Alameda Point 2012 environmental cleanup review, and busy year ahead

Cleanup activity at Alameda Point in 2012 started where it left off in 2011 — at the Seaplane Lagoon.  The northwest corner of the lagoon was the site of the second and final phase of lagoon dredging, which targeted sediment that had been contaminated near storm drain outfalls.  With dredging completed by spring, the sight of Americas Cup racing yachts arriving at their temporary dock in the lagoon seemed to be a harbinger of the approaching end of the Superfund era at the Point.

Dredging northwest corner of Seaplane Lagoon
Dredging northwest corner of Seaplane Lagoon

Just outside the Seaplane Lagoon, another dredging operation was started and finished at one of the maritime ship piers where the Cape Orlando had been docked.  By November, the massive ship was back at dockside, hull lights glowing at night.

Dredging Pier 1 wharf area
Dredging Pier 1 wharf area

In one of the most complicated and contaminated areas to the east of the Seaplane Lagoon, cleanup work began at an area 30 feet below ground where a cleaning solvent used on aircraft parts had seeped into the groundwater.  After driving a series of metal bars down to the contaminated area, the soil, groundwater, and solvent were heated to just below simmering by means of electricity.  This turned the water and solvent into vapor, which was then vacuumed out into a filtering system through a series of pipes. 

Heat treatment and vapor extraction - OU-2B
Heat treatment and vapor extraction – OU-2B

At the far end of Alameda Point on the northwest landfill, the Navy relied on chemicals, rather than heat, to do the cleanup on a small portion of the site.  Dozens of hoses snaking around the site to the injection wells delivered an oxidizing mixture of neutralizing chemicals into a pocket of solvents.  Without this remediation, the solvents had the potential to reach the Bay.

Injecting oxidizing chemical into solvent plume - Site 1.  Navy photo.
Injecting oxidizing chemical into solvent plume – Site 1. Navy photo.

The year ends with a cloud of controversy over the Navy’s plan for leaving drain pipes under the old Naval Air Rework Facility — Building 5.  Letters from both the Restoration Advisory Board (RAB) and the city call for the complete removal of any lines containing radium paint waste.  The Navy ruled out a more costly alternative that would remove all the contaminated pipes.  The city challenged this decision, in part, on the ground that the Navy’s cost estimates for a thorough job are inflated and have asked that they reconsider.

Building 5
Building 5

Also in Building 5, plans to remove above-ground radium contamination from floors, walls, and ceilings in the mezzanine area will get underway within weeks.  This area is where aircraft dials and markers were painted with radium paint that provided visibility in the dark.  A final scanning investigation to detect radium, using sophisticated equipment employed in the decommissioning of nuclear power plants, found dozens of pie-sized irregular areas where radium dust had embedded in the surfaces.  This project will conclude two decades of scanning and radium removal efforts in Building 5 and other buildings.  Around $50 million has already been spent replacing drain lines leading to the lagoon under the surrounding tarmac, and dredging the lagoon, due to the disposal of radium paint and other chemicals down storm drains.

Scanning a wall for radiological contamination.  Navy photo.
Scanning a wall for radiological contamination. Navy photo.


2013 will see the long-awaited final soil cover installed on the waste disposal site called Site 2 on the southwest corner of the wildlife refuge.  It will be the largest engineering project since the runways were expanded in the 1950s, with over 200,000 cubic yards of clean soil being barged in from Decker Island in the Sacramento River.  It will be seeded with California native flowering grasses selected by the RAB.  This is the controversial dump that led the US Fish & Wildlife Service to balk at accepting the land for a wildlife refuge ten years ago.  Since then, this dump has seen numerous reviews and a new plan that the US Environmental Protection Agency, regional Water Board, and state Department of Toxic Substances Control will be signing off on shortly.

Site 2 underground dump on southwest corner of Alameda Point.
Site 2 underground dump on southwest corner of Alameda Point.

2013 will end with commencement of a similar soil covering operation on the nearby landfill on the northwest corner of Alameda Point called Site 1.  Both landfill areas will be safe for open space recreational activities when completed, but will be limited to hiking trails rather than mowed playing fields in order to maintain soil-stabilizing vegetation. 

Northwest corner of Alameda Point where soil cover will be installed.
Northwest corner of Alameda Point where soil cover will be installed.

Groundwater cleanup back on track at heat treatment site

The groundwater remediation project between two buildings near the East Gate entrance, in the area known as Operating Unit 2B, finally got underway after a long delay in startup since last spring.  

During set up, one of the 30-foot-long steel electrodes driven into the ground to generate heat struck a plastic sewer line.  The sewer line was not on any maps and was undetectable through scanning since it is not iron.  Operation of the system began last month after a sewer line bypass was installed, and it will continue through May.

Heating and extraction of solvents in groundwater between East Gate entrance and Seaplane Lagoon.

The contamination is from nearby aircraft maintenance operations that resulted in chlorinated solvents, used in cleaning aircraft parts, ending up deep underground in the groundwater.  Of the three most common methods for cleaning up groundwater contaminated with solvents and fuels – pumping in neutralizing chemicals, heating up the ground to vaporize and extract the contamination, and bioremediation using microbes – the heat treatment method was chosen for this site because it is the fastest.

Graphic illustration of heat treatment system. Brown electrodes are heated with electricity, which heats the soil and groundwater, creating steam and toxic vapors that are sucked out into red pipe. Navy graphic.

It takes weeks for the ground to get to the target temperature of 194 degrees, which is the temperature at which the solvent boils and turns to vapor.  Pipes at ground level suck the vapor out of the ground and channel it through a large pipe to the granulated activated carbon filter system.

Granulated activated carbon filter system in tanks. Water vapor and toxic vapors are captured and separated.

Other groundwater contamination nearby will be treated by a different method not yet announced.  The Alameda Point electrical substation is near the other treatment area, and underground electrical lines leading every which way preclude the use of electrodes to heat the groundwater.

See also, “Cleaning up a toxic groundwater plume using heat.”

Click here > for background info on this cleanup area.

Cleaning up a toxic groundwater plume using heat

Hoses carry vapors to large pipe that leads to filter system. Vapors are created using high-temp electrodes that extend 30 feet into the ground. Seaplane Lagoon and San Francisco are in background.

There are various methods to clean up groundwater contaminated with solvents and petroleum products. Beneficial chemicals can be injected to neutralize the toxic chemicals.  Sometimes bacteria, either those naturally present or some that have been added, can do the job.  In some cases at Alameda Point the Navy inserts steel beams called electrodes into the ground that are hooked up to their own power line.  They dial up the power to 1,100 amps (a household electric stove is around 40 amps), and let the heat turn the chemicals into vapor.  This is the method the Navy is using in a limited application just east of the Seaplane Lagoon. Continue reading “Cleaning up a toxic groundwater plume using heat”