Tag: Northwest Territories – Public Trust Land

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.

Soil cleanup planned at runway workshops area

Future recreational open space

The 4.18-acre cleanup Site 34 in the old runway area next to the Oakland estuary looks barren from a distance.  But up close there are concrete slabs and pavement, reminders 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.  Their draft work plan, which will be released on July 31, was discussed during a Navy presentation at the July 2012 Restoration Advisory Board (RAB) meeting. 

Site 34 aerial view. Old fuel dock to left of site. Runway at bottom is part of area where antiques faire is held.  Navy photo/graphic.

Based on more than 200 soil samples taken in prior years and this year, 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 1) vapor intrusion into residences is not a factor, as this land will become Public Trust Land on which housing is not permitted; and 2) 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 get out to 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.” 

Site 34 starts at concrete slab on far side of tree. Port of Oakland on right.  In late 1800s and early 1900s, trains travelled on tracks along the estuary where tree and slab are.

By the time the closure of the Navy base was announced in 1993, this workshop area had 12 buildings, 7 aboveground storage tanks, 2 “generator accumulation points” (waste storage), 15 transformers, and over 7,000 feet of aviation fuel line.  Between 1996 and 2000 everything except the concrete pads and pavement was removed. 

Building demolitions 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 metals 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.  They have 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.

Coastal marsh on Oakland estuary at Alameda Point Site 34. Port of Oakland on left. Old runway area on right. Looking east toward Alameda Main Ferry Terminal.

A 60-day public comment period on the work plan begins when it’s released on July 31.  The work plan will be finalized in January 2013.  Fieldwork is anticipated to take place January through April 2013.

Site 34, located in the Northwest Territories, is expected to be given to the City of Alameda in 2014.

Click here > Site 34 RAB Presentation  for more details.

Announcing the new reference tab at the very top of this blog called “Cleanup document libraries.”

Where Alameda Point’s cleanup is at year’s end

 

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The past year had some high points and low points in the cleanup process at Alameda Point.  Added delays, including a pile-driving surprise, were balanced out by steady progress.

The year saw, among other things, completion of a second Point-wide radiological survey of buildings and structures that identified two building interiors needing radium remediation, a new soil scan for radium on a section of the western runway area, replacement of a storm drain segment next to the Seaplane Lagoon, and preparation of the environmental document for the Berkeley Lab site, which will be useful whether we get the Lab or not.

Northwest Territories - Site 1 dump area, partly covered by runway

The contractor preparing to cover the old dump with rocks and soil at the northwest tip of Alameda Point delivered some embarrassing news to the Navy.  In the normal course of their duties, work-plan design testing revealed that the shape of part of the contamination did not match the official description.  You would think they could just process a work-order change.  But the Superfund law requires an additional two-year review process, which will push the completion of this open space opportunity to 2015.

At another cleanup project, the Navy drove over four dozen 30-foot steel electrodes into the ground to heat up the toxins and capture the vapor.  But before turning on the electricity, the contractor discovered they had hit a sewer line.  The project has since been idle for months awaiting a decision on how to proceed.

Seaplane Lagoon dredge dewatering pad - northwest corner

The big Seaplane Lagoon dredging project that began in January is certainly one of the most dramatic displays of cleanup.  Both the northeast and northwest corners of the lagoon were supposed to have been dredged by April and final soil disposal completed by year’s end.  But the contractor failed to meet the deadline and was let go.  A new contractor has been testing and removing existing soil, as well as doing extensive set-up over the past two months for the dredging of the northwest corner that will begin in January.

Another dredging project has just begun under the dock area next to the maritime ships.  They’re removing mud contaminated from two storm drain lines.  That project is on schedule.  It’s worth visiting the area to get a glimpse of the elaborate engineering needed to capture and clean water runoff from the mud.

Shinsei Gardens low-income housing located above ongoing groundwater cleanup

Less dramatic and seldom seen work is always ongoing.  Groundwater is monitored at cleanup sites to ensure cleanup goals are being met.  One example is the monitoring of the removal of benzene and naphthalene under Shinsei Gardens and vicinity.

Evidence of the Petroleum Program is also seldom seen, other than some white PVC pipes in the ground.  But besides the big fuel extraction projects, there is ongoing testing of pipelines and oil/water separators in order to develop a remedial plan.

Finally, and perhaps most important, getting the first, very large, no-cost land conveyance from the Navy next year appears to be on schedule.  To help make it happen, the Navy and regulators are planning on modifying cleanup goals by enacting restrictions against future ground-floor residential development near the east entrance to Alameda Point.

Originally published in the Alameda Journal.

Environmental Cleanup – Update on Site 1

Site 1 indicated by blue line. Yellow line indicates entire area used by Navy as a disposal area from 1943 to 1956. Red indicates waste pit that caused groundwater contamination. Navy photo and overlay.

Groundwater

The Navy is proceeding with plans to remediate contaminated groundwater at the old disposal site at the northwest tip of Alameda Point.  The contaminated groundwater is within the area known as Site 1, which encompasses over half of the old dump.  In one particular area of the dump, the Navy routinely dumped liquid waste material.  No one knows for sure how much of it was in drums that may still be rusting away, and how much was just poured into the pit.

Some current and former members of the Restoration Advisory Board (RAB) have long been concerned as to whether the size of the plume has been adequately characterized, meaning how wide and how deep.  The main issue is its proximity to the Bay and whether remediation measures will prevent any of the hazardous compounds from entering Bay water. Continue reading “Environmental Cleanup – Update on Site 1”

Point Being: Clean Ups and Downs

Dredging northeast corner of Seaplane Lagoon

Cleanup at Alameda Point continues to unfold. Every month the Restoration Advisory Board meets to stay apprised of the happenings and offer comments. The public is invited to attend on the first Thursday of the month, 6:30 p.m. at the rear of City Hall West at Alameda Point. Here are some highlights from the February meeting and a “Point Being” video update on the Seaplane Lagoon.

Site 1 at western end of Alameda Point in Northwest Territories - burn area in background - Bay Bridge in distance

Site 1 – Burn Area Larger Than Expected

There’s a glitch in the ditch at Site 1 out at the northwestern tip, in the Northwest Territories.  This is one of two of the Navy’s industrial dumps (aka disposal sites – the other one being Site 2 to the south on the Wildlife Refuge), and plans were on the calendar to begin the remediation plan on the 30-acre Site 1, which is set to become recreational open space, this year. But instead of 2013, it will now be 2015 before we are throwing Frisbees, riding the Bay Trail, or launching kayaks on the windy, incomparable western shore.

The plan was, and still is, to install a four-foot engineered soil cap on top of the site, after digging out and hauling away refuse from the burn area, where things like railroad ties were burned, which makes up a small part of the site. But as the Navy contractor was doing prep work for a detailed work plan, they discovered that the old burn area is larger than expected and that soil under the burn area “exceeded remediation goals,” which at the very least means more testing to find out what else is there.

Continue reading “Point Being: Clean Ups and Downs”