PUBLIC HEALTH ASSESSMENT
TYNDALL AIR FORCE BASE
PANAMA CITY, BAY COUNTY, FLORIDA
Based on the results of our site visit and a review of the data and information currently available,ATSDR concludes that there are no past, current, or future exposure situations at TAFB that posea public health hazard.ATSDR reached this conclusion by reviewing the IRP sites, solid wastemanagement units, and other environmental data. From this review, we identified and evaluatedfour potential exposure situations as shown in Table 1: (1) exposure to DDT-contaminated fish inFred Bayou; (2) exposure to lead in soils at the Tyndall Elementary School; (3) exposure to leadin tap water at 2451 Lincoln Drive in the Bay View Housing area; and (4) exposure tocontaminated surface soils and soil gas at Wherry Landfill. Our overall public health conclusionis no apparent public health hazard. Details of these exposure situations are summarized inTable 2 and discussed in the following sections. Conclusion categories are explained inAppendix C.
|Exposure Situations||Conclusion Category|
|Exposure to DDT-contaminated fish in Fred Bayou (past, present, and future)||No Apparent Public Health Hazard|
|Exposure to lead in soils at the Tyndall Elementary School (past, present, and future)|
|Past exposure to lead in tap water at 2451 Lincoln Drive, Bay View Housing|
|Past exposure to contaminated surface soils or soil gas at Wherry Landfill||Indeterminate Public Health Hazard|
|Situation Name||Contaminants||Exposure Pathways Elements||Time||Comments|
|Source||Environmental Media||Point of Exposure||Route of Exposure||Exposed Population|
|Exposure to DDT Contaminated Fish in Fred Bayou||DDT, DDD, DDE||Sediment/ |
|Fish||Consumption of fish caught in Fred Bayou||Ingestion||People consuming fish caught in Fred Bayou, 250 to 500 people per year.||Past, current, future||No Apparent Public Health Hazard|
|Exposure to Lead in Soils at the Tyndall Elementary School||Lead||Contaminated soil and lead pellets from former military training||Soil||School yard||Ingestion||Children, teachers, lawn care workers, parents (850 students enrolled per year with 50 to 75 teachers, administrators and other staff).||Past, current, future||No Apparent Public Health Hazard|
|Exposure to Lead in Tap Water||Lead||Water distribution system, plumbing||Water||Faucets||Ingestion||Military Family (estimated at four people)||Past||No Apparent Public Health Hazard|
|Wherry Landfill||Not known at this time||Wherry Landfill||Potentially soil and soil gas/indoor air||Potentially homes and fields at Bay View Housing||Potentially ingestion and inhalation||Residents at Bay View Housing||Past||Indeterminate Public Health Hazard, homes adjacent to the landfill are vacant awaiting demolition. Bay View Housing is scheduled for demolition by 2008 for area to become runway buffer.|
Eating DDT contaminated fish from Fred Bayou was determined to present no apparent publichealth hazard to recreational and subsistence consumers in the past, currently and in the futurefor two reasons: (1) concentrations of DDT, DDD, and DDE in the fish evaluated with expectedexposure scenarios were below levels of concern; and (2) warning signs are posted in FredBayou discouraging people from consuming fish caught there.
Fred Bayou (also known as Shoal Point Bayou, Site No.OT029, or IRP Site 29) is a large tidalcreek on the north side of TAFB (Figure 1). The bayou is approximately 3,750 feet long and 300to 400 feet wide. The Bayou flows into East Bay at its northern end. East Bay is part of the St. Andrew Bay estuarine system that opens up to the Gulf of Mexico near Panama City, Florida. Two drainage ditches from the base flow into Fred Bayou at its southern end. The ditches drainportions of the flightline and the following areas:
IRP Site 5
6000 Area Landfill
IRP Site 14 POL Area A
IRP Site 16 Shell Bank Fire Training Area
IRP Site 36 6000 Area Construction Debris Landfill
Old Shell Pile/Old Pesticide Building
The discharge from the southwestern ditch is regulated under a discharge permit issued by EPAon January 26, 1977 (National Permit Discharge Elimination System [NPDES] No. F1003740). ATSDR found no permit violations since 1997 in EPA's database (EPA 1999).
Fred Bayou is used as a waterway for barges, tugboats, and small ships to access the base. Themost common cargo transported in the bayou is bulk petroleum fuels and sand/gravel materials. Private boats also enter the bayou for recreation and fishing.
The investigations of Fred Bayou began with studies of sediment by the U.S. Fish and Wildlife Service. The Fish and Wildlife Service sampled and analyzed sediment from Fred Bayou in 1985 and 1990. Subsequently, TAFB completed studies in 1993, 1995, 1996, and 1997 that included the sampling and analysis of sediment, water, biota (fish and macroinvertebrates), subsurface soil, and groundwater along with an evaluation of human health risk (Rust 1993a; Rust 1996; Rust 1998). TAFB continues to investigate Fred Bayou to determine the source of contamination, identify and evaluate potential clean-up options, and to evaluate the ecological risk. The source of contamination has not been confirmed. The main contaminants are the pesticides DDT, DDD, and DDE. A summary of the water and sediment sampling is provided in Appendix C and discussed in the following sections. A summary of the biota sampling results is presented in Appendix D. A description of the chemicals is provided in Appendix E. The contaminated groundwater and subsurface soils are not discussed here because the contamination is below ground surface and in remote areas and in areas where public access is prohibited. Sediment data are discussed because of the potential bioaccumulation of contaminants from sediment to fish. TAFB is conducting additional sediment and biota sampling and analysis under a remedial investigation (RI). The RI will include a baseline risk assessment which is scheduled to be completed by October 2000.
a. Biota Sampling and Analysis
TAFB collected and analyzed fish from Fred Bayou three times, once each in 1994, 1995, and1997. In 1994, gulf flounder fillets were analyzed for DDT, DDD, and DDE. In 1995, fillets ofblack drum, sheepshead, southern flounder, sand trout, and spotted sea trout and composites ofhogchoker, pinfish, and blue crab were analyzed for DDT, DDD, and DDE. The highestconcentrations of DDT, DDD, and DDE were detected in the same sand trout sample: 140 partsper billion (ppb) of DDT; 590 ppb of DDD; and 410 ppb of DDE.
In 1997, fillets of black drum, gulf flounder, sheepshead, silver seatrout, and spotted seatroutalong with composite samples of longnose killifish, pinfish, sailfin mollys, tidewater silversides,and fiddler crabs were sampled and analyzed for 21 pesticides and 12 congeners ofpolychlorinated biphenyls (PCBs). DDT, DDD, and DDE concentrations in these samples werelower than the 1995 samples. No other pesticides were detected. PCBs were also not detected.
For the purposes of this report, only those fish species typically consumed by humans areconsidered further. Therefore, longnose killifish, sailfin mollys, tidewater silversides, and fiddlercrabs are not discussed further. The Public Health Risk Evaluation and Conclusions sectiondiscusses the risk from consumption of contaminated fish.
b. Sediment Sampling
For ATSDR's public health evaluation, it is preferable to have analysis of the chemicalcontaminants in the fish. However, the current analytical data set on fish includes only DDT,DDD, DDE, other pesticides, PCBs, and mercury. As an indirect indicator of other contaminantsthat might be in the fish, ATSDR evaluated sediment samples collected in Fred Bayou.
Sediment samples in Fred Bayou were collected six times. The first two sets of samples werecollected by the Fish and Wildlife Service as part of a general environmental contaminantsevaluation of the greater St. Andrew Bay. In 1985, the Fish and Wildlife Service analyzed theFred Bayou sediments for DDE, DDD, DDT, PCBs, polycyclic aromatic hydrocarbons (PAHs),and metals, including mercury. Five subsamples were collected and composited. DDT wasmeasured at 4,600 g/kg, DDD at 1730 g/kg and DDE at 380 g/kg (dry weight basis, 5samples, isomers 2,4' and 4,4' added together). Individual PAH compounds were also analyzedwith the sum of the ten detected PAH compounds equal to 861 g/kg (dry weight). Total PCBswere reported at 3361 g/kg (dry weight).
In 1990, the Fish and Wildlife Service analyzed 28 additional samples from Fred Bayou forDDT, DDD, and DDE and found results similar to those found in the 1985 sampling.
As part of the DOD Installation Restoration Program, TAFB and its contractors sampled thesediments and water in Fred Bayou in 1992, 1995, 1996, and 1997. In 1992 and 1995, TAFBanalyzed sediment for DDT, DDD, and DDE. The highest concentrations detected were 12,000g/kg DDT, 2,600J g/kg DDD (J=estimated), and 1,100J g/kg DDE. Surface water was alsosampled for DDT, DDD, and DDE in 1992 and these compounds were not detected above thedetection limit of 0.1 g/L.
In 1996 and 1997, TAFB analyzed sediment for volatile organics, semivolatile organics, metals,pesticides, and PCBs. Again, DDT, DDD, and DDE were detected. In addition, carbondisulfide, chlordane, chloromethane, heptachlor, PAHs, phthalates, and metals were detected. Chloromethane was detected in 1 of 24 samples at 15 g/kg and carbon disulfide in 1 of 11samples at 8.8 g/kg. The PAHs detected were benzo(a)pyrene (detected in 1 of 24 samples at370 g/kg), fluoranthene (1 of 24 samples, 600 g/kg), penanthrene (1 of 24 samples, 390g/kg), and pyrene (3/24 samples; maximum 1,400 g/kg; mean 917 g/kg). The phthalatesdetected were bis(2-ethylhexyl)phthalate (3/24 samples, mean 90 g/kg) and diethylphthalate(1/24 samples, 340 g/kg). Chlordane and heptachlor were analyzed in the fish and therefore arenot discussed here.
Compounds detected in the sediment would be a concern if they bioaccumulate and if they aredetected in many locations above background concentrations. Chloromethane and carbondisulfide do not significantly bioaccumulate (Hazardous Substance Database 1999; ATSDR1994). In the case of PAHs, they do bioaccumulate and could be a problem. Detection of PAHs,in predominately one sample (FBSED97-1, 1 of 24 samples collected in 1997) may indicate thatPAH contamination is localized in one area. The public health implications of PAHs arediscussed in the next section.
In the case of metals, TAFB analyzed sediment for 22 metals with 19 metals detected. Metalsare naturally occurring in the environment and their presence is expected. To evaluate metals,we compared the concentration of sediments in the bayou to background samples. Thebackground samples were collected by TAFB from locations approved by EPA. These locationsare, Chatterson Bayou, Farmdale Bayou, Freshwater Bayou, Pearl Bayou, and Smack Bayou. The background concentrations are similar to the metal concentrations in Fred Bayou. Therefore,concentrations of metals detected are not a concern.
For the public health implications of exposure to contaminated fish, we reviewed three items ofinformation:
- Fish data collected from 1994, 1995, and 1997
- The Technical Memorandum, Human Health Risk Evaluation (RUST 1996)
- Sediment data for potential bioaccumulative compounds not analyzed in the fish.
The discussion of this data is in two parts. The first part discusses the fish tissue data and theTechnical Memorandum. The second part discusses PAHs and sediment data.
a. Fish Tissue Data and the Human Health Risk Evaluation
The Technical Memorandum, Human Health Risk Evaluation (HHRE, RUST 1996) evaluated the human health risk from consumption of contaminated fish based on the 1994 and 1995 fish tissue data. In June 1997, ATSDR reviewed and commented on the HHRE and submitted comments to TAFB. Our review comments are discussed briefly here and presented in their entirety in Appendix F. In our review, we concurred with the assumptions and evaluation except for one item: the chemical compounds analyzed were limited to DDT, DDD, and DDE but the fish could have been contaminated with other chemicals. In June 1997, data on additional chemicals were collected with the additional collection and analysis of flounder, black drum, pinfish, sand trout, and spotted sea trout for compounds other than DDT, DDD, and DDE. Other non-game fish collected included silversides and fiddler crab. These fish were analyzed for 21 pesticides and 12 PCBs (analyzed as Aroclors). DDT, DDD, or DDE were the only pesticides detected. PCBs were not detected. The concentrations of the pesticides detected in these fish were similar or lower than concentrations in the samples collected in 1994 and 1995. This means that the results of the HHRE were still applicable because the three sampling events produced similar results.
Based on current scientific literature, levels of contaminants found in fish in Fred Bayou have notbeen shown to cause adverse health effects in children or adults. The HHRE evaluated thecancer risk and noncancer hazards from ingesting DDD, DDE, and DDT in black drum, gulfflounder, sheepshead, southern flounder, sand trout, and spotted sea trout. The assumptions usedin the HHRE are summarized in Appendix G. The assumptions in the risk evaluation were veryprotective. Adult recreational fish consumers were assumed to ingest 50 g/day (children 6.2g/day) of the same fish everyday for 30 years (6 years for children). The ingestion rates areapproximately the 95th percentile for saltwater anglers in the gulf. This means that 95 % of thepopulation ingests less fish per year. Even more protective is the assumption of eating the samespecies of fish for 30 years. This is very unlikely. The HHRE overestimates the exposures to bevery protective of human health.
The risk calculations in the HHRE show that the cancer risks are within EPA's acceptable rangeof 1 in 1,000,000 to 1 in 10,000. For noncancer, the hazard indices were all well below 1.0except for sand trout for a child and adult at subsistence ingestion rates (1.90 and 2.45,respectively) and an adult at recreational ingestion rates (1.22). The hazard index is the ratio ofthe calculated dose divided by the reference dose (RfD). When the calculated dose is above thereference dose, the hazard index is greater than one. For a hazard index of 1.9, the calculateddose is 1.9 times greater than the reference dose. Reference doses serve as a screening tool tohelp public health professionals determine where potential health effects may be of concern andwhere pertinent toxicologic information should be evaluated. When the calculated dose is abovethe reference dose, health effects are not necessarily likely but a cause for further investigation.
The reference dose is set below the lowest observed adverse effect level (LOAEL) or noobserved adverse effect level (NOAEL) to ensure safety. A LOAEL is the lowest dose at whichan adverse health effect is seen in a particular study. These studies usually involve animal testingand human epidemiologic data. A NOAEL is the highest dose from which a study did not findany adverse health effects. For DDT, DDD, and DDE, the reference dose is set at a value 100times below a NOAEL. The calculated doses for subsistence ingestion rates of fish from FredBayou fall 2.5 times above the reference dose but 40 times below the NOAEL.
ATSDR considered the reference dose, NOAEL, and the calculated dose in making a conclusionabout the public health implications of contaminated fish in Fred Bayou. Although the calculateddose is above the reference dose, it is 40 times below the NOAEL. In addition, the calculateddose is based on very conservative consumption rates. More realistic consumption rates wouldreduce the calculated dose closer to or below the reference dose. Hence, ATSDR considers anypast exposure not likely to result in any adverse health effects in children and adults.
The estimated calculated exposures overestimate the true exposure. To ensure additional safetyfor any current or future exposure, TAFB has posted warning signs in the bayou discouragingconsumption of fish. The sign reads:
"This area is under evaluation for elevated levels of DDT. Frequent regular consumption of fish from this area isdiscouraged. Children, pregnant or nursing women, and theelderly may be at greater risk. For further information contactpublic affairs at 283-2983."
b. Polycyclic aromatic Hydrocarbons and Sediment Data
This section evaluates the polycyclic aromatic hydrocarbons (PAHs) found in the sediment in Fred Bayou. PAHs bioaccumulate and hence could appear in fish. Because the fish tissue was not analyzed for PAHs, ATSDR evaluated the potential health risk based on the sediment analysis and the possible transport of PAHs from sediments to fish. This evaluation could be completed through transport modeling or through comparison to existing sediment concentrations that were determined acceptable. ATSDR took the latter approach.
For these acceptable concentrations (screening values), ATSDR used the publication"Developing Health-Based Sediment Quality Criteria for Cleanup Sites: A Case Study Report"(Washington State Department of Ecology, December 1997, Publication Number 97-114). Thisreport developed Human Health Sediment Criteria for Puget Sound based on consumption ofseafood using site-specific biota-sediment accumulation factors (BSAFs). Since site-specificBSAFs are not available for Fred Bayou, we used the BSAFs referenced in the report. The BSAFfor PAHs was 0.38 which is reasonable for fish since the BSAF data gathered by the US ArmyEngineers for PAHs in oysters and clams averaged 0.34 (Army 1999).
The sediment screening values in the Washington State report are based on eating 42 grams/dayof seafood with a cancer risk of 1 in a million and noncancer calculated dose less than thereference dose. For the sum of PAHs, the report used toxicity equivalency factors and calculatedscreening value was 330 g/kg, normalized to total organic carbon. In the case of sedimentsample FBSED97-1 (the sample in Fred Bayou with the highest PAH concentration), the totaltoxicity equivalency factor for the sum of the individual PAHs is 435 g/kg. Normalizing thisvalue to the total organic carbon.value of 49000 ppm (4.9% in sample FBSED97-1) results intotal organic carbon normalized value of 88.9 g/kg. Normalizing the values is done becausesediments with higher amounts of total organic carbons retain more organic contaminants withless contaminants available to the biota. This PAH value of 88.9 g/kg is 3.7 times lower thanthe ATSDR screening value and hence, not a public health concern.
One major assumption this comparison is based on is the representativeness of the one samplefor PAH concentrations in the bayou. A more appropriate approach would be to take a weightedconcentration of PAH values from the bayou, even though 22 sediment samples show no PAHs. However, ATSDR used the single highest value as a protective measure. Hence, ATSDRconcludes that the PAHs in the sediment are not a health hazard.
Based on the evaluation of over-protective ingestion estimates of DDT, DDD, and DDE, the factthat warning signs are posted to discourage eating fish from Fred Bayou, and the relative lowconcentrations of PAHs as compared to screening values, ATSDR considers that theconsumption of contaminated fish from the bayou in the past, present, or future poses noapparent public health hazard to recreational and subsistence consumers.
a. Actions Taken and Proposed
- TAFB has sampled sediments and fish in Fred Bayou and investigated potentialsources of DDT contamination. Based on the fish data, TAFB has completed aHuman Health Risk Evaluation.
- TAFB has posted warning signs in the bayou to discourage catching andconsuming fish in Fred Bayou and produced information brochure describing thecontamination for distribution to anglers.
- ATSDR reviewed and commented on the Human Health Risk Evaluation (June 3, 1997)
- ATSDR reviewed and commented on TAFB's Information Brochure (May 8, 1997)
- TAFB will be revising the Human Health Risk Evaluation based on additionaldata collected from the Installation Restoration Program investigations. Additionally, they will be revising the informational brochure based, in part, oncomments received from ATSDR.
- TAFB is currently conducting additional studies of the bayou under a remedialinvestigation which is scheduled to be completed by October 2000. TAFB willreevaluate the health risks when this new information is available.
No additional actions are needed to protect public health.
Lead pellets found in surface soil at Tyndall Elementary School do not present a public healthhazard to children who attended school in the past, children currently attending the school, orchildren attending the school in the future. Overall, lead levels in samples collected in theschool yard were low. The highest lead levels detected were from locations outside the fencedarea or beside the gate to the front entrance on Highway 98. The lead levels in the playgroundareas are low and not likely to cause adverse health effects in children or adults.
The Tyndall Elementary School is located off U.S. Highway 98. Approximately 850 studentsfrom pre-kindergarten to fifth grade attend this school. About 90% of the students are frommilitary families. The school and school grounds occupy approximately 20 acres; the property isfenced and a front gate leads to U.S. Highway 98. A second gate also leads to Highway 98. Theplaygrounds at the school are south and to the west of the school buildings and are within thefenced area.
The Army used the area currently occupied by the elementary school as a gunnery range in the1940s. In May 1992, Tyndall Elementary School personnel and students found lead pellets in thesoils of the school grounds. TAFB sampled the soils in the school yards on May 11 and 12,1992, and concluded that the lead levels were not a public health concern. As explained in thefollowing section, ATSDR concurs with this assessment.
TAFB sampled the Tyndall Elementary School grounds for lead in 1992. They collected 34samples, 30 within the fenced area and 4 outside the fence. The concentrations ranged from 7.2mg/kg to 20,000 mg/kg. The 20,000 mg/kg sample was taken from an area beside the front gate,a grass-covered area that is not part of the playground. It is unlikely that any children play in thisarea. The second highest concentration was 680 mg/kg. This sample was taken outside the rearfence in back of the building, an area unlikely to be visited by children. Children are very unlikely to be exposed to soil lead at these two areas. The third highest concentration, 340mg/kg, was found in the southeastern corner of the school grounds, which is a part of theplayground. The average concentration within the school yard, including 340 mg/kg butexcluding the 20,000 mg/kg, 680 mg/kg values, and three other samples outside the fence is 97mg/kg (±29.5 at the 95% confidence level, a range of 6.3 mg/kg to 340 mg/kg).
The average lead level found in the soil and the 95% upper confidence level are below thescreening values of 400 mg/kg and 130 mg/kg (see the table below). The screening value of 400mg/kg was devised by EPA Region 9 using an EPA Model (Integrated Exposure UptakeBiokinetic Model for Lead in Children-IEUBK, EPA 1998). The screening value of 130 mg/kgwas devised by the state of California as reported by EPA (EPA 1998). The 400 mg/kg level hasbeen considered acceptable by the State of Florida (Saranko et al 1999). Therefore, exposure tolead in soils at Tyndall Elementary school is not a public health hazard.
|Mean||95% Upper Confidence level||Screening Values|
|97 mg/kg||127 mg/kg||400 mg/kg||130 mg/kg|
1 Values exclude samples taken outside the perimeter fence of the school and the sample collected beside the main front gate.
The source of high lead levels detected beside the gate at the front entrance on Highway 98 couldbe from past automobile exhaust when lead was a common component in gasoline. This sourcehowever, would not account for some of the high levels outside the fence in the back of theschool. Regardless of the source, the levels of lead in the soils accessible to children is not apublic health hazard.
a. Actions Taken
TAFB responded readily to the identification of lead in the school yard by sampling the soils. After analyzing the results, TAFB concluded that no further action was needed.
ATSDR concurs with TAFB's conclusion that no further action is needed.
Exposure to lead in tap water at 2451 Lincoln Drive does not pose a public health hazard. Although the base is in compliance with EPA's Lead and Copper Rule, ATSDR had concernsthat this home, tested at 60 g/L lead in 1992, would pose a health hazard for children orpregnant women. However, subsequent sampling in 1997 resulted in levels below concern. Inaddition, the Bay View Housing area is scheduled for close out and demolition in the next threeyears.
In 1992, TAFB began sampling the tap water of houses at the base for lead and copper inaccordance with EPA's Lead and Copper Rule. One house, at 2451 Lincoln Drive in the BayView Housing area tested at 60 g/L lead in 1992. During our visit in January 1997, baserecords indicated that this house was not retested.
The Bay View houses were built in the late 1940s. These houses are scheduled for demolition inthe year 2001 to 2002 timeframe for flight operations/resident safety constraints andmodernization purposes. Drinking water to these houses and other housing on the base issupplied from the Bay County Water System.
Lead and copper in drinking water systems are regulated in a treatment technique which requireswater systems to take tap water samples from sites with lead pipes, copper pipes with lead solder,or have lead service lines. EPA then requires the water to be treated when the samples exceed1.3 mg/L for copper and 0.015 mg/L for lead in more than 10% of the houses. Bay Countyrequires TAFB to sample the water supply at the home taps for lead and copper every three yearsin approximately 20 homes. The most recent sampling episode was in 1998. All results in 1998were below the 1.3 mg/L for copper and 0.015 mg/L for lead indicating that water treatment wasnot necessary and that the water is safe (i.e., not a public health hazard).
The Lead and Copper Rule relies on statistical sampling and results for compliance. Municipalities can be in compliance when up to 10% of the samples have concentrationsexceeding the action levels. Hence, TAFB, with one of 20 houses exceeding the action level in1992, was in compliance with the Lead and Copper Rule after the results from this one homewere reported. However, ATSDR had public health concerns because the house at 2451 LincolnDrive exceeded the screening value for lead.
Although the base was in compliance with EPA's Lead and Copper Rule, ATSDR reviewed leadand copper sampling records during our site visit and identified the house at 2451 Lincoln Drivethat was found to have 60 g/L of lead in the tap water.
Lead levels above 15 g/L could pose a health hazard for children or pregnant womenconsistently drinking water with elevated levels over time. As a result of our recommendationsfor further sampling, the Bioenvironmental Engineering Flight resampled this location onJanuary 31, 1997. The new data for lead and copper levels, shown below, are belowconcentrations of concern.
|Bathroom||Kitchen||Levels of Concern|
|Lead||<1 g/L||4 g/L||15 g/L|
|Copper||4 g/L||104 g/L||1,300 g/L|
Subsequent to our recommendations and these sampling results, TAFB reported that a follow-upsample was collected at 2451 Lincoln Drive on February 10, 1993 with a lead level of 3 g/L (deVenoge 2000).
As a result, ATSDR concludes that there is no apparent public health hazard.
a. Actions Taken
In 1997, TAFB resampled the tap water of one house that had elevated lead concentrations in the1992 sampling.
ATSDR recommends no further action since the current lead and copper concentrations arebelow levels of concern. There is no apparent public health hazard.
The Wherry Landfill is located in the Bay View housing area (formerly called Wherry IIhousing). In 1998 and 1999, subsurface and surface soil and groundwater samples were takenfrom locations on top of and adjacent to the landfill. Low levels of pesticides were found in thesoils. These soils do not pose a public health hazard. In addition to these samples, ATSDRrecommends soil gas sampling and a report providing additional information about the landfillfor evaluating potential exposure pathways for past public health hazards for people living inthis neighborhood. ATSDR has classified Wherry Landfill as an indeterminate public healthhazard at this time for past exposure. Potential current and future exposure have been reducedsignificantly and possibly eliminated (i.e. do not pose a hazard) because many of the housesadjacent to the landfill have been vacated awaiting demolition. The entire Bay View Housingarea is scheduled for closure by 2008 because the area will be used as a natural buffer zone forthe runway.
The Wherry Landfill is located in the Bay View Housing area on-base. The landfill was usedfrom approximately 1943 until 1948. Figure 2 shows the location of the landfill area within thehousing area. The Installation Restoration Program Records search states that the landfill wasused for disposal of general refuse including mess hall wastes. The landfill consisted of trenches,one-half mile long and 3 to 4 feet deep (CH2M Hill, 1981). The Bay View Housing area was builtin 1951 with 179 single-family, single-story houses. The houses are built on slabs and have 2 to 3 bedrooms. During the mid-1970s, 25 houses wereremoved because of foundations settling and cracking (CH2M Hill, 1981). The landfill may havecontributed to the settling. The following houses were removed:
Addresses on Lincoln Drive
2421, 2423, 2425, 2427, 2429, 2430, 2431, 2432, 2433, 2434,
2435, 2436, 2437, 2438, 2439, 2441
Addresses on Coolidge Avenue
2516, 2518, 2520, 2526, 2528
Addresses on Monroe Avenue
Addresses on Taylor Avenue
Figure 3 shows the housing area before removal of the 25 houses.
The closest currently existing house is 50 feet from the "perceived" boundary of the landfill; 9houses are within 200 feet and 21 houses are within 400 feet.
TAFB has scheduled the entire housing area for closure by 2008, or sooner, if funding forreplacement housing can be secured. As of February 2000, a demolition project was underway toremove all but 45 houses. The houses bordering the old landfill were scheduled for demolitionduring this project and have been vacated (de Venoge 2000 and Fugitt 2000).
In 1998 and 1999, TAFB sampled surface soil, subsurface soil and groundwater at and beside theWherry Landfill. This sampling does not provide ATSDR with sufficient information to rule outall exposure pathways.
In 1999, surface soil samples were also collected from the Bay View Housing area. Pesticides that exceeded screening values were detected in the surface soils. These screening values,however, are based on 30 years or more of exposure. Because the families living in these housesare serving tours of duty of approximately 3 years, the pesticides in the soils are not a publichealth hazard. Table 3 provides more detail on the sampling data, and Appendix H provides ourcomments on the sampling.
Groundwater samples exceeded screening values for metals, but this is not a public health hazardbecause the groundwater is not being used as a drinking water source. The landfill was not sampled for subsurface soil gases. Landfills may be a source of carbondioxide, carbon monoxide, methane, and volatile organic compounds. These gases could migratethrough the subsurface to adjacent homes via undisturbed soils or through soils in disturbed areassuch as utility lines.
a. Actions Taken
TAFB sampled the soil above and beside the landfill for volatile organics, semivolatile organics,pesticides, PCBs and metals. TAFB also sampled the soil in the Bay View Housing area.
Potential current and future exposure to the landfill has been reduced significantly because thehomes adjacent to the landfill have been vacated and are scheduled for demolition.
Because of the sampling and analytical limitations, ATSDR recommends that TAFB completethe following to evaluate past potential exposure pathways at the Wherry Landfill.
- Provide information on the "perceived" boundaries of the landfill includinginformation about the houses that were removed and any photographs orgeophysical work. If necessary, revise the maps with the correct boundaries of thelandfill.
- Sample subsurface soil gas around the periphery of the landfill to determine ifcontaminated soil gas is present and migrating to the adjacent houses. If soil gasis present, determine the soil gas migration pathways and plume extent. If housesare located in these pathways or over the gas plumes, the indoor air of thosehouses should be sampled.
- Take additional groundwater elevation readings to determine seasonalgroundwater flow directions. Reevaluate the current theorized groundwater flowdirection and provide information about the tidal influence on groundwaterelevations. Provide information about wells in the vicinity to determine whetherthe flow direction is relevant to exposure and to confirm that there are no drinkingwater wells that could be contaminated.
ATSDR conducted interviews of local, state, and other federal government officials to identifyany community health concerns. During these interviews, no community health concerns werebrought to our attention.
If you have concerns you would like to relay to ATSDR, please direct them to the followingaddress.
Program Evaluation, Records, and Information Services Branch
Re: Tyndall Air Force Base
ATSDR, Division of Health Assessment and Consultation
1600 Clifton Road, MSE-56
Atlanta, GA 30333
Questions may also be directed to Robert Safay, the ATSDR regional representative in Region 4,at 404-562-1782 or to the ATSDR information line at 888-42ATSDR or 888-422-8737. Pleasemention that you are calling about Tyndall Air Force Base.