Water Modeling (FAQs)
1. What is Water Modeling? Why Does ATSDR Need It?
ATSDR needs certain information about the volatile organic compounds (VOCs) in Camp Lejeune's groundwater and drinking water. Little data exists about how chemicals have affected the base's water in the past. Water modeling is a scientific method that will help ATSDR estimate water-system conditions prior to March 1987. Water modeling will help identify where and when certain areas at Camp Lejeune received VOC-contaminated drinking water. ATSDR will use the water modeling results to determine which people were exposed to contaminated drinking water.
2. How many water treatment systems served the base?/ What water systems on base were contaminated?
Eight water treatment plants provided drinking water to family housing units and barracks at the base prior to March 1987: Tarawa Terrace, Hadnot Point, Holcomb Boulevard, Courthouse Bay, Rifle Range, Onslow Beach, Montford Point/Camp Johnson and New River.
Specific volatile organic compounds (VOCs) were first detected in finished water at the Hadnot Point and Tarawa Terrace drinking water treatment plants in 1982. In 1984, water supply wells at Tarawa Terrace and Hadnot Point were sampled and specific VOCs were detected. The modeling of the Tarawa Terrace drinking water system estimated that the system was contaminated with tetrachloroethylene (also known as perchloroethylene or “PCE”) from Nov. 1957-February 1987 at levels above the current maximum contaminant level of 5 micrograms per liter (μg/L). (Note: 1 μg/L of a drinking water contaminant is equivalent to 1 part per billion or ppb.) The highly contaminated wells were shut down in February 1985, and the system itself was shut down in March 1987.
The Holcomb Boulevard drinking water treatment plant began operation in June 1972 and was generally not contaminated with solvents. However, during the dry months in late spring or early summer, the Holcomb Boulevard system occasionally required additional water from the contaminated Hadnot Point system to meet demand. On January 27, 1985, the Holcomb Boulevard system was shut down for repairs until February 7, 1985. During this time, contaminated water from Hadnot Point supplied water to the family housing units in the Holcomb Boulevard system.
The Hadnot Point drinking water system is still being modeled. We know that trichloroethylene (TCE) was found at 1400 μg/L and trans 1,2-dichloroethylene (DCE) was found at 407 μg/L in the finished water at the treatment plant. Vinyl chloride was found at 655 μg/L in one Hadnot Point supply well, and benzene was found at 720 μg/L in another Hadnot Point supply well. Based on sample data, the Hadnot Point system has been free of VOC contamination since 1987.
Below is information on the housing areas on base and which water systems provided their water:
- Tarawa Terrace - served by Tarawa Terrace drinking water system
- Knox Trailer Park - served by Tarawa Terrace and Montford Point/Camp Johnson drinking water systems
- Berkeley Manor, Midway Park, Paradise point - Prior to June 1972, served by Hadnot Point drinking water system
- Berkeley Manor, Midway Park, Paradise Point, Watkins Village - from June 1972 onward, served by Holcomb Boulevard drinking water system, except for occasional periods during dry spring/summer months when supplemental water came from Hadnot Point, and a two-week period in January-February l985 when the Holcomb Boulevard system was down for repairs and Hadnot Point water supplied these units
- Hospital Point - served by Hadnot Point drinking water system
- Barracks/Most Bachelor's quarters - served by Hadnot Point drinking water system
- Courthouse Bay, New River, Camp Geiger, Camp Johnson, Rifle Range - served by drinking water systems not contaminated with solvents
3. When was the drinking water contamination discovered?
Specific volatile organic compounds (VOCs) were detected in finished water at the Hadnot Point and Tarawa Terrace treatment plants in 1982. The samples were collected by Camp Lejeune staff. Finished water at Tarawa Terrace was contaminated with tetrachloroethylene (also known as perchloroethylene or “PCE”). The maximum level of PCE found in the finished water at Tarawa Terrace was 215 μg/L. The source of the contamination was an off-base dry cleaners. Over time, PCE in ground water degrades into trichloroethylene (TCE), trans 1,2-dichloroethylene (DCE) and vinyl chloride. In the Tarawa Terrace system, TCE (8 μg/L) and DCE (12 μg/L) were detected.
In the finished water at the Hadnot Point treatment plant, TCE levels as high as 1,400 μg/L were found. Other contaminants detected in Hadnot Point finished water included PCE (15 μg/L), DCE (407 μg/L) and vinyl chloride (3 μg/L). In one Hadnot Point supply well, benzene levels as high as 720 μg/L were detected. In another Hadnot Point supply well, vinyl chloride levels as high as 655 μg/L were detected.
Other on-base treatment plants were not contaminated.
4. Was the Holcomb Boulevard treatment plant contaminated?
Holcomb Boulevard wells were generally not contaminated with solvents. However, contaminated water from Hadnot Point supplied the Holcomb Boulevard system when the Holcomb Boulevard plant was shut down for almost two weeks during January 27-Febraury 7, 1985. In addition, contaminated water from Hadnot Point was used on occasion to supplement the Holcomb Boulevard supply during dry spring and summer months.
5. Do the ATSDR studies and the water modeling effort take into account the benzene information?
The studies and the water modeling take into account the benzene information. The studies and the water modeling also include information on other contaminants (TCE, PCE, DCE, vinyl chloride) found in the Hadnot Point drinking water system.
One supply well serving the Hadnot Point drinking water system was highly contaminated with benzene. This well, “#602”, was sampled in July 1984 and found to have 380 per billion (μg/L) of benzene. The current drinking water standard for benzene is 5 μg/L. Well #602 was in operation during the July 1984 sample. However about 20 other wells that were not contaminated with benzene were also operating at the time. Water from all these wells was mixed together at the treatment plant before entering the drinking water system. Therefore, the level of benzene in the drinking water system would be much less than the level detected in well #602. Well #602 was placed out of service in late November 1984. Benzene was detected at 120 μg/L and 720 μg/L in two samples taken soon after the well was placed out of service.
ATSDR is currently modeling the Hadnot Point drinking water system to estimate the monthly average levels of benzene and the other contaminants in the drinking water system.