~Lactose, veggie oil to stimulate toxic-eating bacteria
Cleanup of contaminated groundwater between Alameda Point’s Seaplane Lagoon and Main Street will begin later this year, according to the Navy. The cleanup area is directly south of the Site A residential and commercial parcel slated for groundbreaking in a few months. It is one of the most difficult environmental cleanup areas to remedy at Alameda Point, which is why it has taken 20 years to figure out what plan to implement. The Navy’s contractor presented the cleanup plan at the March 9, 2017 Restoration Advisory Board meeting at Alameda Point.
A cleaning solvent called trichloroethene was used in the Navy’s industrial repair and refurbishing operations in this area. The solvent leaked into the ground to depths of 70 feet and spread around nearly 19 acres. Industrial activities included the Aircraft Engine Test Facility in Building 360, which is the large building next to the Main Street soccer field, along with the Engine Test Cell in Building 14, and the Ship Fitting and Engine Repair Facility in Building 162.Continue reading “Toxic groundwater to be cleaned up using bacteria”
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.
The Navy has spent more than 15 years cleaning up contaminated groundwater underneath two former gas station sites at Alameda Point. They are still at it, but it’s not because the Navy is slow or lacking in commitment and expertise. It’s the nature of groundwater cleanup, which involves intermittent treatment efforts.
In July, the Navy’s contractor returned to the old gas station and car wash site on West Pacific Avenue at Main Street and to the old commissary gas station site at West Tower Avenue and Main Street across from Bayport. It’s the third visit to these sites to eliminate petroleum hydrocarbon contamination in groundwater, in addition to earlier removal of underground tanks, fuel lines, and soil. The contaminants are located from 2 to 16 feet below ground surface.
The goal is to bring the property up to the public health and environmental standards required for the future commercial and residential uses previously determined by the city.
“When groundwater contamination is involved, such as at the two former gas stations, cleanups often involve multiple phases, each building upon earlier accomplishments,” said Dr. Peter Russell, who has been reviewing Navy cleanup plans and preparing cleanup-related documents on behalf of, and at the direction of, the city since 1997. “As long as all imminent health and environmental risks are eliminated early on, often the most cost-effective approach to complete remediation is incremental,” explained Russell. “In contrast, a massive initial remedial effort that is sure to achieve all remedial goals in one pass would likely involve over-sizing the treatment system, which is more disruptive and expensive than a phased approach.”
During previous cleanup visits, the Navy used a vapor extraction system to remove the bulk of the petroleum contamination. The process involves pumping air into numerous pipes, called wells, which extend into the water-saturated zone where the contamination is. The air pressure creates vapor that is part air, part water and part petroleum. The vapor is then sucked out through another set of wells, and the petroleum vapors are captured in drums of granulated charcoal, while the water is shunted off to a separate container.
The method of blowing bubbles in mud and sucking out the air sounds unsophisticated, but it works. After running the system in 2013 and 2014 at the West Pacific Avenue gas station site, for example, the level of one contaminant, benzene, went from around 1,000 micrograms per liter down to 58, bringing the contamination low enough to allow indigenous bacteria to finish the job.
The Navy returned to these sites in July and, in this phase, they came to help natural bacteria finish up the job. Allowing bacteria to clean up petro chemicals through natural digestion is called bioremediation. To be effective and not take a century to eliminate the problem, the bulk of the chemicals need to first be reduced to concentrations that do not overwhelm the bacteria.
At both gas station sites the Navy used a special product designed to foster growth of natural bacteria in the ground, which includes a form of time-release peroxide that turns into oxygen over a period of 12 months. An oxygen environment is necessary for the bacteria to digest petroleum. The bacteria utilize the hydrocarbons (hydrogen and carbon) in the petroleum chemicals as part of their metabolic processes and convert them into carbon dioxide, water, and microbial cell mass. Water samples will be taken at three, six, and nine months after the July injections to evaluate effectiveness.
“The Navy’s gas station remedial program is comparable to the private sector gas station cleanup program,” said Yemia Hashimoto, Engineering Geologist with the San Francisco Bay Water Board. “The cleanup requirements are similar and the required timelines for project completion are similar.” The Water Board is a California state agency and is the lead regulatory agency overseeing the Navy’s petroleum cleanup program.
The other type of groundwater contamination encountered at Alameda Point comes from a chlorinated solvent used in cleaning aircraft parts. Unlike lighter-than-water petroleum products, chlorinated solvents can sink through the upper water zone to a depth of 30 feet or more and complicate cleanup. But solvent cleanup still relies on a phased cleanup approach, often employing bacteria in the final phase.
A Navy contractor will be cleaning up groundwater in part of the Town Center area next to the Seaplane Lagoon by injecting a solution of cheese whey, emulsified vegetable oil and water into nearly 200 wells that go down between 30 and 40 feet. The whey and vegetable oil will cause natural bacteria to flourish that will feed on the toxic trichloroethene (TCE) solvent causing it to break down.
According to the Navy, this type of food-stimulated bacterial bioremediation is common. The cheese whey is similar to the powdered whey products found in grocery stores. It will be delivered to the site already diluted in water. A hose will be connected to a fire hydrant and hooked to a metering device that will mix the whey and oil solution with municipal water as it is pumped into the wellheads.
The work is expected to begin in 2015, with periodic visits and testing until 2020. The first year of operation the contractor will make two visits of 35 days each. During each of these work periods they will inject 246,000 gallons of whey, oil, and water solution into the ground, allowing gravity to disperse the liquid.
The goal of the cleanup is to minimize the potential for hazardous vapors entering buildings, and chemicals migrating into the Seaplane Lagoon. TCE is an industrial solvent used to degrease metal parts. It was heavily used at aircraft and ship engine repair facilities on the site. A leak from a rail car is believed to be one of the major sources of the plume.
The 33-acre cleanup area is immediately to the south of the Navy jet on West Atlantic Avenue at the east entry to Alameda Point near Main Street. It is within the 150 acres of the Town Center that the city is seeking to develop in the near future. In April, the city council sent out requests seeking qualified developers interested in residential and commercial projects. The cheese and veggie oil cleanup area will not be transferred to the city until at least 2020 when cleanup has been certified to have met its goals.
Cleanup of fuel in groundwater ended about four years ago at an old fuel distribution point on the north side of the jet monument.
Below is an audio and image presentation from the Alameda Point Restoration Advisory Board meeting on May 8, 2014.
Under the petroleum cleanup program the Navy has been removing tanks and fuel lines and cleaning up spills and fuel leaks dating back to the early 1990s before the base closed. Most of the tanks and fuel lines were removed within three years after the base closed in 1997.
Cleaning up leaked and spilled fuel has been slower, often involving running a vapor extraction pump 24/7 for years. In a few cases, a groundwater contamination site will require a callback after the initial work is completed. The Navy’s routine monitoring of groundwater, even after cleanup work has been completed, is aimed at determining whether there is a rebound in contamination readings and follow-up treatment is necessary. Three such sites needing more work, on land recently acquired by the city, are currently undergoing follow-up treatment at the Navy’s expense.
Two of the sites once served as automobile service stations. The other site is where fuel was removed from planes before they were serviced.
The treatment method is simple. Air is pumped into the ground where the contamination is the highest. This causes the petroleum products to vaporize, and then a suction system draws out the vapors into a barrel of charcoal. The air injected into the ground also helps natural petroleum-digesting bacteria to grow.
Solar-powered cleanup for the first time at Alameda Point
Air injection/extraction pumps at the two former service station sites are running on electricity from the grid. At the former plane de-fueling site next to Building 410, however, the Navy is using a solar-powered pump for the first time anywhere at Alameda Point. Derek Robinson, the Navy’s Environmental Coordinator, explained the solar choice saying, “Electricity is not optimum because the overhead electrical tie-in is located too far away for the system to be tied in to the grid cost effectively. The solar units provide the power necessary to operate the air sparging and soil vapor extraction system at a competitive price.” The only other option was a combustion engine pump running on gas or diesel.
“The battery storage system is traditional lead/acid batteries,” said Robinson. “The solar array charges storage batteries allowing the system to store energy and operate in cloud cover and beyond strictly daylight hours; however, the system is designed to power off the blowers once the voltages drop below a preset level,” he said.
Sustainable Technologies, located just a block away at Alameda Point, constructed the entire rig. It consists of solar panels, a box full of lead-acid batteries, a circuit panel, and a pump. Ironically, Sustainable Technologies is located on a Superfund site that will take another six years to clean up.
The area next to Building 410 where the fuel spills occurred has had a number of cleanup actions going back to 2002. “Corrective actions under the petroleum program were conducted in 2002 and 2011 and a remedial action under the CERCLA [Superfund] program was conducted between 2005 and 2006,” said Robinson.
Work will continue until the end of the year. The Navy will always be responsible for returning to do more cleanup work if groundwater testing shows some of the contamination was missed.
Locations of three petroleum cleanup sites currently undergoing more cleanup work.
The city has announced that over 500 acres of land will be transferred from the Navy to the city on June 4, 2013. It will be the first – and largest – of a four-phase schedule of land transfers to the city. One of the areas that won’t be transferred this year is located at the main entryway into the future Town Center currently being designed.
Driving into the “East Gate” on West Atlantic Avenue to Ferry Point Road at the Seaplane Lagoon takes you through part of the future Town Center – and through a major environmental cleanup area called Operating Unit (OU) 2B.
Plans for a vibrant mixed-use Town Center to kick off redevelopment are now in the design stage, but 33 acres on the south side of West Atlantic Avenue won’t be transferred to the city until 2019. That’s when contaminated groundwater is expected to be cleaned up to commercial standards, allowing the Navy to turn over the land.
The overhaul of aircraft and ship engines in this area led to major contamination of groundwater with trichloroethane and vinyl chloride, as well as pockets of soil contamination. After testing various cleanup methods on the contaminated groundwater area – called a plume – the Navy and regulatory agencies have decided to rely mainly on bioremediation – natural bacteria – to degrade the contamination.
Soil hot spots will be removed, except under buildings. Future developers will be responsible for soil under buildings once they are demolished.
One of the groundwater hot spots close to the Seaplane Lagoon was successfully treated last year with a heat and vapor extraction system. Some of the other hot spots are impossible to treat with electrical heating because of underground power lines nearby.
The Navy has found bioremediation to be the most practical method to finish the job. Work details will be finalized later this year. Bioremediation can involve injecting new bacteria, but here it will likely mean injecting oxygen to spur the growth of existing bacteria. It’s the carbon atoms in the chemical contaminants that are attractive to bacteria, allowing them to naturally disassemble a chemical compound.
Someday, decades from now, the danger from vapors entering buildings will be low enough to permit ground floor residential use. Current restrictions imposed under the Navy’s cleanup plan will prohibit ground floor residential, but will allow residential use above the first floor, provided an approved vapor barrier and venting system is installed under any new construction. First floors will be allowed to have commercial uses once the city receives the land in 2019. Groundwater monitoring wells around the cleanup area will remain usable and accessible for regular monitoring for at least 20 years.
The cleanup area north of West Atlantic – 13 acres called Site 3 – will be turned over to the city next year following removal of several contaminated soil hot spots containing lead and other contaminants. Some of the contaminated soil areas are under building slabs on Site 3 and will be the responsibility of a future developer. All of the buildings in the East Gate cleanup area called Operating Unit (OU) 2B – 46 acres – are expected to be demolished rather than reused.
Site 3 north of West Atlantic was also heavily contaminated with jet fuel around an area where underground fuel storage tanks were once located. The former storage tank area is west of the jet monument and is still dotted with white pipe stubs once connected to a maze of cleanup pipes. The jet fuel cleanup was completed two years ago under the Navy’s Petroleum Program using a vapor extraction system. Removal of underground tanks and fuel lines was completed in 1999.
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.
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.
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.
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.