|Cleanup Underway at Navy Runway Workshops|
Published: Friday, 03 August 2012 05:29
The 4.18-acre cleanup Site 34 in the Naval Air Station's runway area next to the Oakland Estuary looks barren from a distance. But up close, concrete slabs and pavement remind us of its bygone days as a bustling workshop area.
This area was once part of the division known as the Naval Air Rework Facility (NARF). Everything from sandblasting and painting, to metal working, woodworking and scaffold maintenance went on out there. More than 40 years of activity left soil around buildings contaminated with lead, arsenic, pesticides, PCBs, and aircraft and diesel fuel. Above-ground fuel storage tanks and electrical transformers contributed to the contamination.
The Navy will clean up the soil in this area next year. The draft work plan, which the Navy released July 31, was discussed during a presentation at this month's Restoration Advisory Board (RAB) meeting.
Based on more than 200 soil samples taken both this year and in years prior, the contractor created the draft work plan. Separate groundwater samples indicate contamination from the solvent trichloroethane. No remedial action is being taken on the trichloroethane, however, because vapor intrusion into residences is not a factor, as this land will become Public Trust Land on which housng is not permitted; and water monitoring has shown that the chemical is not migrating toward the estuary.
The northern edge of this site is part of the early westward land extension of Alameda, which allowed trains carrying freight and passengers to reach a point where the water was deep enough for ferry connections; more fill was later added to the area. According to the Navy's Remedial Investigation report, "In the 1920s, most of IR Site 34 was filled with estuary dredging material during construction of the Posey Tube."
By the time the closure of the Navy base was announced in 1993, this workshop area had 12 buildings, seven above-ground storage tanks, two "generator accumulation points" (waste storage), 15 transformers, and more than 7,000 feet of aviation fuel line. Between 1996 and 2000 the Navy removed everything except the concrete pads and pavement.
Building demolition ended shortly after Alameda Point became a Superfund site in July 1999. The Superfund program, officially called the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), does not allow for land improvements such as building demolition.
Most of the soil cleanup locations are adjacent to the exterior edges of old building slabs. Much of the lead in the soil came from sandblasting lead-based paint. Other contamination came from lubricants used for metal fabrications, and the use of oils and solvents for woodwork and metal work.
In addition to removing soil next to the slabs, the contractor will dig under the slabs at the hot spots to take what is called a sidewall sample to confirm that all contaminated soil is removed. The Navy has to keep digging as long as contamination is found; clean soil will be brought in to the areas where soil is removed.
A strip of coastal marshland running along the Oakland Estuary on the north end of the site has no contamination. Its habitat quality, however, is marred by discarded concrete, wood and trash. It will be up to the city to initiate wetlands restoration efforts there.
The 60-day public comment period is underway. The work plan will be finalized in January 2013. Fieldwork is anticipated to take place January through April 2013.
The Navy is scheduled to turn the site over to the city in 2014.
Richard Bangert writes the online Alameda Point Environmental Report about cleanup, open space and wildlife.