Contaminated Military Bases:
- Marine Corps Logistics Base Barstow
- El Toro Marine Corps Air Station (decommissioned)
- Mather Air Force Base
- McClellan Air Force Base
- March Air Force Base
- Norton Air Force Base
- Camp Pendleton Marine Corps Base
24 Bases with reported TCE water contamination
(Source: Agency for Toxic Substances and Disease Registry)
Naval Weapons Industrial Reserve Plant
Read more about this article..
The Navy investigated the groundwater beneath the NWIRP Bedford site during several environmental studies: the 1989 Phase I RI, the 1990 Supplemental Investigation, the 1992−1993 Phase II RI, the 1997 Environmental Baseline Study, and the 1998 Supplemental Investigation. Groundwater investigations indicate that groundwater flow from Hartwell’s Hill is largely influenced by topography: groundwater in the till flows outward in all directions from the top of the hill into the more permeable glacial outwash sands at the base of the hill (Halliburton NUS 1992). Once in the flat area at the base of the hill in the northern section, groundwater slowly discharges further northward into the Elm Brook (Roger, Golden, & Halpern 1986). Groundwater contamination in the southern section of the site is believed to be coming from the Hanscom Air Force Base site.
Surveys were undertaken by the Bedford Board of Health and Department of Public Works to determine whether any private drinking water wells were located near the NWIRP Bedford site (Halliburton NUS 1992, 1994). The survey results indicated that 12 residences within 1 mile east and northeast of the site (in the Hartwell Acres neighborhood) had private wells. The closest of the residences is located 700 feet from the northeast property line. All the homes are connected to the town of Bedford’s municipal water supply. Some of the private well owners reported using well water for watering lawns (Roger, Golden, & Halpern 1986). Although we have no way of knowing the full extent to which residents use their private wells, information gathered through the survey indicates that it was unlikely that these private wells have been used for drinking water or other domestic uses. Furthermore, ten of the twelve residences registered average municipal water use. Although two residences had average-to-low or low municipal water use, they are located more than 2,000 feet from the northeast corner of NWIRP Bedford and therefore, are unlikely to be impacted by site contamination (Halliburton NUS 1992, 1994).
BTEX compounds contaminate the groundwater beneath the Transportation and Antennae Range Buildings of the site. The highest concentrations of these contaminants were detected during 1993 Phase II sampling in monitoring well (MW) 18, where total BTEX compounds reached 99,800 parts per billion (ppb). Concentrations of the individual constituents (benzene at 3,000 ppb, ethylbenzene at 7,800 ppb, toluene at 49,000 ppb, and total xylenes at 40,000 ppb) exceeded ATSDR’s CVs for drinking water. Table 8 presents the maximum concentration of BTEX compounds detected at the site. Polycyclic aromatic hydrocarbons (PAHs) such as napthalene (up to 130 ppb) and 2-methylnapthalene (up to 38 ppb)—also constituents of gasoline—were detected in the overburden samples at concentrations above ATSDR’s CV for drinking water. Findings of BTEX and PAHs together provide further evidence that the plume most likely originated from the gasoline release at the former UST. Neither BTEX constituents nor PAHs were measured in samples collected from the bedrock aquifer (Tetra Tech NUS 1999, 2000a).
BTEX is an acronym for benzene, toluene, ethylbenzene, and xylene, a group of volatile organc compounds found in petroleum hydrocarbons such as gasoline. These compounds were found in the groundwater in the northern section of the NWIRP Bedford site l gasoline released from a former UST. BTEX can dissolve in and move in groundwater, but because it sticks to soil particles, it moves slower than groundwater.