PUBLIC HEALTH ASSESSMENT
LONE STAR ARMY AMMUNITION PLANT
TEXARKANA, BOWIE COUNTY, TEXAS
ENVIRONMENTAL CONTAMINATION / PATHWAYS ANALYSIS / PUBLIC HEALTH IMPLICATIONS
Exposure to or contact with chemical contaminants drive the ATSDR public health assessment process. The release or disposal of chemical contaminants into the environment does not always result in exposure or contact and chemicals only have the potential to cause adverse health effects if people actually come into contact with them. People may be exposed to chemicals by breathing, eating, or drinking a substance containing the contaminant or by skin (dermal) contact with a substance containing the contaminant.
When people are exposed to chemicals, the exposure does not always result in adverse health effects. The type and severity of health effects that may occur in an individual from contact with contaminants depend on the toxicologic properties of the contaminants; how much of the contaminant to which the individual is exposed; how often and/or how long exposure is allowed to occur; the manner in which the contaminant enters or contacts the body (breathing, eating, drinking, or skin/eye contact); and the number of contaminants to which an individual is exposed (combinations of contaminants). Once exposure occurs, characteristics such as age, sex, nutritional status, genetics, life style, and health status of the exposed individual influence how the individual absorbs, distributes, metabolizes, and excretes the contaminant. These factors and characteristics influence whether exposure to a contaminant could or would result in adverse health effects.
To assess the potential health risks associated with contaminants at this site we compared contaminant concentrations to health assessment comparison (HAC) values. HAC values are media specific contaminant concentrations that are used to screen contaminants for further evaluation. Non-cancer HAC values are called environmental media evaluation guides (EMEGs) or reference dose media evaluation guides (RMEGS) and are respectively based on ATSDR's minimal risk levels (MRLs) or EPA's references doses (RfDs). MRLs and RfDs are estimates of a daily human exposure to a contaminant that is unlikely to cause adverse non-cancer health effects. Cancer risk evaluation guides (CREGs) are based on EPA's chemical specific cancer slope factors. CREGs estimate an excess lifetime cancer risk of one-in-one-million for an exposed population. We used standard assumptions to calculate appropriate HAC values [10]. Exceeding a HAC value does not imply that a contaminant represents a public health threat, but suggests that the contaminant warrants further consideration. In some instances, we compared contaminant concentrations in water to EPA's maximum contaminant levels (MCLs), EPA's lifetime health advisory levels (LTHA), or EPA secondary drinking water standards. MCLs are chemical specific maximum concentrations allowed in water delivered to the users of a public water system; they are considered protective of public health over a lifetime (70 years) of exposure at an ingestion rate of two liters per day. MCLs may be based on available technology and economic feasibility. Although MCLs only apply to public water supply systems, we often use them to help assess the potential public health implications of contaminants found in water from other sources. LTHAs represent contaminant concentrations that EPA considers to be protective of noncarcinogenic health effects during a lifetime (70 years) of exposure. Secondary drinking water standards control contaminants that affect the aesthetic qualities of water.
In preparing this Public Health Assessment, ATSDR/TDH relied on the information provided in the referenced documents. The Agency assumed that adequate quality assurance and quality control measures were followed with regard to chain-of-custody, laboratory procedures, and data reporting. The validity of the analyses and the conclusions drawn in this document are determined by the availability and reliability of the referenced information.
The majority of the environmental sampling data discussed in this document were collected for the United States Department of the Army by their contractor AGEISS Environmental, Inc during the Phase IV Remedial Investigation of the ODA. Data collection and analysis were conducted under the regulatory oversight of, and in cooperation with, EPA and the TNRCC. These data were collected between November 1995 through August 1996 [2]. The EPA has approved quality assurance and quality control (QA/QC) criteria contained in the referenced site investigation documents. The EPA also has overseen all aspects of the remedial investigation to ensure that all QA/QC standards were met.
Table 1 lists the types of compounds tested for in the ODA. Table 2 lists the maximum detected concentration of each contaminant found in each of the media sampled. Contaminants reported below their respective detection limits are not listed in the table. ATSDR comparison values for each of the contaminants also are listed in the table. When ATSDR comparison values are not available, EPA's screening values or other comparison values are referenced. Inclusion of a contaminant in the table or the fact that a contaminant exceeds a comparison value does not imply that a contaminant represents a threat to public health.
Table 1. Types of Chemicals Tested for at the Old Demolition Area at Lone Star
| Chemicals |
Media Sampled |
|||||||
| Surface Water |
Sediment |
Soil |
Groundwater |
Source |
Air (no data) |
|||
| 0' | 2' | > 5' | ||||||
| Volatile Organics
Semivolatile Organics Explosives Metals |
X |
X |
X |
|
X |
X |
|
|
Table 2. Contaminants Detected in Various Media at
Lone Star Old Demolition Area
| Contaminated Media | Potential Contaminants of Concern | Maximum Detected Concentration | ATSDR Comparison Value* |
| Sediment | Aluminum Barium Cobalt Copper Iron Manganese Nickel Vanadium Zinc Arsenic Lead Selenium Mercury |
6,240 mg/kg 180.5 mg/kg 34.8 mg/kg 14.85 mg/kg 8,090 mg/kg 189 mg/kg 17.5 mg/kg 12.25 mg/kg 101.2 mg/kg 5 mg/kg 19.4 mg/kg 0.995 mg/kg 0.319 mg/kg |
700 - 100,000 mg/kg Background 4000 mg/kg RMEGchild1 Not available Not available Not available 300 mg/kg RMEGchild 1,000 mg/kg RMEGchild 200 mg/kg intEMEGchild2 20,000 mg/kg RMEGchild 20 mg/kg EMEGchild3 400 mg/kg EPA Screening level 100 mg/kg EMEGchild 100 mg/kg intEMEGchild |
| Soil | Nitroglycerine Tetryl 2,4,6-Trinitrotoluene Aluminum Barium Beryllium Cadmium Chromium Cobalt Copper Iron Manganese Molybdenum Nickel Silver Thallium Vanadium Zinc Arsenic Lead Selenium Mercury |
230 mg/kg 6.1 mg/kg 2.2 mg/kg 16,800 mg/kg 110 mg/kg 1.07 mg/kg 1.35 mg/kg 80.4 mg/kg 18.4 mg/kg 797 mg/kg 86,500 mg/kg 1,610 mg/kg 2.99 mg/kg 12.3 mg/kg 2.1 mg/kg 9.23 mg/kg 110.2 mg/kg 308 mg/kg 6.78 mg/kg 62 mg/kg 3.2 mg/kg 50 mg/kg |
Not available Not available 30 mg/kg RMEGchild; 400 mg/kg RMEGadult4 700 - 100,000 mg/kg Background 4000 mg/kg RMEGchild 300 mg/kg RMEGchild 50 mg/kg RMEGchild 300 mg/kg RMEGchild Not available 50 mg/kg Background Not available 300 mg/kg RMEGchild 300 mg/kg RMEGchild 1,000 mg/kg RMEGchild 300 mg/kg RMEGchild 5 mg/kg RMEGchild; 60 mg/kg RMEGadult 200 mg/kg intEMEGchild 20,000 mg/kg RMEGchild 20 mg/kg EMEGchild 400 mg/kg EPA Screening level 100 mg/kg EMEGchild 100 mg/kg intEMEGchild |
| Source material | 2,4,6-Trinitrotoluene Tetryl Aluminum Antimony Arsenic Barium Cadmium Chromium Cobalt Copper Iron Lead Manganese Mercury Molybdenum Nickel Selenium Thallium Zinc |
80,500 mg/kg 178,000 mg/kg 83,600 mg/kg 53.3 mg/kg 31.0 mg/k 37.9 mg/kg 114 mg/kg 145 mg/kg 15.3 mg/kg 450,000 mg/kg 278,000 mg/kg 6,290 mg/kg 4,360 mg/kg 60.4 mg/kg 51.8 mg/kg 188 mg/kg 8.18 mg/kg 30 mg/kg 223,000 mg/kg |
30 mg/kg RMEGchild; 400 mg/kg RMEGadult |
| Surface water (all concentrations were below background metals concentrations) |
Aluminum Barium Iron Manganese Nickel |
373 g/L 22.2 g/L 919 g/L 91.1 g/L 9.52 g/L |
50-200 g/L Secondary Drinking Water Standard 2,000 g/L MCL5 300 g/L Secondary Drinking Water Standard 50 g/L Secondary Drinking Water Standard 100 g/L MCL |
| Groundwater (metals concentrations were all above background concentrations) |
Carbon disulfide Chloroform Methylene chloride Bis(2-Ethylhexyl)phthalate Nitroglycerine 2,4-Dinitrotoluene 2-Amino-4,6-DNT 2-Amino-2,6-DNT Nitrobenzene Aluminum Barium Chromium Cobalt Copper Iron Manganese Nickel Vanadium Zinc Mercury Lead Selenium Arsenic |
0.63 g/L 0.8 g/L 2.9 g/L 100 g/L 108 g/L 0.43 g/L 3.72 g/L 1.65 g/L 0.81 g/L 26,200 g/L 350 g/L 410 g/L 84 g/L 117 g/L 21,200 g/L 224 g/L 72.7 g/L 144 g/L 174 g/L 7.74 g/L 310 g/L 11.3 g/L 9.49 g/L |
1,000 g/L RMEGchild 100 g/L MCLproposed 5 g/L MCL 6 g/L MCL; 200 g/L RMEGchild 5 g/L LTHA6 100 g/L CLTHA7 Not available Not available 5 g/L RMEGchild 50-200 g/L Secondary drinking water standard 2,000 g/L MCL; 700 g/L RMEGchild 100 g/L MCL Not available 1,300 g/L MCL 300 g/L CLTHA 50 g/L CLTHA 100 g/L MCL 30 g/L intEMEGchild; 100 g/L intEMEGadult8 5,000 g/L CLTHA 2 g/L MCL 15 g/L EPA action level 50 g/L MCL 50 g/L MCL |
In this section we evaluated the possible pathways for exposure to contamination at Lone Star. We examined these possible exposure pathways to determine whether people in the community can be exposed to (or come into contact with) contaminants from the site. Exposure pathways consist of five elements; 1) a source of contamination, 2) transport through an environmental medium, 3) a point of exposure, 4) a plausible manner (route) for the contaminant to get into the body, and 5) an identifiable exposed population. Exposure pathways can be completed, potential, or eliminated. For a person to be exposed to a contaminant, the exposure pathway must be complete. An exposure pathway is considered complete when all five elements in the pathway are present and exposure has occurred, is occurring, or will plausibly occur in the future. A potential pathway is missing at least one of the five elements but may possibly be completed in the future as more data become available or site conditions change. Eliminated pathways are missing one or more of the five elements and will never be completed. Table 3 summarizes the exposure pathways considered in our evaluation of this site.
No Public Health Hazard Situations
As a result of our site visit observations, and a review of the available data, we concluded that there are no plausible exposure situations associated with the ODA that could pose a public health hazard at this time. Although chemical contaminants have been found on site in surface water, groundwater, sediment, soil, and source material, the current or likely future potential for the public to be exposed to site contaminants at levels which would present a threat to public health is low. An evaluation of each of the pathways that were considered in this assessment is presented below.
Evaluation of Possible Sediment Exposure Pathways
Based on available information, sediment from the drainage area south of the ODA does not present a hazard to public health. Contaminants were reported below detection limits, below levels of health concern or at concentrations similar to background.
Two sediment samples were collected from one location south of the ODA in May and August of 1996. This drainage carries surface water from the area south of the ODA to the East Fork of Elliott Creek. Samples collected from surface sediment (0 feet) and subsurface sediment (0.5 feet), were analyzed for volatile organic compounds, semivolatile organic compounds, explosives, and metals (Table 1).
With the exception of the detection of acetone at a concentration of 0.22 mg/kg in one 0.5 foot sample, volatile organic compounds were reported to be below their respective detection limits. Semivolatile organic compounds and explosive constituents also were reported to be below their respective detection limits. In general, concentrations of metals in the sediment were low with the exception of aluminum and iron; however, these elements are abundant in the earth's crust (Table 2). For instance natural concentrations of aluminum range from about 700 mg/kg to over 100,000 mg/kg [5].
Table 3. Health Hazard Situation - Lone Star Army Ammunition Plant
| PATHWAY NAME |
PRIMARY CONTAMINANTS OF CONCERN |
E X P O S U R E P A T H W A Y S E L E M E N T S | TIME | COMMENTS | ||||
| SOURCE | ENVIRONMENTAL MEDIA |
POINT OF EXPOSURE |
ROUTE OF EXPOSURE |
EXPOSED POPULATION |
||||
| Sediment | Volatile and semivolatile organic compounds, and explosives* were reported at concentrations below their respective detection limits. Metals reported at low concentrations, similar to background levels. | Old Demolition Area | Sediment | Drainage area south of the Old Demolition Area | Dermal Contact | Trespassers On-site workers |
Past Present Future |
Based on available information, sediment does not present a public health hazard. |
| Soil | Explosives* Metals |
Various site activities/ ODA |
Soil | On-site soil | Ingestion Dermal Contact |
Trespassers On-site workers |
Past Present Future |
Based on available information, soil at the ODA does not pose a public health hazard. |
|
Ordnance debris |
Explosives* Metals |
Lone Star Operations/ODA | Debris | On-site | Ingestion | Trespassers On-site workers |
Past Present Future |
No apparent public health hazard since access to this area is restricted and workers working in this area should be adequately trained and protected. |
| Surface Water | Volatile and semivolatile organic compounds and explosives* were reported at concentrations below their respective detection limits. Metals reported at low concentrations, below levels of health concern. | Old Demolition Area | Surface Water | Surface water from drainage area south of the Old Demolition Area | Dermal Contact | Trespassers On-site workers |
Past Present Future |
Based on available information, surface water does not present a public health hazard. |
| Groundwater | The explosive nitroglycerine, the volatile organic compound bis(2-ethylhexyl)phthalate, Metals |
Lone Star Operations | Groundwater | Residential drinking/ showering water |
Incidental Ingestion, Inhalation, Dermal Contact | Local area residents using groundwater for domestic purposes | Future | No public health hazard since contaminants have not migrated towards public water supply wells and the groundwater below the site is not used for drinking or other domestic purposes. |
Evaluation of Possible Soil Exposure Pathways
Based on available information, soil from the ODA does not present a hazard to public health. Contaminants were reported below detection limits, below levels of health concern or at concentrations similar to background concentrations reported in the literature.
During the Phase IV Remedial Investigation, the nature and extent of chemical contamination in surface soil was defined by 50 surface soil samples; 42 composite surface soil (0-6 inches) samples and eight surface soil samples from hand auger borings. Each composite surface soil sample was collected by combining soil from four randomly selected locations within a one-acre area. Sampling locations within each one-acre area were selected by generating random number pairs for x and y coordinates in one-foot increments. Samples were analyzed for explosives and metals. Nitroglycerine, tetryl, and 2,4,6-trinitrotoluene (TNT) were the only explosive compounds detected (Table 2). Nitroglycerine was detected in six of the 50 samples with concentrations ranging from 6.7 mg/kg to 230 mg/kg. Tetryl was detected in three of 12 samples at concentrations ranging from 1.95 mg/kg to 6.06 mg/kg. TNT was detected only in one of 12 samples. Contaminated soil at this location does not represent a hazard to the public since public access to this area is not permitted and institutional restrictions such as fences, signs, locked and guarded entrances maintain this restriction. State and federal regulations require that remedial workers be adequately protected and trained in the hazards of working with contaminated soil so that remedial activities on the site will not present an unreasonable hazard. Additionally, the levels of these contaminants detected in the ODA do not currently represent a health hazard from the type of incidental dermal contact or dust inhalation/ingestion that remedial workers might experience. Metals were reported at concentrations below levels of concern (Table 2).
Evaluation of Possible Source Material Exposure Pathways
Based on available information, at present, the contaminants found in the ordnance debris at this site do not present a hazard to public health since access to the site is restricted and remedial workers should be adequately protected and trained in the hazards associated with the debris. In the future, if access to the site changes, the potential public health hazards associated with contaminants in the ordnance debris, should it remain on the site, should be reevaluated.
During the Phase IV Remedial Investigation four source material samples were collected in the ODA and analyzed for explosives and metals [2]. Source material was collected primarily to characterize the types of chemicals that would be expected to be present in the ODA. To collect the source material, four sparsely vegetated one-acre areas were selected. Within each area, four random locations were chosen using the x and y coordinate procedure described above. At each sample location, an area with a five-foot radius was examined for ordnance debris. A sample of the collected material from each area was analyzed for metals and explosives. Tetryl was detected in all four of the composite debris samples at concentrations ranging from 15.9 to 17.8 percent (by weight). 2,4,6-Trinitrotoluene was detected only in one of the four composite debris samples at 8.05 percent (by weight). Various metals such as lead (6,290 mg/kg), thallium (30 mg/kg), arsenic (31 mg/kg), manganese (4,360 mg/kg) and zinc (223,000 mg/kg) also were found at elevated levels in the ordnance debris (Table 2). Although several of the contaminants were reported at concentrations above health assessment comparison values, the ordnance debris is not likely to present a public health hazard to the community since access to this area is restricted. If the ordnance debris were not removed and access to the site was not restricted, the ordnance debris could present a public health hazard if children were tempted to play with and/or collect it. Remedial workers should be adequately protected and trained in the hazards of the ordnance debris so that remedial activities on the site will not present an unreasonable hazard.
Evaluation of Possible Surface Water Exposure Pathways
Based on available information surface water from the drainage area south of the ODA, including East Fork Elliott Creek, does not present a hazard to public health. Contaminants were reported below detection limits, below levels of health concern or at concentrations similar to background.
The Lone Star facility is situated on a ridge, causing drainage to the north and to the south but the easternmost edge drains eastward and the westernmost edge drains westward. The ODA is within the south-central part of the Lone Star facility. Elevations range from 334 feet above mean sea level along the west-central side of the ODA to 312 feet above mean sea level at the east-central side. The average slope is to the south-southeast at about 3 percent [2]. Contamination of surface water is a potential concern at Lone Star because water runoff from the site and/or transport of contaminants from other contaminated areas to surface water may be possible. The surface water bodies which may receive drainage from Lone Star include East Fork Elliott Creek and Lake Wright Patman.
Surface water in the ODA, originating from rainfall, storm water runoff, and from a seep on the southwest part of the site, collects along two intermittent drainages on the site; one to the south and one to the east. The east drainage discharges into the south drainage which continues for about 1,500 feet before joining with East Fork Elliott Creek.
Although water flow in East Fork Elliott Creek is now year-round due to discharge from Lone Star's wastewater treatment plant, possible migration of contaminants via surface water to the Creek would be infrequent. Surface water flows to the Creek through the south and east drainages or overland only during, or immediately following, a rainfall of greater than 0.6 inches per day (which occurs less than 30 days per year). During dry periods the extent of surface water is limited to stagnant pools in the south drainage/seep area. These pools are sustained by groundwater discharge [2].
During the Phase IV Remedial Investigation, surface water samples were collected from one location in the south drainage way of the ODA. Samples were collected on May 1, 1996 and August 16, 1996. Two samples collected from one location were analyzed for volatile organic compounds, explosives, and metals. Another sample, collected from the same location, was analyzed for semivolatile organic compounds. All volatile organic compounds, semivolatile organic compounds, and explosives were reported to be below their respective detection limits. Metals were reported at concentrations either below detection limits or below levels of concern (Table 2). Iron and aluminum were detected at concentrations above their respective secondary drinking water standards. These standards were established to control the aesthetic qualities of water and are not health based. Exceeding these secondary drinking water standards by the amounts observed at this site could affect the public's acceptance of the water but would not be expected to present a public health hazard even if people were using the water.
Evaluation of Possible Groundwater Exposure Pathways
Based on available data, the public water supplies in the vicinity of Lone Star currently do not contain contaminants associated with the site. Thus, off-site groundwater does not present a public health hazard. Contaminated shallow groundwater beneath the ODA currently does not present a public health hazard since it is not used for potable purposes. If additional on-site groundwater development is included in future use plans, it would be prudent to determine the suitability of the water for the proposed uses.
General Hydrogeology and Public Water Supply Wells
The hydrogeologic system associated with Lone Star is the Wilcox Group. This is the water-bearing zone under the ODA [2]. The Wilcox Group consists of sand units, silts, clays and lignites. Water transmissive units in the Wilcox Group are discontinuous both vertically and laterally; therefore, the water-bearing zones in the Wilcox cannot be classified as a single, homogeneous water-bearing zone. Groundwater, confined in some areas, and unconfined in others, flows south to southeast. The ODA receives very little groundwater flow from other areas of Lone Star.
In an earlier remedial investigation [3], approximately 200 water wells were identified within 2 miles of the Lone Star boundary. The report states that most are privately owned wells used for domestic supply and most are deep aquifer wells installed below the Midway Group to depths of 500 to 800 feet. Shallow wells are generally in alluvial soils near the Red River; and in fact, wells near the northeast corner of Lone Star were installed in Red River alluvial terrace deposits overlying the Midway group. Unlike the deeper wells that are isolated from shallow groundwater, these shallow domestic wells could potentially be influenced by shallow groundwater. There are several RCRA regulated sites in the northern half of Lone Star. The potential for contaminants to migrate to off-site wells from these RCRA sites is low.
Lone Star purchases drinking water from the City of Texarkana; the source of this water is primarily Lake Wright Patman. Small public water supplies in the vicinity of Lone Star include the City of Redwater and the City of Maud and mobile home parks. The closest public water supply wells are greater than one mile southeast of the ODA. These two wells, which supply water to approximately 90 people living in Cody's Mobile Home Park, are 42 and 44 feet deep, drilled in the Midway group. Based on available data, the public water supplies in the vicinity of Lone Star currently do not contain contaminants associated with the site.
On-site Old Demolition Area Monitoring Wells
A total of 18 wells were installed at the ODA at Lone Star; the wells range in depth from approximately eight to 44 feet. During the Phase IV Remedial Investigation, 38 shallow groundwater samples collected from these monitoring wells were analyzed for explosives. Ten groundwater samples collected from four of the monitoring wells were analyzed for volatile organic compounds. Fifty-six groundwater samples were collected from 13 monitoring wells and analyzed for metals; 28 of the samples were unfiltered and 28 were filtered with metal concentrations reported as dissolved. Maximum reported concentrations were obtained from the unfiltered samples (Table 2).
Volatile organic compounds, semivolatile organic compounds, and explosives were detected in the groundwater samples below levels of public health concern. Nitroglycerine was detected at a maximum concentration of 108 g/L, a concentration greater than the recommended lifetime health advisory concentration for this contaminant. The maximum concentrations of aluminum, iron, and manganese detected in the groundwater were greater than background concentrations and greater than EPA's secondary drinking water standards for these contaminants; however, these standards are set for aesthetic reasons and are not necessarily health based. Manganese is an essential dietary nutrient; the World Health Organization (WHO) has estimated the average dietary intake of manganese to range from approximately 2,000 to 8,800 micrograms per day. The Food and Nutrition Board of the National Research Council has established "estimated safe and adequate daily dietary intake levels" for this nutrient that range from 300 micrograms per day for infants to 5,000 micrograms per day for adults. The WHO has concluded that 8,000 to 9,000 micrograms per day is "perfectly safe" for adults. We would not anticipate the levels of manganese in the water to pose a threat to public health; particularly since the water is not used for potable purposes.
Vanadium was detected in nine of the 28 unfiltered groundwater samples at concentrations ranging from 9.46 micrograms per liter to 144 micrograms per liter. The maximum detected value (144 micrograms per liter) exceeds the health based screening value for this contaminant derived using ATSDR's intermediate oral minimal risk level (MRL). Assuming a 70 kg adult consumption of 2 liters per day, the maximum concentration of 144 g/L is equivalent to a daily dose of 0.004 milligrams vanadium per kilogram body weight (0.004 mg/kg/day). The MRL for this contaminant (0.003 mg/kg/day) is based on a study in which selected concentrations of vanadium were administered to rats in their drinking water for three months. The animals showed mild histological changes in kidneys, lungs, and spleen that become progressively more severe with increased dosages. A No Observable Adverse Effects Level (NOAEL) was identified and used to establish the MRL for humans. To establish the MRL the NOAEL was divided by an uncertainty factor of 100 (10 for extrapolation from animals to humans, and 10 for human variability). Vanadium only was detected in 25% of the samples; most of the samples had reported concentrations below the health based screening level. Although the maximum concentration of vanadium detected in the groundwater exceeded the health based screening level, we would not expect the vanadium in this water to result in observable adverse health effects. Additionally, this water is not currently being used for drinking or other domestic purposes. The maximum concentration of lead detected in the groundwater (310 g/L) exceeded background concentrations of lead in groundwater and the EPA action level for this contaminant (15 g/L). If this water were regularly consumed by children the presence of lead in the water could pose a health threat. Since this water is not currently being used for drinking or other domestic purposes, the lead and other constituents in the groundwater currently do not present a public health hazard.
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