Ending threat of solvents in groundwater leaching into San Francisco Bay

Site 1 at the northwestern tip of Alameda Point was used as the principal disposal area for all waste generated at Naval Air Station-Alameda from 1943 to 1956.  This disposal area, which was once part of the Bay, was created by sinking pontoons and barges in the Bay and backfilling with dredge soil.

Disposal of cleaning solvents and petroleum products at one unlined pit within the landfill resulted in a groundwater plume that poses a threat of leaching into San Francisco Bay today.

In the 1990s the Navy installed an underground barrier system, called a funnel and gate permeable reactive barrier, to stem the flow of contaminants into the Bay.  It was not a permanent solution.  In July of this year the permanent solution began with the injection of neutralizing chemicals into the plume.

Protecting marine life

San Francisco Bay at Alameda Point western shoreline where threat of solvent leaching exists.

Most cleanup activities around the base are aimed at eliminating direct health risks to humans, such as from soil or from vapors that could enter a building.  In a few cases, the cleanup is focused first on direct impacts to marine life such as fish, which could in turn cause health problems for people who eat them.

The cleanup effort at the Site 1 plume is one of those cases.  This effort will keep toxins — solvents, petroleum products, and metals — from ever leaching into the Bay, being ingested by fish, and then consumed by humans.  The effort will also reduce unacceptable levels of vapors that are escaping directly above the plume.  The future use of the site will be restricted to open space recreational.

The process

July 2012 – Manifold system of hose lines that send oxidant chemicals to individual wells that go into the underground plume contamination area. Navy photo.

The chemical injection process, called In Situ Chemical Oxidation (ISCO), is accomplished by injecting oxidants (catalyzed hydrogen-peroxide and sodium persulfate) into the plume through injection wells.  “These oxidants produce short-lived reactions that directly destroy the targeted contaminants,” according to the Navy.  Groundwater tests will determine if further treatments are necessary.

Tanks of chemicals for neutralizing solvent plume. Shown as work area being set up in June 2012.

Treatments will continue until either the groundwater is clean enough, or the solvent and petroleum concentration has been reduced by 75%.  Once they get to 75% reduction, further injections are more or less a waste of money.  From then on, the contaminant concentration is low enough that the remainder will either degrade or disperse and dilute naturally without posing a risk to fish or humans.  This process is called natural attenuation and is often relied upon to finish the job when the bulk of contaminants are neutralized and treatment methods no longer yield effective results.

The groundwater plume is also contaminated with metals consisting of arsenic, copper, mercury, nickel, silver, and zinc.  The metals problem will, in theory, be taken care of when the solvents and petroleum products are eliminated.  This will cause the chemistry of the groundwater to change, which in turn will cause the metals to no longer remain dissolved in the water.  The metals will return to their solid state and remain where they are.  That’s the theory.

But to make sure it’s working, there will be a long-term groundwater monitoring program to make sure the metals aren’t moving.  If problems arise in the future, the Navy will have to come back and design a new remedy.  The Navy is responsible for the landfill’s contents staying in place in perpetuity.

Map of Site 1 disposal area with arrow from left indicating plume treatment area. Map also shows outlines of individual unlined pits that were used for disposal of waste. Half of the area is now covered by runway.

The Navy opted not to remove the landfill contents because of the $93 million price tag and because the risk of contaminant releases was deemed low.  A new set of environmental concerns associated with digging up and hauling away a landfill was also cited during the decision process.

The groundwater plume being treated is approximately 30 feet wide by 160 feet long, and it occurs mainly between depths of 5 and 10 feet below the ground surface.

Site 1 groundwater treatment work underway in July. San Francisco in background. Navy photo.

Delay on soil cover

All of 30-acre Site 1 will eventually be covered with soil and seeded with native grasses.  Work on the soil cover was delayed when the contractor discovered that the part of the landfill once used for burning waste was larger than expected.  The documentation has to go back through the review process, with a work plan for the soil cover hopefully prepared and ready to implement by 2014.

Protecting the California Least Terns at the Alameda Point Wildlife Refuge

Volunteers distributing oyster shells on nesting site in April 2012

The California Least Terns are arriving back at Alameda Point’s wildlife refuge to lay their eggs and raise their young.  The volunteers, who help maintain the site, and the US Fish & Wildlife Service (USFWS) biologist responsible for the tern colony, have never left.  They carry out maintenance tasks during the non-nesting season – September to early April – as well as help monitor bird behavior during the nesting season.

California Least Tern, with chick under tile, at Alameda Point

The California Least Terns return to California every April from Central America.  The old Navy runway area at Alameda Point is among the limited number of sites where these endangered birds come to nest.  Driven to adapt to a loss of undisturbed beach habitat, they began nesting at Alameda Point decades before the Naval Air Station closed in 1997.

While Navy jets would be disturbing for humans to live next to, for the terns the movement of the jets was predictable and easy to avoid.  That’s not the case on an increasing number of beach areas where people and pets can easily trample eggs in the sand and frighten the adult birds.

The Alameda Point colony is considered the most successful for this bird.  It is believed that the success at Alameda Point has led to new colonies elsewhere in California.

Looking south on a rainy day in April 2012 on the Alameda Point nesting site for CA Least Terns
Oyster shells on Alameda Point nesting site for CA Least Terns

Volunteers are recruited by the Friends of the Alameda Wildlife Refuge, a committee of the Golden Gate Audubon Society.  Activity at the Least Tern nesting site started ramping up in January this year as it always does, with guidance from the USFWS biologist.  Volunteers perform tasks such as removing weeds, repairing the mesh barrier that keeps chicks from wandering off or getting injured in the chain link fence around the nesting site, and distributing oyster shells to confuse hawks and other flying predators that often circle overhead during the nesting season.

Every year the US Fish & Wildlife Service re-positions all of the numbered cinder blocks that establish a grid pattern for recording bird behavior.  The blocks, along with all the other “tern furniture” – wooden A frames and clay tile that chicks shelter under and in, oyster shells, driftwood – are gathered up and set to the side after the nesting season.  This allows for easier weed control and for the sand and gravel surface to be graded.

The grid blocks are placed into position using a global positioning system for complete accuracy.  When Tern Watch volunteers or the Fish & Wildlife biologist observe activity, they record the data according to a grid letter/number.  Without a grid system, it would be difficult to record accurate data for hundreds of eggs and chicks, i.e., did a predator steal an egg last night, or is that the nest that had only one egg?

This year there are two training sessions for the Tern Watch program.

The public is invited to take a bus tour to the site on June 16th.  The annual event is hosted jointly by USFWS and the East Bay Regional Park District.  The bus tours leave from the Crab Cove Visitors Center in Alameda.  Advance registration is required and is handled through the park district.  (See comment below.)

Wetlands, Trails, Natural Habitat Concept Drawings for Alameda Point

Proposed Flight Park and Wetlands

The borderless ecosystem – On September 1, 2011, Golden Gate University’s Center on Environmental Law published their proposal for a unified planning process and expansive view for open space at Alameda Point.  The central theme of their effort is that the true potential for conservation at Alameda Point lies in thinking of the area as one contiguous ecosystem of land and water.  In doing so, not only is there benefit to wildlife and the environment in general, there is also benefit to our efforts at economic development by making Alameda Point a highly desirable location with a signature identity – Flight Park.

Perimeter boardwalk (Bay Trail) through park

Flight Park is their suggested name for a unified open space system that would bring to mind larger-scale landmark open space systems like the Golden Gate National Recreation Area.  Bringing together regional, state, and federal agencies to adopt and implement conservation efforts will be far more effective in the long run than waiting for, say, the VA to appropriate money for habitat conservation (not their core mission), or the city of Alameda getting enough attention to secure millions in wetlands monies. 

Moving the VA facilities – Perhaps the most controversial proposal within the Flight Park concept is moving the proposed VA facilities off of the Wildlife Refuge to a spot further east at Alameda Point.  While coming late in the process for transferring land to the VA, it is not without merit.  The Golden Gate Audubon Society has long opposed the sighting of VA buildings on the Wildlife Refuge as an intrusion into the habitat of the endangered California Least Tern.  The Flight Park designers see the VA buildings as a visual obstruction on an otherwise wild and open bay front parcel.

Boardwalk through proposed wetlands

There is good reason for the VA to work with the City of Alameda on moving their buildings, if not their columbarium, closer to the old “Main Gate” on the north side of Alameda Point.  Services will be easier to get to for veterans, and the infrastructure to their site will be less expensive.  There is still time – the VA has not spent their $17 million for this year on design, and therefore they have not requested money for the project in next year’s budget proposal.

The East Bay Regional Park District has been ready and willing to take on the management of regional park facilities at Alameda Point for over a decade.  In 2009 they set aside $6.5 million for Alameda Point shoreline restoration and the Bay Trail.

Existing wetlands on Northwest Territories

Wetlands Mitigation Bank – Professor Paul Kibel, co-director of the Center on Urban and Environmental Law and leader behind the Flight Park concept, argues that there is also funding potential in the creation of a Wetlands Mitigation Bank such as has been created in many California communities to accumulate funds for creating or restoring wetlands.  An experienced environmental lawyer, he has offered to assist the city in any way he can in setting up such a wetlands bank.  One of our first contributions would likely come from the Navy, which will owe us some wetlands due to their coming remediation plans for the Northwest Territories.  Typically, two acres of wetland must be created for each single acre removed.

Seaplane Lagoon grassland promenade with Control Tower converted to nature observation center

In Sum – The Flight Park drawings offer an inspiring look at what could be at Alameda Point.  It is a vision that merges well with recent sustainability presentations that call for diverting storm water to wetlands and marshes at Alameda Point.  Urge our city council to discuss this initiative.  It would build on Alameda’s reputation as a city dedicated to environmental sustainability.

CUEL Booklet on Flight Park at Alameda Point

More images in the Environmental Report’s Flickr gallery.

The Nesting Ospreys of Alameda Point – with video

The spring of 2011 saw the return to Alameda Point of a nesting pair of ospreys.  This pair set up their nest on the same light stand at the entrance to the Seaplane Lagoon as another osprey pair, or perhaps the same pair, had done in 2009.  Unlike 2009, this year the area is fenced off for cleanup work, making it difficult to get good photographs.

Remarkable in flight

It was a pleasure to watch the adults change shifts on the eggs and go off to catch fish.  Although they may sometimes prey on small ground dwelling animals, their diet is normally restricted to fish.  Often they could be seen heading north across the Seaplane Lagoon just inches above the water attempting to grab a fish.  What was remarkable to witness was their flying technique.  The osprey that I watched one evening was propelling itself just inches above the water for a few hundred feet, skimming the surface with its unique opposing claws ready to clutch a fish.  Up would go the wings to almost full vertical, and then come down in an arcing motion, cupping the air and thrusting it forward.

osprey hunting for fish
osprey with fish

When they returned with a small fish, they would usually perch on either the tip of an old metal post next to the nest or further west on the breakwater on a post with a horizontal arm.  After having their fill, they would share with their mate.

Unfortunately, vacation plans interrupted my photography before the chicks hatched and fledged.

While the osprey is not an endangered species, it is certainly an environmental asset and a beautiful creature to watch – so much so that many communities throughout the U.S. build perches around lakes and bays to attract ospreys during the nesting season.

Alameda should preserve nesting sites

Alameda should emulate these efforts and adopt a policy of not only permanently preserving the old light beacon stand that was used this year; we should also refurbish the other one on the east breakwater that is tipped over and hanging on by a chain.

We should make provisions for when the cleanup fencing is removed.  Perhaps a small fence at the entrance to the west breakwater to prevent deliberate or uninformed intrusions into the “nesting space.”  We could have organized viewing programs during nesting season.  One way to generate interest in the ospreys would be to install video cameras in some new poles next to each nesting platform.  A pole with a horizontal perch would be more useful to the osprey and a good way to have one camera facing into the nest and another one facing out toward the lagoon with streaming video.

To place the protection of osprey nesting sites in perspective, it is instructive to know that if the light stand used for nesting were a tree in a logging area of California, it would be illegal to cut it down.  Nesting sites are protected in our forests, and they should be protected here.  Without a proactive effort now, I fear that one day we will find that the old historic light stands have been thrown away.

The open space and wildlife resources that we have at Alameda Point are priceless.  We should make an effort to preserve them, especially when we have visitors like the ospreys.  

Click here > osprey slideshow on Flickr for more images