Sewage treatment plant
Another area of the base that is being examined is where a sewage treatment plant operated from 1953 to 1978. A chemical called dieldrin was found in the surface soil, arsenic was found in the ground water, and PCB in surface water. Contaminated soil was excavated, but then additional petroleum and solvents were detected. “They encountered more contamination than they estimated,” said Keating. “They’re doing additional sampling there.”
Three closed landfills
The West Gate Landfill was capped in the summer of 2011, and the so-called “Small Landfill” was capped in summer 2010. PCB-impacted soil was removed from the “Rubble Disposal Area,” which was covered with a vegetated soil cap.
Firefighter training areas
At one time, 500 to 1,500 gallons of fuel per month were burned during firefighting exercises at the base. Petroleum-soaked soils were removed from the site. Chemicals found in firefighting foam have been detected in the ground water.
Tile leach field
This area is about a third of an acre, adjacent to French Stream, that was used for disposal of sanitary wastes from 1945 to the early 1950s. Studies of the soil and ground water found that risks did not exceed regulatory thresholds. In May 2006 the EPA and the Navy concluded that no further action was necessary at the site.
The so-called “Abandoned Bladder Tank Fuel Storage Area” is where four 10,000-gallon tanks that were used to store aviation gasoline were removed in 1987.
Industrial operations area
This encompasses the power plant, maintenance facilities, building shops, and water tower in the central area of the base. The Navy has sampled the soil and found no ground-water issues. Several places need to be excavated because PCBs were found, and planning is underway to remove soil.
This hangar is located near the center of the base. It was built in 1956 and used as an aircraft storage and maintenance facility. Elevated trichloroethylene (TCE) concentrations in ground water were detected to the south and southeast of the site. (TCE is an industrial solvent used to degrease machinery and has been linked to higher risks of Parkinson’s disease and certain cancers.) The cleanup plan includes chemical oxidation and injection of a material into the ground to enhance the biodegradation of volatile organic compounds. EPA officials estimate that the site will be clean in five to seven years.
The Marine Air Reserve Training Building is gone, and all that is left is a concrete slab. A feasibility study is being finalized and a proposed cleanup plan should be ready for public review this summer.
A public meeting on Building 81 is expected to take place in July.
The next Restoration Advisory Board meeting is scheduled for May 9 at 7 p.m. at the New England Wildlife Center at 500 Columbian St. in Weymouth.