Contaminated Water Supplies at Camp Lejeune Assessing Potential Health Effects (2009) / Chapter Skim
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2 Exposure to Contaminants in Water Supplies at Camp Lejeune
2 Exposure to Contaminants in Water Supplies at Camp Lejeune
Pages 28-66
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From page 28... ...
. Then, an overview of the water-supply contamination scenarios at Camp Lejeune and important considerations for characterizing them are presented, including hydrogeologic features of the site, the base's water-treatment plants and distribution systems, contaminated areas, and water-quality measurements.
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From page 29... ...
Marine Corps constructed a water-distribution piping system at Camp Lejeune. The source of water in the system was, and continues to be, groundwater wells.
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From page 30... ...
Those wells directly serve the Holcomb Boulevard, Marine Corps Air Station, Courthouse Bay, Camp Johnson, Camp Geiger, and Rifle Range water-supply systems and several smaller systems. Some water-supply systems are connected (for example, Holcomb Boulevard and Hadnot Point)
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From page 31... ...
The aquifers include the Castle Hayne aquifer and two other deep aquifers beneath the Beaufort confining unit, the Beaufort and Peedee aquifers. All the water-supply wells were installed within the Castle Hayne aquifer, so site characterization efforts focused on understanding the hydrostratigraphy of the upper three hydrogeologic units: the surficial aquifer, the Castle Hayne confining unit, and the Castle Hayne aquifer.
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From page 32... ...
32 FIGURE 2-2 Geologic cross section of Camp Lejeune. Source: Harden et al.
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From page 33... ...
The bottom of the Castle Hayne aquifer is bounded by a regionally continuous clay unit, which is designated the Beaufort confining unit. All the groundwater-extraction wells in the base are in the Castle Hayne aquifer.
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From page 34... ...
At various times, four systems have been the primary sources of water for residences other than barracks at Camp Lejeune since the first system was put into service: Hadnot Point, Tarawa Terrace, Marine Corps Air Station, and Holcomb Boulevard. Several smaller systems have supplied or still supply other areas of the base that have relatively low populations.
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From page 35... ...
TABLE 2-1 Water Supply of Housing Areas, Camp Lejeune, North Carolina (1941-2000) Housing Area Water-Treatment Plant Dates of Service Family housing areas Courthouse Bay Courthouse Bay 1942-2000 Berkeley Manor Hadnot Point 1961-1971 Holcomb Boulevard 1972-2000 Hospital Point Hadnot Point 1947-2000 Knox Trailer Park Tarawa Terrace 1952-1986 Holcomb Boulevard 1987-2000 Knox Trailer Park Expanded Holcomb Boulevard 1989-2000 Marine Corps Air Station Marine Corps Air Station 1958-2000 Midway Park Hadnot Point 1943-1971 Holcomb Boulevard 1972-2000 Paradise Point Cape Cod Hadnot Point 1948-1971 Holcomb Boulevard 1972-2000 Paradise Point Capehart Hadnot Point 1962-1971 Holcomb Boulevard 1972-2000 Paradise Point Cracker Box Hadnot Point 1947-1971 Holcomb Boulevard 1972-2000 Paradise Point general officer housing Hadnot Point 1943-1971 Holcomb Boulevard 1972-2000 Paradise Point two-story housing Hadnot Point 1943-1971 Holcomb Boulevard 1972-2000 Rifle Range housing Rifle Range 1942-1993 Onslow County 1994-2000 Tarawa Terrace I and II Tarawa Terrace 1952-1986 Holcomb Boulevard 1987-2000 Watkins Village Holcomb Boulevard 1978-2000 Barracks subcamps (not individual barracks)
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From page 36... ...
(1) The drinking water at Camp Lejeune is obtained from groundwater pumped from a freshwater aquifer located approximately 180 ft below the ground.
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From page 37... ...
VOCs (M) Camp Johnson 2 None Abbreviations: BTEX = benzene, toluene, ethylene, and xylene; D = deeper wells in Castle Hayne aquifer, source of water-supply wells; M = shallow wells, surficial aquifer, or soil vadose zone.
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From page 38... ...
. During August 1982, a routine analysis with gas chromatography-mass spectrometry (to screen the water samples collected from the Tarawa Terrace water-treatment plant for chlorination byproducts)
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From page 39... ...
Measurements of mixed water samples suggest that supply wells TT-23 and TT-26 were major contributors to contamination of the Tarawa Terrace water supply. ATSDR (Faye and Green 2007)
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From page 40... ...
40 Contaminated Water Supplies at Camp Lejeune -- Assessing Potential Health Effects TABLE 2-3 Observed Concentrations of PCE in Tarawa Terrace Water-Supply Wells Sample Date PCE, µg/L Detection Limit, μg/L Supply well TT-23 Jan.
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From page 41... ...
TT-2453 July 28, 1982 104 -- -- Unknown TTWTP Bldg. TT-38 July 28, 1982 76 -- -- Unknown TTWTP Bldg.
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From page 42... ...
also summarized analytic results for benzene and toluene in finishedwater samples collected at the Tarawa Terrace water-treatment plant in 1985 (see Table 2-5)
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From page 43... ...
The permeable Castle Hayne aquifer formation, where all the water-supply wells are, is assumed to be below that confining layer. In the model, the Castle Hayne aquifer formation is divided into five distinct units.
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From page 44... ...
16-56 1 Local confining unit 7-17 2 Upper Castle Hayne aquifer-lower unit 8-30 3 Middle Castle Hayne aquifer confining unit 12-28 4 Middle Castle Hayne aquifer 32-90 5 Lower Castle Hayne aquifer confining unit 18-30 6 Lower Castle Hayne aquifer 41-64 7 Beaufort confining layer Bottom boundary N/A Source: Modified from Faye and Valenzuela 2007. ATSDR calibrated the MODFLOW and MT3DMS models for Tarawa Terrace by using a "hierarchical process" that included the simulation of the following four successive scenarios: (1)
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From page 45... ...
and Chapter C (Faye and Valenzuela 2007) reports for geohydrologic framework corresponding to appropriate model layers; aquifers are model layers 1, 3, 5, and 7; confining units are model layers 2, 4, and 6.
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From page 46... ...
Marine Corps Base Camp Lejeune, North Carolina. Source: Maslia et al.
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From page 47... ...
Exposure to Contaminants in Water Supplies at Camp Lejeune 47 TABLE 2-8 Simulated and Observed PCE Concentrations at Water-Supply Wells and Calibration Target Range, Tarawa Terrace and Vicinity PCE Concentration, µg/L Site Date Observed Simulated Calibrated Target Range, µg/L RW1 July 12, 1991 ND 0.0 0.0-2.0 RW2 July 12, 1991 760 1,804 240-2,403 RW3 July 12, 1991 ND 0.0 0.0-2.0 TT-23 Jan.
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From page 48... ...
Therefore, the predicted concentrations of TCE, trans1,2-DCE, and vinyl chloride in the Castle Haynes aquifer at the location of intake by Tarawa Terrace supply wells should be used with considerable caution. Gaps in and Limitations of the Modeling The committee reviewed the Tarawa Terrace modeling reports and found that ATSDR applied the public-domain codes for MODFLOW and MT3DMS and two cutting-edge research codes PsOps and TechFlowMP to model the complex groundwater-contamination scenario at Tarawa Terrace.
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From page 49... ...
and encouraging former Camp Lejeune marines and their families to find the estimated exposure concentrations of these contaminants leads to a misleading perception that reactive transport models can make accurate predictions. In the absence of data, historical reconstruction efforts that use groundwater models can only provide a general conceptual framework for what happened at the site and why.
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From page 50... ...
In July 1972, the Holcomb Boulevard water system took over supplying water to some areas originally served by the Hadnot Point system. The two systems were connected, such that on several occasions the Hadnot Point system temporarily served or supplemented the Holcomb Boulevard system.
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From page 51... ...
The Navy initially identified 13 sites as potential sources of contaminants of the Castle Hayne aquifer in the Hadnot Point area (Baker Environmental, Inc 1999)
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From page 52... ...
contaminated with chlorinated connected to site 6 solvents OU 7, site 1 French Creek liquids disposal Shallow groundwater contaminated with petroleum products, area chlorinated solvents OU 7, site 28 Hadnot Point burn dump Surface soils contaminated with volatile, semivolatile compounds Shallow groundwater contaminated with metals OU 7, site 30 Sneads Ferry Road fuel tank Soil contaminated with VOCs sludge area OU 15, site 88 Building 25, base dry cleaners Soil, shallow groundwater contaminated with solvents OU 18, site 94 Former PCX service station Groundwater contaminated with petroleum hydrocarbons, chlorinated solvents Pre-RI 10 Original base dump No significant contamination of soil or groundwater identified Pre-RI 12 Explosive ordnance disposal No significant contamination of soil or groundwater identified area Abbreviation: RI = remedial investigation. Site 28 is a former 23-acre burn dump, operated from 1946 to 1971, south of the Hadnot Point industrial area (Baker Environmental, Inc 1995)
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From page 53... ...
Exposure to Contaminants in Water Supplies at Camp Lejeune 53 FIGURE 2-6 Designated hazardous-waste remedial investigation sites at Hadnot Point.
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From page 54... ...
Of the nine analytes, the most prevalent compounds in mixed water samples collected from various locations in the Hadnot Point water-treatment plant and distribution system with measurable concentrations were TCE (31 quantified samples had a mean of 399 μg/L and a range of 1-1,400 μg/L) and trans-1,2-DCE (21 quantified samples had a mean of 169 μg/L and a range of 2-407 μg/L)
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From page 55... ...
. Hadnot Point Supply-Well Operation and Implications The supply wells for the Camp Lejeune water system were on a cycled pumping schedule; that is, generally only some of the wells were pumping raw water to the water-treatment plant at any given time (GAO 2007)
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From page 56... ...
See Table 2-12 for additional information about these samples. d Concentrations measured in seven of 11 samples collected before 1984 were assumed to be detected on basis of notes on laboratory reports and inferences from later laboratory reports.
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From page 57... ...
b Concentrations measured in seven of 11 samples taken before 1984 assumed to be detected on basis of notes on laboratory reports and inferences from later laboratory reports. Abbreviations: DCE = dichloroethylene; MC = methylene chloride; ND = not detected; NQ = not quantified; TCA = trichloroethane; VC = vinyl chloride.
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From page 58... ...
Abbreviations: DCE = dichloroethylene; IR = installation restoration; MC, methylene chloride; ND = not detected; PCE = perchloroethylene; TCE = trichloroethylene; VC = vinyl chloride.
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From page 59... ...
f Contaminant not measured or reported for mixed water samples collected on this date. Abbreviations: DCE = dichloroethylene; MC = methylene chloride; PCE = perchloroethylene; TCE = trichloroethylene.
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From page 60... ...
Thus, the analytic results on water samples taken from deep monitoring wells should be representative of contamination of the Castle Hayne aquifer at a depth consistent with water withdrawal from the water supply, albeit at least 7 years after the discovery of contaminants in the Hadnot Point supply wells. The remedial investigation of site 78 was preceded by several investigations, including an initial assessment study (1983)
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From page 61... ...
. Some specific information on the Camp Lejeune population is being sought as part of ATSDR's case-control study focused on birth defects and childhood cancer outcomes (see Chapter 8)
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From page 62... ...
AFFECTED STUDY POPULATION Residential history in housing areas served by the contaminated water supplies during the period of contamination is an important determinant of exposure. There are two major categories of housing at Camp Lejeune: family housing for personnel on assignment to Camp Lejeune and barracks for enlisted personnel rotating through the base for training.
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From page 63... ...
during the study period other than the 2-week period in winter 1985 when the Holcomb Boulevard system received contaminated water from the Hadnot Point TABLE 2-15 Potential Sites of Nonresidential Exposure to Contaminants in the Tarawa Terrace and Hadnot Point Water Systems, 1943-1985 Exposure Scenario Years Contaminated Employment at Hadnot industrial area or other workplace Unknown-1985 Employment location served by Tarawa Terrace water system 1957-1985 Tarawa Terrace Elementary School 1957-1985 Tarawa Terrace day care 1957-1985 Hadnot Point-Holcomb Boulevard area schools Until 1972; intermittent linkages with the Hadnot Russell School, 1943-1987 Point system; and during a 2-week period in 1985 Old high school/middle school, 1963-1987 Berkeley Manor Elementary School, 1963-present Stone Street Elementary School, 1959-present Midway Park Elementary School, 1952-present Hadnot Point-Holcomb Boulevard area day-care services Until 1972; intermittent linkages with the Hadnot New hospital, 1983-1987 Point system after 1972; and during a 2-week period Building 712, 1966-1982 in 1985 Building LCH4025, 1960-1987 Building 799, 1953-1987 Building 2600, unknown-1987 Building 899, 1985-1987 Building 1200, 1942-1987 Source: Marine Corps, personal commun., December 4, 2007.
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From page 64... ...
Given the nature of the contamination at Camp Lejeune, the committee found the application of broad classifications of exposure based on place and duration of residence to be an appropriate approach for assessing exposure in the studies described above. Historical reconstruction and groundwater modeling at Tarawa Terrace have provided additional characterization of potential exposure to PCE and an estimated timeframe for the contamination, but it is questionable whether the additional information improves the exposure assessment for epidemiologic studies.
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From page 65... ...
For example, the extent and characterization of the Castle Hayne confining unit are critical for understanding the potential for hydraulic connectivity between the waste sites identified and the source aquifer for the water-supply wells over the period of potential exposure (1943-present)
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From page 66... ...
, and other information relevant to exposure assessment that relies on environmental samples collected in the course of investigating water, soil, and air quality at Camp Lejeune. Because of the sparseness of water-quality data and the insufficient ability of water-quality modeling to make up for the absence of information, most exposure estimates in epidemiologic studies at Camp Lejeune will rely heavily on unverifiable assumptions and projections.
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