Navy housing site safe to transfer

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.

Center courtyard in former Navy housing area called North Housing. Looking north/northeast.
Center courtyard in former Navy housing area called North Housing. Looking north/northeast.

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.

Draft map prepared by the city of Alameda showing proposed Housing Authority, Habitat for Humanity, and private developer parcels. Pending final approval. Dusty rose area going to Housing Authority, blue to Habitat for Humanity, tan to private developer. Click on map to enlarge.
Draft map prepared by the city of Alameda showing proposed Housing Authority, Habitat for Humanity, and private developer parcels. Pending final approval. Dusty rose area going to Housing Authority, blue to Habitat for Humanity, tan to private developer. Click on map to enlarge.

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.

Time lapse map showing former marshland where North Housing is now located. Source: US Geological Survey Historical Topographic Map Explorer.
Time lapse map showing former marshland where North Housing is now located. Source: US Geological Survey Historical Topographic Map Explorer.

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.

Future Housing Authority property, with new Alameda Landing houses in the background.
Future Housing Authority property, with new Alameda Landing houses in the background.

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.

Appendix pelican graphic

Record of Decision Amendment for groundwater cleanup at OU5 – April 2015

North Housing amendment to NAS-Alameda Community Reuse Plan

Map showing two groundwater cleanup areas in OU-5.
Map showing two groundwater cleanup areas in OU-5.
Control module with pumps for groundwater cleanup system waiting to be hauled away from North Housing.
Control module with pumps for groundwater cleanup system waiting to be hauled away from North Housing.
Charcoal filter tank to remove benzene and naphthalene from groundwater vapors, waiting to be hauled away.
Charcoal filter tank to remove benzene and naphthalene from groundwater vapors, waiting to be hauled away.

North Housing

North Housing, Alameda

North Housing

Typical current condition of North Housing interiors.
Typical current condition of North Housing interiors.
Typical current condition of North Housing interiors. Photo date: November 19, 2015.
Typical current condition of North Housing interiors. Photo date: November 19, 2015.

Mosley Ave. right of way

Draft North Housing site map, with Mosley Avenue connection details. Click on map to enlarge.
Draft North Housing site map, with Mosley Avenue connection details. Click on map to enlarge.
1899 topographical map of western Alameda showing marshland. Source: US Geological Survey Historical Topographic Map Explorer.
1899 topographical map of western Alameda showing marshland. Source: US Geological Survey Historical Topographic Map Explorer.

Environmental cleanup update – November 2014

Navy environmental cleanup operations at Alameda Point ran the gamut during the summer and fall of 2014.

Operations included using bacteria to clean up groundwater, grinding radium out of a building floor, digging up lead-contaminated soil, constructing a metal shoreline waste barrier, digging up shoreline waste, preparing to install a 30-acre soil cover, constructing a new shoreline wetland, checking drain lines for contamination with cameras, and demolishing a several-acre temporary concrete drying pad near the old Control Tower.

Aerial view of Site 1 cleanup area at northwest tip of Alameda Point, showing newly installed waste isolation barrier along Bay shoreline, piles of contaminated soil in horseshoe shaped area that were excavated from watery pit on right, and stockpiled soil on old runway to be used for soil cover.  A wetland area will be constructed on clear strip on left along Oakland Estuary.  Navy photo.
Aerial view of Site 1 cleanup area at northwest tip of Alameda Point, showing newly installed waste isolation barrier along Bay shoreline, piles of contaminated soil in horseshoe shaped area that were excavated from watery pit on right, and stockpiled soil on old runway to be used for soil cover. A wetland area will be constructed on clear strip on left along Oakland Estuary. Navy photo.

Continue reading “Environmental cleanup update – November 2014”

Navy could shut down groundwater treatment at housing site

The Navy often hears calls to increase its environmental cleanup effort.  Now, the community and regulators are hearing a call from the Navy to eliminate one cleanup effort altogether.

North Housing area next to Island High School where benzene plume is located.

Since 2009, several acres of the area north of Bayport that includes the Shinsei Gardens affordable housing development, former Coast Guard and military housing, the closed Island High School, and the Woodstock Child Development Center have been undergoing groundwater treatment to eliminate hot spots of benzene and naphthalene vapors.  Shinsei Gardens also included special building slab engineering in its design as an extra precaution against vapor intrusion.  The Navy now says that its groundwater treatment system is unnecessary and should be shut down.

Shinsei Gardens
Shinsei Gardens

In a report issued in December 2012, the Navy said the underground vapor extraction system called biosparging is not making the area any safer for human habitation.  Biosparging is a form of bioremediation that uses air and oxygen injections to stimulate the growth of naturally occurring bacteria, which break down toxics.  In this case, the contamination is composed of waste material discharged from an Oakland coal gasification plant and an Alameda oil refinery that operated long before the area was filled in.  The contamination layer has been dubbed the Marsh Crust.

OU-5 map with plume & landmarks

The Navy’s report points to the initial studies in the area that showed no risk from vapors.  The only justification for the remediation in the first place was the limited risk of contact with water through non-potable uses, since drinking water will always be supplied by East Bay Municipal Utility District. 

Now the Navy says that even non-potable uses are impractical and off the table due to high levels of minerals such as salt.  With no way of coming in contact with water containing benzene and naphthalene, the Navy decided to review the data for vapor exposure and concluded there is plenty of evidence to turn off the pumps.  The biosparge system was designed to run for eight years in order to reach its cleanup goals.

The Navy’s December 2012 Technical Memorandum is seeking to amend the original cleanup decision — known as the Record of Decision (ROD) — for this cleanup area.  They will need the concurrence of the regulatory agencies:  the regional Water Board, state Department of Toxic Substances Control (DTSC), and the Environmental Protection Agency (EPA).  But the EPA and DTSC are not ready to agree without further testing. 

According to EPA’s Chris Lichens, “The Navy’s conclusions are not based on current data, site conditions, or investigation methods.  Before proceeding with a ROD Amendment,” he said, “the agencies would like the Navy to collect additional data to verify that vapor intrusion would not present a significant risk in the absence of biosparging.”  Lichens added, “Along those lines, EPA and DTSC jointly prepared recommendations for additional groundwater, soil vapor, and indoor air sampling and provided those recommendations to the Navy.  The Navy has not yet agreed to collect additional data, although we are still discussing it with them,” he said.

Originally published in the Alameda Sun.