The vacated residential area known as North Housing—located between Alameda Point and Alameda Landing—has been deemed environmentally safe for transfer out of Navy hands. The approval comes after a four-year effort to clean up groundwater to drinking water standards was declared unnecessary and terminated.
The original overly cautious risk assumption in the 2007 cleanup plan—that humans might somehow ingest the salty groundwater 10 to 20 feet below the surface—is now seen as implausible. The vapor extraction system covering a six-acre area of benzene and naphthalene-contaminated groundwater was dismantled in 2014 after a new round of tests showed that there is no evidence of harmful vapors rising to the surface.
The land was originally slated for transfer to the Coast Guard. But the Coast Guard decided in 2008 that it no longer wanted the property. The Navy and the city then worked out a plan that incorporates a federal requirement for homeless accommodation and a for-profit development.
The 22.7 acres slated for auction to a private developer will be tagged with utility infrastructure costs—streets, drainage, utilities—on all of the North Housing area, except for the Housing Authority’s 13.6 acres and Habitat for Humanity’s 2.2 acres. The Housing Authority and Habitat for Humanity will be responsible for bringing new utility services from the nearest street to their housing units.
Mosley Avenue will be connected between Alameda Landing and North Housing with 360 feet of new roadway.
In 2013, the Navy turned off its air pump and carbon filter vacuum cleanup system to see if it made any difference in the concentrations or movement of contaminants. It didn’t.
But before the U.S. Environmental Protection Agency (EPA) would sign off on a permanent shutdown of the cleanup system, it wanted a new set of tests at ground level to ensure there is no risk of harmful vapors. The Navy conducted tests inside the vacant housing, in the crawl spaces, and under the parking lot and basketball courts at the former Island High School property. The negative results satisfied the EPA.
In April the Navy officially amended its original 2007 Record of Decision cleanup plan, with regulatory agency concurrence, citing new evidence. It also cited city, county, and state regulations that prohibit intrusive activities and specifically prohibit well installation in the shallow groundwater where the contamination is located. The cleanup plan amendment said that results of the evaluations of extensive data for this cleanup area “show that there is no unacceptable risk for current residential and school uses and any potential future land uses.”
The amended plan also cited new evidence that suggested the contaminants were part of what is called the Marsh Crust at around 20 feet below ground and essentially stuck there. The Marsh Crust is a layer of “hydrocarbon gunk” that Oakland Gas Light Company’s coal gasification plant discharged from about 1880 to 1910. The waste discharges went into what was then San Antonio Creek, and much of it settled on the nearby marshland where North Housing now sits.
The land was never cleaned up before being filled in for use as San Francisco Bay Aerodrome—hangars and two runways—from 1930 to 1941. The Marsh Crust extends from the Oakland Estuary to Bayport and over to central Alameda Point. A city ordinance requires a permit before digging into the Marsh Crust to ensure safe handling.
The 37-acre North Housing area lies adjacent to the new Alameda Landing residential neighborhood. The site currently contains 51 residential structures with 282 three- and four-bedroom units constructed in 1969. With the possible exception of the two acres going to Habitat for Humanity, all of the units will be demolished to make way for new construction.
The Housing Authority will build 90 units of supportive housing that will include a community center.
It is not yet determined what Habitat for Humanity will do with its parcel. The private developer area is currently zoned for 315 units of multifamily residential housing and may exceed that number if the density bonus is applied for.
The transfer of properties is expected in 2016. The auctioning of the for-profit North Housing Navy property will follow, but no firm timeline has been announced.
Edited version of article first appearing in the Alameda Sun.
Record of Decision Amendment for groundwater cleanup at OU5 – April 2015
North Housing amendment to NAS-Alameda Community Reuse Plan