Water Modeling (FAQs)

• What is Water Modeling? Why Does ATSDR Need It?
• How many water treatment systems served the base?/ What water systems on base were contaminated?
• When was the drinking water contamination discovered?
• Was the Holcomb Boulevard treatment plant contaminated?
• Do the ATSDR studies and the water modeling effort take into account the benzene information?

1. What is Water Modeling? Why Does ATSDR Need It?

ASTDR 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.

Volatile organic compounds (VOCs) were detected in Hadnot Point and Tarawa Terrace wells and their water distribution systems during the base's 1980-85 sampling program.

The Tarawa Terrace drinking water system was contaminated with perchloroethylene from Nov. 1957-February 1987 at levels above the current maximum contaminant level of 5 ppb. It was shut down in March 1987, but the heavily contaminated wells were shut down in February 1985.

The Holcomb Boulevard drinking water system was constructed in June 1972 and was generally not contaminated with solvents except for some intermittent exposures. 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 Bridge system.

The Hadnot Point drinking water system is still being modeled. We know that trichloroethylene was found at 1400 ppb, trans 1,2-dichloroethylene was present at more than 300 ppb, and benzene and pesticides were found in the water.

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?

Volatile organic compounds (VOCs) were detected in Hadnot Point and Tarawa Terrace wells during a 1980-85 sampling program. The samples were collected by Camp Lejeune staff. The chemicals detected included tricholorethylene (TCE), perchloroethylene (PCE), benzene, and trans 1,2-dichloroethylene (DCE). Contamination of wells began many years before detection. Other on-base treatment plants were not contaminated. Contamination of Hadnot Point and Tarawa Terrace drinking water systems was intermittent. Wells rotated in and out of service. Each system had more wells than necessary to supply water on any given day.

4. Was the Holcomb Boulevard treatment plant contaminated?

Holcomb Boulevard wells were generally not contaminated with solvents except for some intermittent exposures. 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. Contaminated water from Hadnot Point was used sporadically to supplement the Holcomb Boulevard supply during dry summer months when the golf courses were watered.

5. Do the ATSDR studies and the water modeling effort take into account the benzene information?

The studies and the water modeling include benzene as well as the other contaminants (TCE, PCE, DCE, vinyl chloride) found in the Hadnot Point drinking water system. (Benzene was not detected in the Tarawa Terrace drinking water system.)

One supply well serving the Hadnot Point drinking water system was heavily contaminated with benzene. This well, “#602”, was sampled in July 1984 and found to have 380 per billion (ppb) of benzene. The current drinking water standard for benzene is 5 ppb.

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 ppb and 720 ppb 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.