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HEALTH CONSULTATION

DEFENSE SUPPLY CENTER RICHMOND
[a/k/a DEFENSE GENERAL SUPPLY CENTER (DLA)]
CHESTERFIELD, CHESTERFIELD COUNTY, VIRGINIA


STATEMENT OF ISSUE

In May 2001, the Agency for Toxic Substances and Disease Registry (ATSDR) was requested bythe Virginia Department of Environmental Quality (VDEQ) to provide a public healthconsultation on the public health significance of environmental contaminants found in surfacewater at and near the Defense Supply Center Richmond (DSCR), formerly known as the DefenseGeneral Supply Center (DGSC). In this health consultation, ATSDR evaluates the potential risk to people who could be exposed to contaminants in surface water on or near DSCR in No Nameand Kingsland Creeks. The data on No Name and Kingsland Creeks were provided by VDEQand DSCR.

ATSDR previously completed a public health assessment (pha) for the U.S. Defense GeneralSupply Center Richmond, Chesterfield County, Virginia (CERCLIS No. VA3971520751) onApril 21, 1993 (ATSDR, 1993). The pha concluded the facility posed no apparent public health hazard.


BACKGROUND

The Defense Supply Center Richmond (DSCR) is a Defense Logistics Agency (DLA) federalfacility that comprises 631 acres in Chesterfield County, Virginia, approximately 12 miles southof the city of Richmond, Virginia. The DSCR has been managing and furnishing militarygeneral supplies to the Armed Forces and several federal civilian agencies since 1942. Currentoperations at the facility include the management and storage of military supplies, materialhandling, and storage of chemicals such as pesticides, herbicides, lubricants and petroleumproducts (Law, 2001a). As a result of past activities, environmental contamination exists at thefacility. The facility is listed on the United States Environmental Protection Agency's (EPA) National Priority List (NPL). The responsibility for facility environmental cleanup belongs tothe DLA, with oversight by the EPA and state regulatory agencies, such as VDEQ.

The area within a one-mile radius of DSCR is populated by 16,228 people. Of those residents,2,129 are children aged six and younger (U.S. Census, 1990, see Figure 1). The area to thenortheast and east of DSCR has been developed as both single family and multi-family housing. A housing subdivision called Rayon Park is located directly east of DSCR. Rayon Park consistsof 74 buildings, including duplexes and single-family homes. Most of the residents' homes havebeen served by the public water supply since June 1987. Some of the homes also have privategroundwater supply wells. Three homes and a rental duplex continued to use well water as theirdrinking water source. The residents did not hook up to the public water supply for financial andpersonal reasons. The rental unit was inadvertently not connected to public water until 2001. All four of these wells were tested in 2001 and no levels of organic pollutants tested for werefound.

The various cleanup sites at DSCR have been divided into 13 Operable Units (OU) and the PXGas Station. Operable Unit 6 (OU 6) consists of the Area 50/Open Storage Area/National GuardArea Groundwater. Historical activities at DSCR have caused contamination of the groundwaterfrom solvents and metals. There are two contamination plumes extending from Area 50eastward through the National Guard Area. Contamination in the upper aquifer is primarilyvolatile organic compounds (VOCs), as well as some semi-volatile organic compounds (SVOCs)and metals. In general, these same contaminants are also found in the lower aquifer. Area 50 isa former landfill suspected to be the source of the groundwater contamination. The groundwaterin the upper aquifer moves toward and discharges into No Name Creek, but the primary sourceof flow for No Name Creek is surface water runoff from DSCR and the area west of DSCR(Law, 2001a). The primary source of flow for Kingsland Creek is surface water runoff from thearea west of DSCR. Operable Unit 9 (OU 9) consists of the Interim Action System for OU 6. OU 9 is a groundwater treatment system that was installed to remove volatile organiccompounds from groundwater via air stripping. Residual vapors are treated with activatedcarbon. The remedial system is in place to intercept, remove, and treat impacted groundwaterfrom both the upper and lower aquifers on-site, prior to migrating off site and coming intocontact with No Name Creek (Law, 2001a).

The Virginia Department of Environmental Quality (VDEQ) Piedmont Regional Officeconducted surface water sampling of No Name Creek near DSCR on May 14, May 21, and May30, 2001. Three samples and one field blank were taken on May 14. Two samples were takenon May 21. Two samples and two field blanks were taken on May 30. DSCR conducted surfacewater sampling of No Name Creek on May 14, May 16, and July 20, 2001. Seven samples, oneequipment blank, and one trip blank were taken on May 14. Six samples were taken on May 16. Seven samples and one equipment blank were taken on July 20. Data was also reviewed from aJune 13, 2001 sampling event at No Name Creek. Barium was the only compound detected inthe June sampling event. Barium was found at 29 ppb, which is lower than the barium detectedin the May and July sampling events, and also lower than the comparison value. Therefore, theJune sampling results are not discussed in this consultation.

DSCR conducted surface water sampling of Kingsland Creek on May 16, 2001. Four samples,one equipment blank, and one trip blank were taken on May 16. The No Name and KingslandCreek samples were analyzed for metals, volatile organic compounds, and semi-volatile organiccompounds. A list is of the chemicals sampled for is shown in Table 1. Appropriate qualityassurance and quality control procedures were used to validate the sampling data. An evaluation of the data is described in the discussion section.


DISCUSSION

ATSDR identifies and evaluates exposure pathways by considering how people might come intocontact with, or be exposed to, a contaminant. For a public health hazard to exist, people mustcome into contact with areas of contamination, and the amount of contamination must besufficient to affect human health. For the purpose of evaluating the public health impact ofchemical releases into the environment, it is critical to determine if people come into contactwith the chemicals. If so, the duration of the chemical contact is also important.

There are five elements of an exposure pathway: 1) Source of Contamination, 2) EnvironmentalMedia, 3) Point of Exposure, 4) Route of Exposure, and 5) Exposed Population. All five of theseelements must be present in order for there to be a completed exposure pathway. Operable Unitsat DSCR are examples of the source of contamination. The environmental media is surfacewater. The point of exposure would be the location at which human contact is made withcontamination. Most residences in the area neighboring DSCR are connected to the public watersupply, therefore the only point of exposure is surface water, such as No Name or KingslandCreeks. The route of exposure is the pathway through which contaminants enter the body. Theonly routes of exposure would be incidental ingestion or dermal contact with surface water. Theexposed population would be residents who come into contact with the creeks, especiallychildren.

In examining environmental data, ATSDR uses comparison values to select environmentalcontaminants for further evaluation. A comparison value is a concentration of a givencontaminant in soil, water, or air below which no adverse human health effects are expected tooccur. Most of the comparison values used in this public health consultation assume exposureover a 70-year lifetime, and ingestion of 2 liters of water per day for adults, and 1 liter per dayfor children. Comparison values have built-in safety factors to ensure that they are protective ofhuman health. ATSDR comparison values represent contaminant concentrations many timeslower than levels at which no effects were observed in experimental animals or humanepidemiologic studies. If contaminant concentrations are above comparison values, ATSDRfurther analyzes exposure variables (for example, duration and frequency), the toxicity of the contaminant, other epidemiology studies, and the weight of evidence for health effects.

Several comparison values were used in this public health consultation. Cancer Risk EvaluationGuides (CREG) are derived by ATSDR from the EPA Cancer Slope Factor. They represent anestimated concentration in water, soil, or air that would be expected to cause no more than oneexcess cancer in a million persons exposed over a lifetime. Maximum Contaminant Levels(MCL) represent contaminant concentrations that EPA deems protective of public health over alifetime (70 years) at an exposure rate of 2 liters of water per day. MCLs are enforceablestandards. Drinking Water Lifetime Health Advisories (LTHA) are derived by EPA from adrinking water equivalent level below which no adverse non-cancer health effects are expectedto occur. CREGs, MCLs, and LTHAs are intended for drinking water use over a 70 yearlifetime. A Reference Media Evaluation Guide (RMEG) is a concentration in air, soil, or waterbelow which non-cancer health effects are not expected to occur. RMEGs are derived fromEPA's reference dose or reference concentration, and are for chronic exposures. AEnvironmental Media Evaluation Guide (EMEG) is a concentration in air, soil, or water belowwhich no adverse non-cancer health effects are expected to occur. EMEGs are derived fromATSDR's Minimal Risk Level (MRL), and are expressed for acute, intermediate, and chronicexposures. Action Levels are the estimated contaminant concentrations in water which indicatethat additional evaluation is needed to determine whether action is required to eliminate orreduce exposure.

The water in No Name and Kingsland Creeks is not used for drinking water. In the case of NoName and Kingsland Creeks, the only exposure would be through incidental ingestion anddermal contact. Both of these exposures would be limited because of the short period of timespent in the creeks. Because of this, the comparison values used for evaluation are overlyprotective. They have been developed for the exposure route of ingestion of drinking water. Therefore they are also highly conservative for the dermal route of exposure. Additionally, thelow concentration of contaminants found in the creeks does not effectively cross the skin barrierinto the body.

The Virginia Department of Environmental Quality (VDEQ) Piedmont Regional Office andDSCR conducted surface water sampling of No Name and Kingsland Creeks in May and July2001. Table 1 shows the list of chemicals of various classes which were tested for in both NoName and Kingsland Creeks; such as metals, volatile organic compounds (VOCs), and semi-volatile organic compounds (SVOCs). Standard EPA procedures and analyses were used toevaluate the compounds. Samples taken from No Name and Kingsland Creeks were analyzed formany compounds, but very few were detected. Additionally, the frequency of detection was lowfor most of the detected compounds. Metals are common and expected in surface water. Metalsfrequently occur naturally both in groundwater and surface water.

VDEQ conducted surface water sampling of No Name Creek on May 14, May 21, and May 30,2001. DSCR conducted surface water sampling of No Name Creek on May 14, May 16, andJuly 20, 2001. Table 2 shows those compounds that were detected in No Name Creek inconcentrations above the methodological detection limits. Seven compounds detected in NoName Creek were found in concentrations above the most conservative drinking watercomparison values used by ATSDR for human health effects. The water in No Name Creek isnot used for drinking water. Exposure to water from No Name Creek would be through dermalcontact and incidental ingestion for a relatively short period of time. The seven compounds wereevaluated for incidental ingestion and dermal absorption exposure doses and then compared tohealth guidelines. Tables 4 and 5 show the estimated exposure doses for incidental ingestion anddermal absorption. All of the estimated exposure doses were well below available healthguidelines.

ATSDR estimated the human exposure doses from incidental ingestion and dermal absorption ofsurface water. The equations used to derive exposure doses can be found in Appendix A. Deriving exposure doses requires evaluating the concentrations of the contaminants to whichpeople may have been exposed, and how often and how long exposures to those contaminantsoccurred. Together, these factors help influence the individual's physiological response tochemical contaminant exposure and the potential for noncancer or cancer outcomes. In theabsence of exposure specific information, ATSDR applied several conservative assumptions todefine site-specific exposures as accurately as possible for people contacting contaminatedmedia.

The estimated exposure doses were used to evaluate potential noncancer effects associated withcontaminants detected in site media. When evaluating noncancer effects, ATSDR first comparedthe estimated exposure dose to standard toxicity values, including ATSDR's minimal risk levels(MRLs) and EPA's reference dose (RfDs), to evaluate whether adverse effects may occur. Thechronic MRLs and RfDs are estimates of daily human exposure to a substance that is likely to bewithout appreciable risk of adverse noncacer effects over a specified duration. The chronicMRLs and RfDs are conservative values, based on the levels of exposure reported in theliterature that represent no-observed-adverse-effects-levels (NOAEL) or lowest-observed-adverse-effects-levels (LOAEL) for the most sensitive outcome for a given route of exposure(e.g., dermal contact, ingestion). In addition, uncertainty (safety) factors are applied toNOAELs or LOAELs to account for variation in the human population and uncertainty involvedin extrapolating human health effects from animal studies. When comparing dermal absorptionexposure doses to health guidelines, a gastrointestinal (GI) factor is applied to the Oral RfD orOral MRL. This accounts for the difference in absorption through skin as compared to theabsorption through the gastrointestinal wall. If estimated exposure doses are greater than theMRL or RfD, ATSDR reviews the toxicological literature to determine the likelihood of adverseeffects. None of the exposure doses of contaminants detected in No Name Creek were greaterthan the MRLs or RfDs. ATSDR health guidelines are not available for lead or thallium, buttoxicological and epidemiological information is available.

The maximum thallium concentration found in surface water in No Name Creek was 2.0 ppb. Using this maximum concentration, ATSDR estimated that incidental ingestion of water fromNo Name Creek would result in an exposure dose of 8.90e-7 mg/kg/day for children, and 4.07e-7mg/kg/day for adults. EPA has RfDs for several thallium compounds. Each RfD covers aparticular compound and is based on animal studies for that compound. For example, the RfDfor thallium sulfate is based on a failure to observe harmful effects in rats that were administeredas much as 0.25 mg/kg/day of thallium by gavage. EPA divided this number by an uncertaintyfactor of 3000 to account for humans being more sensitive than rats to thallium, for somehumans being more sensitive than others, and for a lack of chronic toxicity data. This gave EPAan RfD of 8.0e-5 mg/kg/day. The thallium dose that did not cause toxicity to rats (i.e., 0.25mg/kg/day) was 280,000 times higher than the maximum exposure dose that ATSDR estimatedfor surface water ingestion from No Name Creek, despite the fact that ATSDR used veryconservative assumptions to estimate dose. If more realistic exposure assumptions were used,estimated doses would be even lower. Therefore, ATSDR concluded that ingestion of thalliumin surface water from No Name Creek is not expected to result in adverse human health effects.

The maximum lead concentration found in surface water in No Name Creek was 35.8 ppb. Using this maximum concentration, ATSDR estimated that incidental ingestion of water fromNo Name Creek would result in an exposure dose of 1.59e-5 mg/kg/day for children, and 7.29e-6mg/kg/day for adults. ATSDR determined that incidental ingestion for 365 days at the highestdetected concentration of lead in water (35.8 ppb) does not pose a public health hazard. ATSDRestimated blood lead levels using the Integrated Exposure Uptake Biokinetic Model (IEUBK) forLead for children, adults, and fetuses (EPA, 1996). The Centers for Disease Control andPrevention (CDC) have determined that health effects are more likely to be observed if actualblood lead levels are at or above 10 micrograms per deciliter (g/dl). Using the IEUBK model,estimated blood lead levels were found to be below 10 g/dl for all populations. Health effectsare not expected from exposure to the levels of lead and thallium in No Name Creek.

DSCR conducted surface water sampling of Kingsland Creek on May 16, 2001. Table 3 showsthose compounds that were detected in Kingsland Creek in concentrations above methodologicaldetection limits. Although some compounds were detected, the analytical results showed alldetected compounds in Kingsland Creek to be below the most conservative drinking watercomparison values used by ATSDR for human health effects.


CHILD HEALTH INITIATIVE

ATSDR is committed to protecting children's health. ATSDR recognizes that infants andchildren may be more sensitive than adults to environmental exposure in communities faced withwater, soil, air, or food contamination. This sensitivity is the result of several factors, including: 1) children are smaller than adults, resulting in higher doses of chemical exposure per unit bodyweight; 2) children's bodies may be more sensitive to the effects of chemical exposures. Children have developing body systems which can sustain permanent damage if toxic exposuresoccur during critical growth stages. Because of these sensitivities, ATSDR uses healthguidelines that are protective for children. ATSDR did not find contaminants present at levels that would present a public health hazard to children.


CONCLUSIONS

ATSDR's evaluation of the data does not indicate a current human health hazard exists fromexposure to surface water. Surface water sampling of No Name Creek detected sevencompounds above the most conservative comparison values for drinking water. No compoundswere detected in Kingsland Creek above comparison values. These comparison values areintended for drinking water. No Name and Kingsland Creeks are not used for drinking water. Any exposure to compounds in surface water would be through short-term incidental ingestionand dermal contact. Maximum single detection values were used to estimate exposure doses forthe seven compounds detected above comparison values in No Name Creek. All of theestimated exposure doses are below health guidelines. Therefore, adverse health effects are not expected from exposure to surface water.


RECOMMENDATIONS

1) If future groundwater monitoring results on the installation indicate that concentrations areincreasing and might affect the creeks, periodically monitor No-Name and Kingsland Creeksadjoining the installation. Use appropriate quality assurance and quality control procedures tovalidate the sampling data.

2) If any extraordinary releases of groundwater from the treatment system or other sources ofchemicals occur that could impact No Name and Kingsland Creeks, surface water samplingshould be conducted to evaluate the potential effect on public health.


TABLES

Table 1.

Chemicals Sampled for in No Name and Kingsland Creeks
Chemical Defense Supply Center Richmond (Law Environmental Inc.) Virginia Department of Environmental Quality
Metals
Arsenic X X
Cadmium X X
Lead X X
Antimony X  
Selenium X X
Silver X  
Aluminum X  
Barium X  
Beryllium X  
Calcium X  
Cobalt X  
Chromium X X
Copper X X
Iron X X
Potassium X  
Magnesium X  
Manganese X X
Molybdenum X  
Sodium X  
Nickel X X
Vanadium X  
Zinc X X
Mercury X X
Thallium X  
Volatile Organic Compounds
Acetone X  
Benzene X X
Bromobenzene X  
Bromochloromethane X X
Bromodichloromethane X X
Bromodichloropropane   X
Bromoform X X
Bromomethane X X
2-Butanone X  
n-Butylbenzene X X
sec-Butylbenzene X X
tert-Butylbenzene X X
Carbon disulfide X  
Carbon tetrachloride X X
Chlorobenzene X X
Dibromochloromethane X  
Chloroethane X X
2-Chloroethylvinyl ether   X
Chloroform X X
Chloromethane X X
2-Chlorotoluene X X
4-Chlorotoluene X  
p-Chlorotoluene   X
Dibromochloromethane   X
1, 2-Dibromo-3-chloropropane X X
1, 2-Dibromoethane X  
Dibromomethane X  
1, 2-Dichlorobenzene X X
1, 3-Dichlorobenzene X X
1, 4-Dichlorobenzene X X
Dichlorodifluoromethane X  
1, 1-Dichloroethane X X
1, 2-Dichloroethane X X
cis-1, 2-Dichloroethene X X
trans-1, 2-Dichloroethene X X
1, 1-Dichloroethene X X
Dichlorofluoromethane   X
1, 2-Dichloropropane X X
1, 3-Dichloropropane X X
2, 2-Dichloropropane X X
cis-1, 3-Dichloropropene X X
trans-1, 3-Dichloropropene X X
1, 1-Dichloropropene X X
Ethylbenzene X X
1, 2-Ethylenedibromide   X
Hexachlorobutadiene X X
2-Hexanone X  
Isopropylbenzene X X
4-Isopropyltoluene   X
p-Isopropyltoluene X  
Methylene chloride X X
4-Methyl-2-pentanone X  
Methyl t-butyl ether (MTBE)   X
Napthalene X X
n-Propylbenzene X X
Styrene X X
1, 1, 1, 2-Tetrachloroethane X X
1, 1, 2, 2-Tetrachloroethane X X
Tetrachloroethene X X
Toluene X X
1, 2, 3-Trichlorobenzene X X
1, 2, 4-Trichlorobenzene X X
1, 1, 1-Trichloroethane X X
1, 1, 2-Trichloroethane X X
Trichloroethene X X
Trichlorofluoromethane X X
1, 2, 3-Trichloropropane X X
1, 2, 4-Trimethylbenzene X X
1, 3, 5-Trimethylbenzene X X
Vinyl chloride X X
m-Xylene & p-Xylene X  
o-Xylene X  
Xylenes (total) X X
Semi-Volatile Organic Compounds
Acenaphthene X X
Acenaphthylene X X
Anthracene X X
Benzo(a)anthracene X X
Benzo(b)fluoranthene X X
Benzo(k)fluoranthene X X
Benzoic acid X  
Benzo(ghi)perylene X X
Benzo(a)pyrene X X
Benzyl alcohol X  
Benzylbutylphthalate   X
bis(2-Chloroethoxy)methane X X
bis(2-Chloroethyl)-ether X X
bis(2-Chloroisopropyl)ether X X
bis(2-Ethylhexyl)phthalate X X
4-Bromophenyl phenyl ether X X
Butyl benzyl phthalate X  
n-Butyl benzyl phthalate   X
4-Chloroaniline X  
4-Chloro-3-methylphenol X X
2-Chloronaphthalene X X
2-Chlorophenol X X
4-Chlorophenyl phenyl ether X X
Chrysene X X
Dibenz(a,h)anthracene X X
1, 2, 5, 6-Dibenzanthracene   X
Dibenzofuran X  
Di-n-butyl phthalate X X
1, 2-Dichlorobenzene X X
1, 3-Dichlorobenzene X X
1, 4-Dichlorobenzene X X
3, 3'-Dichlorobenzidine X  
2, 4-Dichlorophenol X X
Diethyl phthalate X X
2, 4-Dimethylphenol X X
Dimethyl phthalate X X
4, 6-Dinitro-2-methylphenol X  
2, 4-Dinitrophenol X X
2, 4-Dinitrotoluene X X
2, 6-Dinitrotoluene X X
Di-n-octyl phthalate X X
Fluoranthene X X
Fluorene X X
Hexachlorobenzene X X
Hexachlorobutadiene X X
Hexachlorocyclopentadiene   X
Hexachloropentadiene X  
Hexachloroethane X X
Hexachloroethate   X
Hexachloropropene X  
Indeno(1, 2, 3-cd)pyrene X X
Isophorene   X
Isophorone X X
2-Methyl-4, 6-dinitrophenol   X
2-Methylnaphthalene X  
2-Methylphenol X  
3-Methylphenol & 4-Methylphenol X  
Naphthalene X X
2-Nitroaniline X  
3-Nitroaniline X  
4-Nitroaniline X  
Nitrobenzene X X
2-Nitrophenol X X
4-Nitrophenol X X
N-Nitrosodimethylamine   X
N-Nitrosodiphenylamine X X
N-Nitrosodi-n-propylamine X X
Pentachlorophenol X X
Penanthrene   X
Phenanthrene X X
Phenol X X
Pyrene X X
1, 2, 4-Trichlorobenzene X X
2, 4, 5-Trichlorophenol X  
2, 4, 6-Trichlorophenol X X


Table 2.

Chemicals Detected in No Name Creek
Chemical Chemical Concentration Range (ppb) Frequency of Detections Frequency above Standards Drinking Water Standards (ppb) Standard Used
Metals
Aluminum65.2-20107/27020000IntermediateEMEG-Child
Antimony3.51/2704ChronicRMEG-Child
Arsenic8.0-12.43/2730.02CREG
Barium44.4-74.613/270700ChronicRMEG-Child
Cadmium2.1-3.42/2722ChronicEMEG-Child
Calcium*4540-4950012/27NANANA
Chromium2.62/270100LTHA
Cobalt1.4-3.27/270100IntermediateEMEG-Child
Copper11.9-1174/2701300Action Level
Iron*175-2280015/27NANANA
Lead3.2-35.84/27215Action Level
Magnesium*1530-491013/27NANANA
Manganese 45.1-29315/270500ChronicRMEG-Child
Molybdenum3.31/27050ChronicRMEG-Child
Nickel2.5-4.52/270100LTHA
Potassium*157-1090014/27NANANA
Sodium*5900-1230013/27NANANA
Thallium1.7-2.02/2710.5LTHA
Vanadium2.1-4.63/27030IntermediateEMEG-Child
Zinc12.3-84.714/2703000ChronicEMEG-Child
Volatile Organic Compounds
Acetone0.66-0.792/2703000ChronicRMEG-Child
n-Butylbenzene0.191/27NANANA
sec-Butylbenzene0.261/27NANANA
Chlorobenzene0.141/270200ChronicRMEG-Child
Chloroform0.201/2706CREG
Trichloroethene0.26-2117/2725MCL
1,4-Dichlorobenzene0.191/27075LTHA
cis-1,2-Dichloroethene0.28-4514/27070LTHA
bis (2-Ethylhexyl)phthalate6.41/2713.0CREG
Tetrachloroethene0.54-2.18/27010LTHA
Toluene0.361/270200IntermediateEMEG-Child
1,2,4-Trimethylbenzene0.801/27NANANA
1,3,5-Trimethylbenzene0.201/27NANANA
Vinyl Chloride1.5-6.14/2730.03CREG

* = NA-Not Available. Many metals do not have drinking water standards because they are common and naturally occurring.
Reference: VDEQ, 2001. Law, 2001b.


Table 3.

Chemicals Detected in Kingsland Creek
Chemical Chemical Concentration Range (ppb) Frequency of Detections Frequency above Standards Drinking Water Standards (ppb) Standard Used
Metals
Barium34.1-57.14/40700ChronicRMEG-Child
Calcium*4210-61704/4NANANA
Copper8.21/401300Action Level
Iron*1430-23204/4NANANA
Potassium*1900-25404/4NANANA
Magnesium*1590-22004/4NANANA
Manganese23.8-82.74/40500ChronicRMEG-Child
Sodium*8050-121004/4NANANA
Zinc12.7-17.42/403000ChronicEMEG-Child
Mercury*0.0791/4NANANA
Volatile Organic Compounds
cis-1,2-Dichloroethene1.1-2.93/4070LTHA
Tetrachloro-ethene0.43-0.442/4010LTHA
1,1,1-Trichloroethane0.66-0.682/40200LTHA
Trichloroethene1.2-2.43/405MCL

* = NA-Not Available. Many metals do not have drinking water standards because they are common and naturally occurring.
Reference: Law, 2001b.


Table 4.

Water Incidental Ingestion Exposure Doses
Compound Contaminant Concentration (ppb) Exposure Dose-Child (mg/kg/ day) Exposure Dose-Adult (mg/kg/ day) Frequency above Guideline Health Guide-line (mg/kg/day) Health Guideline Used
Arsenic12.45.52e-62.52e-603.0e-4Oral RfD
Cadmium3.41.51e-66.92e-702.0e-4ChronicOral MRL
Lead35.81.59e-57.29e-6NANANA
bis (2-Ethylhexyl)phthalate6.42.85e-61.30e-601.0e-2Inter-mediateOral MRL
Thallium2.08.90e-74.07e-7NANANA
Trichloro-ethene21.09.35e-64.27e-602.0e-1AcuteOral MRL
VinylChloride6.12.72e-61.24e-603.0e-3Oral RfD


Table 5.

Dermal Absorption Exposure Doses
Compound Contaminant Concentration (ppb) Exposure Dose-Child (mg/kg/ day) Exposure Dose-Adult (mg/kg/ day) Frequency above Guideline Health Guide-line (mg/kg/day) Health Guideline Used
Arsenic12.41.21e-56.11e-606.0e-5Oral RfDx GIFactor
Cadmium3.43.32e-61.67e-604.0e-5Oral MRLx GIFactor
Lead35.83.50e-61.76e-6NANANA
bis (2-Ethylhexyl)phthalate6.42.06e-41.04e-408.0e-3Inter-mediateOral MRLx GIFactor
Thallium2.01.96e-69.85e-7NANANA
Trichloro-ethene21.04.72e-32.38e-301.6e-1Oral MRLx GIFactor
VinylChloride6.14.35e-52.19e-502.4e-3Oral RfDx GIFactor


Demographic Statistics
Figure 1. Demographic Statistics


PREPARER OF REPORT

Agency for Toxic Substances and Disease Registry
Department of Health Assessment and Consultation
Federal Facilities Assessment Branch
Defense Section A

Katherine E. Hanks, Environmental Health Scientist


REFERENCES

Agency for Toxic Substances and Disease Registry (ATSDR). 1993. Public Health Assessment: U.S. Defense General Supply Center. Richmond, Chesterfield County, Virginia. CERCLIS No.VA3971520751. Atlanta: U.S. Department of Health and Human Services, April 21, 1993.

Law Engineering and Environmental Services, Inc. (Law). July 2001a. Draft Data Summary forOperable Unit 9 Pump and Treat System Defense Supply Center Richmond Richmond, VA;Prepared for Defense Logistics Agency U.S. Army Engineering and Support Center Huntsville.

Law Engineering and Environmental Services, Inc. (Law). 2001. No Name Creek and KinglandCreek Surface Water Test Results.

U.S. Bureau of the Census. 1990.

Virginia Department of Environmental Quality (VDEQ). 2001. No Name Creek Surface Water Test Results.


APPENDIX A: EXPOSURE DOSE EQUATIONS

Exhibit 1.

Water Incidental Ingestion Exposure Dose Equation
Exposure doses from incidental ingestion of water can be calculated as follows:
    ED = (C * IR * EF) / BW
Default Incidental Ingestion Water Intake Rates3
 
.02 L/day - adult
.01 L/day - child
 
Note:
L/day - liters per day
where,    
ED = exposure dose (mg/kg/day)
C = contaminant concentration (mg/L)
IR = intake rate of contaminated water (L/day)
EF = exposure factor (unitless)
BW = body weight (kg)

 

Exhibit 2.

Water Dermal Contact Exposure Dose Equation
Exposure doses from dermal contact with water can be calculated as follows:
    ED = (C * P * SA * ET * CF) / BW
Default Dermal Exposure Values
50th Percentile Body Part-Specific Surface Area for Males
(square centimeters [cm2])
Age (years) Arms Hands Legs

3<4 960 400 1800
6<7 1100 410 2400
9<10 1300 570 3100
18-70 2300 820 5500
Source: EPA 1997
where,    
ED = exposure dose (mg/kg/day)
C = contaminant concentration (mg/L)
P = permeability coefficient (cm/hr)
SA = exposed body surface area (cm2)
ET = exposure time (hours/day)
CF = conversion factor (1 L/1,000 cm3)
BW = body weight (kg)


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