chlorinated solvents – Alameda Point Environmental Report

Recent revelations of falsified cleanup data at Hunters Point Naval Shipyard in San Francisco have caused many people to wonder about the integrity of cleanup at Alameda Point. Can we trust the Navy’s reports concluding that goals have been met and land is suitable for transfer to the City?

The Navy thinks we can. “To date, the Navy found no indication of data falsification at Alameda,” said Cecily Sabedra, Navy Environmental Coordinator for Alameda Point.

But more importantly, the rigorous and extensive testing requirements of cleanup at Superfund sites suggest that the process itself is what the public should look to for reassurance. The data review process is exactly why a couple of employees were caught handing in fake soil samples at Hunters Point.

Groundwater cleanup is a good place to look at how the process has been working at Alameda Point, considering that is where the majority of the contamination has been. The groundwater contamination resulted from releases of jet fuel and cleaning solvent and two leaky gas stations. This cleanup has left the base riddled with groundwater sampling wells and injection wells used for injecting cleanup solutions or extracting pollutants. Continue reading “Navy’s Cleanup Drawing Scrutiny”

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.

OU-2B thermal treatment — 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.

thermal treatment graphic — 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.