALTH ASSESSMENT
U.S. AIR FORCE PLANT NO. 4 (GENERAL DYNAMICS)
FORT WORTH, TARRANT COUNTY, TEXAS
*The SMR (standardized mortality ratio) is defined as the number of observed deaths divided by the number ofexpected deaths. The latter are based on race-, sex-, and age-specific cancer mortality rates for Texas during theperiod 1986-1995.
**To determine if the SMR was significantly different from one (1.00), we calculated a 95% confidence intervalfor each type of cancer. The 95% confidence interval indicates the range in which we would expect the SMR tofall 95% of the time. If the confidence interval includes one (1.00), the observed to expected are not statisticallysignificant; the SMR is within the range that would be expected based on the mortality experienced by the entirestate.
Prepared by: Cancer Registry Division, Texas Department of Health 7/10/97
|AFP4||Air Force Plant 4 (Formerly General Dynamics)|
|ATSDR||Agency for Toxic Substances and Disease Registry|
|CERCLA||Comprehensive Environmental Response, Compensation and Liability Act of 1990|
|CoPCs||Contamints of Potential Concern|
|CREG||Carcinogenic Risk Evaluation Guide|
|DOD||Department of Defense|
|DOE||Department of Energy|
|EMEG||Environmental Media Evaluation Guide|
|EPA||U.S. Environmental Protection Agency|
|ESL||Effects Screening Level - Screening levels established by the TNRCC|
|FDA||Food and Drug Administration|
|HAC||Health Assessment Comparison Value|
|HOD||Health Outcome Data|
|IRP||Installation Restoration Program|
|LTHA||Lifetime Health Advisory|
|MCL||Maximum Contaminant Level|
|MCLG||Maximum Contaminant Level Goal|
|mg/kg||Milligrams per Kilogram|
|mg/L||Milligrams per Liter|
|MRL||Minimal Risk Level|
|NAS||Naval Air Station (Formerly Carswell Air Force Base)|
|NARF||Nuclear Aerospace Research Facility|
|NPL||National Priorities List|
|PA/SI||Preliminary Assessment/Site Inspection|
|PAHs||Polycyclic Aromatic Hydrocarbons|
|PHA||Public Health Assessment|
|PMCLG||Proposed Maximum Contaminant Level Goal|
|ppbv||parts per billion volume|
|QA/QC||Quality Assurance/Quality Control|
|RI/FS||Remedial Investigation/Feasibility Study|
|RMEGs||Reference Dose Based Media Evaluation Guides|
|ROD||Record of Decision|
|SARA||1986 Superfund Amendments and Reauthorization Act|
|VOC's||Volatile Organic Compounds (example - Benzene)|
|Semi-VOCs||Semi-Volatile Organic Compounds (example - Polycyclic Aromatic Hydrocarbons)|
|SMR||Standardized Mortality/Morbidity Ratio|
|TDH||Texas Department of Health|
|TNRCC||Texas Natural Resource Conservation Commission|
|TPH||Total Petroleum Hydrocarbons|
|USGS||United States Geological Service|
|µg/L||Micrograms per Liter|
|VOCs||Volatile Organic Compounds|
|Aqueduct||A conduit for water|
|Aquifer||A layer of permeable rock containing water|
|Aquitard||Impenetrable barrier between aquifers|
|Background||Concentrations detected in an area that cannot be attributed to the site|
|Bioaccumulate||To build up in the tissue of an animal, human, or plant|
|Contaminant||An undesirable element that causes impurity or pollution|
|Dermal||Of or relating to the skin|
|Expected||An epidemiologic term referring to the number of cases that we would expect to find in a specific population based on the number that we see in a reference population|
|Facility||Something built to perform a specific function|
|Groundwater||Water beneath the ground surface|
|Infiltrate||To cause to permeate something by penetrating its pores or interstices|
|Ingest||To take in, to eat|
|Lipophilic||Having an affinity for lipid (fat)|
|Migrate||To move from one place to another|
|Observed||An epidemiologic term referring to the actual number of cases found in a specific population|
|Plume||An elongated, mobile area of contaminated media; usually beginning at a contamination source and indicating the spread of contamination|
|Seepage||A quantity of fluid that has oozed slowly from the ground to the surface|
|Seine||Type of net used to catch fish|
|Site||A place or spatial location of an actual or planned structure or set of structures|
|Terrace Alluvial||A stream deposit of unconsolidated sediments produced when a stream downcuts a flood plain or valley floor|
|Topographic high||An area that is higher than other nearby areas|
|Transect||To cut across at a right angle|
|Landfill No. 1|
A six-acre site that was usedfrom 1942 to approx. 1966for disposal of general refuse,
|The area was closed in 1966 and paved for employee parking. During the RI, TCE (nd to 0.11 mg/kg) and toluene (nd to350 mg/kg) were detected. Benzo(a)pyrene was detected (1.1to 62 mg/kg) below the asphalt cover and was attributed to theasphalt.||On the basis of the baseline risk assessmentand because the benzo(a)pyrene appears to bederived from the overlying asphalt, the soil atthis location does not pose an unacceptablerisk to humans. The selected remedy for thislocation is no action.|
|Landfill No. 2|
An eight-acre site used fromthe early 1940s to early1960s for the disposal ofconstruction rubble, plaster,lumber, and tires.
|There were no indications that hazardous materials weredisposed at this location. The area is now grass covered. In1989, toluene was detected in one of 39 samples at aconcentration of <1.0 mg/kg.||On the basis of these analytical results, the soilat this location does not pose an unacceptablerisk to human health or the environment. Theselected remedy for this location is no action.|
|Fire Training Area No. 2|
A 50-ft diameter earthen ringlocated north of Landfill No.1.
|This area was used for semiannual fire-training exercisesbetween 1955 and 1965. It is currently overlain with asphaltfrom the West Parking Lot. TCE and 1,2-DCE were detectedat concentrations < 1.0 mg/kg.||On the basis of the baseline risk assessment,the soil at this location does not pose anunacceptable risk to human health or theenvironment. The selected remedy for thislocation is no action.|
|Fire Training Area No. 3|
Located near the westernedge of AFP4 and northeastof Landfill No. 4
|This area was used for fire-training exercises in the 1960's. Itis currently grass covered. The exact location of this site couldnot be determined. Laboratory analysis of groundwatersamples indicate no elevated concentrations of sitecontaminants.||On the basis of available information, theselected remedy for this location is no action.|
|Fire Training Area No. 4|
Reported to be at thenorthern tip of AFP4.
|Fire department personnel report that no firefighting exerciseswere ever conducted in this area, The exact location could notbe determined but personnel reported that the site receivedclean-fill from a foundation excavation.||On the basis of available information, theselected remedy for this location is no action.|
|Fire Training Area No. 5|
A 35 ft-by-45 ft shallow pitlocated at the south-centralboundary of AFP4.
|It was used for fire training exercises in the mid 1960's. Lowconcentrations of VOCs and Semi-VOCs (<2.0 mg/kg) weredetected in soil boring samples.||On the basis of the baseline risk assessment,the soil at this location does not pose anunacceptable risk to human health or theenvironment. The selected remedy for thislocation is no action.|
|Fire Training Area No. 6|
A 50-square foot gravel linedarea approximately 2 feetdeep, surrounded by anearthen berm.
|This area was the primary fire department training area fromthe late 1960s to 1982. Interim remedial action wasperformed at this site to remove oil/fuel contaminated soil. Subsequent soil sampling has detected low concentrations ofVOCs and Semi-VOCs (generally less than 1.0 mg/kg; twoSemi-VOCs were detected at 3.0 mg/kg).||On the basis of the baseline risk assessment,the soil at this location does not pose anunacceptable risk to human health or theenvironment. The selected remedy for thislocation is no action.|
|Chrome Pit No. 1 |
An unlined earthen pit thatreceived liquid wastes duringthe early 1940s.
|Building 181 was constructed on this site. Analytical resultsindicate the presence of chromium in the soils around Building181; however, the concentrations are below the upperbackground limit for the Western United States.||Given the limited usage of the pit and itspresence beneath a building, the selectedremedy for this area is not action.|
|Chrome Pit No. 2 |
An unlined earthen pitlocated near the southwestcorner of the AssemblyBuilding/ Parts Plant
|This pit reportedly received liquid chrome wastes during themid-1940s; however, the actual location could not bedetermined.||Since this site could not be located, theselected remedy for this area was no action.|
|Chrome Pit No. 3 |
A large earthen pit (55 ftwide x 165 ft long x 15 ftdeep) located in the southernportion of AFP4 west ofBuilding 12.
|It was operational from 1957 to 1973 and received chromesludge, dilute metal solutions, and other unidentified liquids. An interim action was conducted in Dec. 1983 and Jan. 1984to excavate and remove approximately 8,900 cubic yards ofsoil. Following the excavation and removal, soil samplingdetected the presence of TCE in one sample at a concentrationof 4.8 mg/kg.||On the basis of the low concentrations oforganic compounds detected following theremoval of the soil, this location does not posean excess risk to human health or theenvironment. The selected remedy for thisarea is no action.|
|Die Yard Chemical Pits|
Three pits (approximately 20ft wide x 90 ft long x 10 ftdeep) located in the southernportion of AFP4.
|In 1962, this area was graded and the entire area was pavedfor parking. In 1983 and 1984, they excavated the originaldie pits, and 1,100 cubic yards of contaminated soil wereremoved. Post excavation confirmatory sampling detectedVOCs at concentrations between non-detect and 5.6 mg/kg. Subsequent sampling has detected VOCs at concentrations lessthan 0.5 mg/kg.||On the basis of these data, the soil in this areadoes not pose an excess risk to human healthand the environment. The selected remedy forthis area is no action.|
|Fuel Saturation Area No. 1|
Soil located immediatelywest of the AssemblyBuilding/Parts Plant,partially beneath Building14.
|Soil at this location reportedly became saturated with JP-4leaking from underground piping during the 1970s and early1980s. Ethylbenzene and benzene were detected in three of 45samples at concentrations less than 1.0 mg/kg. One samplecontained Semi-VOCs (less than 2.7 mg/kg).||The baseline risk assessment determined thatthe soil contamination at this site does notcause an excess risk to human health and theenvironment. The selected remedy for thisarea is no action.|
|Fuel Saturation Area No. 2|
Soil surrounding anunderground pipeline in thenorthwest portion of AFP4.
|Originally reported as a potential site because of reports ofsaturated soil along an underground pipeline in the northwestportion of AFP4. No contaminants of concern were detectedin soil from this area.||On the basis that no contaminants pose a riskto human health or the environment, theselected remedy for this area is no action.|
|Fuel Saturation Area No. 3||Investigated because of reports of leaking underground fuellines in the area. Acetone, benzene, and ethylbenzene weredetected at concentrations below 1.0 mg/kg. Semi-VOCs weredetected at concentrations between 0.85 and 5.9 mg/kg.||The baseline risk assessment determined thatthe soil contamination at this site does notcause an excess risk to human health and theenvironment. The selected remedy for thisarea is no action.|
|Former Fuel Storage Area|
The site of a former above-ground 1.000,000-gallon JP-4 fuel storage tank located inthe southwest portion ofAFP4.
|The tank was used from the early 1940s to 1962 when it wasremoved from the site and relocated. Soil beneath the tankreportedly contained jet fuel at the time the tank was removed. In 1991, soil samples were collected from four borings thatwere drilled around a monitoring well installed at the site. NoVOCs, semi-VOCs, or other contaminants of concern wereidentified in those samples.||On the basis of no contaminants that pose arisk to human health or the environment, theselected remedy for this area is no action.|
This area is located in thenorth-central portion ofAFP4.
|The lines were used to transport xylene, 2-butanone, andkerosene from 1942 until 1944. This area was identified asrequiring investigation on the basis of personnel accounts ofreported leaks. In 1985, two soil samples collected duringinstallation of a monitoring well were analyzed for xylene and2-butanone; neither compound was detected. VOCs ingroundwater samples did not exceed their respective MCLs.||This area was designated as No Further Actionby the Plant 4 Technical Review Committeebefore the start of the remedial investigation.|
|Nuclear Aerospace ResearchFacility|
Approximately 120 acreslocated on at the northern tipof AFP4.
|This area was the site of three atomic reactors used between1953 and 1974 for research and development activities In1974, this facility was decontaminated and dismantled. High-level and low-level radioactive components were segregatedand shipped to regulated off-site disposal areas. In 1989,alpha radiation in soil samples ranged from 6.7 to 12.4picocuries per gram (pCi/g). Beta radiation ranged from 10.0to 23.1 pCi/g. Gamma radiation was not measured directlybut samples were analyzed for cesium-137, which was notdetected. The alpha and beta activities were deemed typical ofnormal background levels encountered in undisturbed soil. In1991, six sediments samples were collected from Lake Worthnear the NARF facility site. These samples were tested forcesium-137, radium-226, thorium-230, and uranium. Theconcentrations measured were deemed typical of normalbackground levels encountered in most undisturbed soil.||On the basis of these data, the NARF site doesnot pose a risk to human health or theenvironment. The selected remedy for thisarea is no further action.|
|West Compass Rose|
A 150-square foot arealocated in the northernportion of AFP4.
|This area was included as a possible site on the basis ofpersonnel recollections of past surface spills. In 1985, 24shallow borings were drilled in the area. Organic vapors weredetected in samples from 3 of the 24 borings. One sample wassubmitted for VOC analyses, but no contaminants weredetected. In 1991, an additional boring was drilled and nofuel hydrocarbons were present in the soil samples from thisboring.||On the basis of these data, the West CompassRose site does not pose a risk to human healthor the environment. The selected remedy forthis area is no further action.|
|Jet Engine Test StandLocated in the northernportion of AFP4.||This area was included as a possible area of concern on thebasis of employee reports of jet fuel and gasoline in a sumpnear the site. In 1986, 2 of 5 samples contain fuelhydrocarbons at concentrations of 1,700 and 1,300 mg/kg. In1991, 2 of 7 samples contained low concentrations (between1.1 and 5.1 mg/kg) of semi-VOCs.||On the basis of these data, it was determinedthat this area does not pose an excess risk tohuman health or the environment and theselected remedy for the area is no action.|
|Underground Storage TanksNo. 19 and No. 20|
Two 12,000-gallon-capacitytanks formerly located in thesouth-central portion ofAFP4.
|No. 19 was used to store 2-butanone; No. 20 was used to store2-butanone, ethylbenzene, and xylene. Both tanks wereremoved in 1988 and the area beneath the tanks wasexcavated. In 1991, 27 soil samples were collected.Concentrations of less than 1.0 mg/kg. were detected for 2-butanone, xylene, and ethylbenzene.||On the basis of the analytical data, these areasdo not pose an excess risk to humans or theenvironment. The selected remedy is noaction|
|Underground Storage TanksNo. 24A and 24B|
Two 8,000-gallon tankslocated side-by-side in thesouth-central portion ofAFP4.
|These tanks were excavated and removed in 1988. Lowconcentrations of organics (<1.0 mg/kg) were detected inconfirmatory soil samples. In 1991, nine soil samples werecollected and no organic contaminants of concern weredetected in any of these samples.||On the basis of the analytical data, these areasdo not pose an excess risk to humans or theenvironment. The selected remedy is noaction|
|Underground Storage TankNo 25A|
Located adjacent to the JetEngine Test Stand in thenorthern portion of AFP4.
|This area formerly contained two vertical underground tanksused to store JP-4. The tanks were removed in 1988. In1991, eleven soil samples were submitted for analysis;ethylbenzene was detected at concentrations less than 1.0mg/kg and 2-methylnaphthalene was detected at 3.9 mg/kg.||On the basis of the analytical data, these areasdo not pose an excess risk to humans or theenvironment. The selected remedy is noaction|
|Underground Storage TankNo. 30 |
A 2,000-gallon steel tank,formerly located in thenorthern portion of AFP4.
|This tank was used to store JP-4. The tank was installed in1956 and removed in 1988. In 1991, eight samples werecollected from this area; no VOCs or semi-VOCs weredetected in these samples.|