SAN FRANCISCO — The U.S. Environmental Protection is ordering a $60 million clean-up of rocket fuel-polluted groundwater at the Aerojet Superfund Site in Sacramento County, Calif., the latest phase of a long-term decontamination project at the site. The extent of toxic pollution at the site makes it one of the largest and most comprehensive Superfund groundwater cleanups in California.
A 27-square mile swath of groundwater underneath and around the former aerospace facility is polluted with several compounds, including very high levels of perchlorate — a main component of rocket fuel — and a known developmental toxin. Aerojet, under the direction of the EPA, will contain the underground plume to prevent it from spreading into nearby rivers and streams. Future plans will also treat groundwater within the site’s boundaries.

This site is one of many former aerospace facilities that requires site investigation, cleanup, and various other compliance-related focus.

Form more information, see the EPA website: www.epa.gov/region09/Aerojet

Perhaps most interestingly, 1,4-dioxane, 1,2,3-TCP, NDMA, and Nitrosamines now have notification limits, but do not have MCLs. These notification limits really only pertain to potable water suppliers, but the same values are likely to be the MCLs in the upcoming years.

This is worth keeping an eye on.

Ethylbenzene:
Residential Soil Gas on engineered fill – 1.1 µg/L
Residential Soil Gas on base soil – 0.42 µg/L
Industrial Soil Gas on engineered fill – 3.6 µg/L
Industrial Soil Gas on base soil – 1.4 µg/L

Perchlorate:
Residential Soil – 28 mg/Kg
Industrial Soil – 350 mg/Kg

There has been a significant amount of discussion regarding regulatory limits of perchlorate in drinking water. Now that there is an adopted standard for perchlorate in soil, I would expect a standard for drinking water and groundwater to follow shortly.

More updates to follow.

Please Contact Me if you are concerned that this may apply to you.

U.S. EPA to sample indoor air at Oakland homes, businesses near former plating shop

Release date: 07/23/2008

Contact Information: Wendy Chavez, 415/947-4248, chavez.wendy@epa.gov

High levels of VOCs found underground in Oakland

(San Francisco, Calif. — 07/23/08) – On Friday, the U.S. Environmental Protection Agency will begin testing the air inside several nearby homes, an adjacent business, and a day care center near the former Lane Metal Finishers site, where high levels of volatile organic compounds were found underground in Oakland, Calif.

Department of Toxic Substances Control scientists discovered elevated levels of VOCs in five samples taken at eight feet below the surface of the former metal plating site located at 30th Street & San Pablo Avenue. DTSC contacted the EPA to sample the indoor air to see if contaminants in the soil have migrated and are accumulating in nearby homes and businesses.

View Larger Map

“Because of the unknowns below the surface of the rest of the site, the EPA will sample the indoor air as a precautionary measure,” said Bret Moxley, the EPA’s on-scene coordinator. “The EPA and DTSC are working together to make sure that VOCs are not accumulating indoors, and if needed, will take the necessary steps until the situation is remedied.”

The underground samples showed very high levels of VOCs, particularly trichloroethylene (TCE), cis-dichloroethene, trans dichloroethene and vinyl chloride in the soil vapor. Soil vapor is in the spaces between the grains of sand or soil underground. Soil vapor can move through soil, but does not move as easily through clay and silt as it does in sandy soil. This site does have several clay layers in the soil which may have reduced the migration of the soil vapors.

Once under a home or other building, it is possible for vapors to come up through cracks in foundations and accumulate inside. If indoor VOC levels are high enough, it can create a health hazard for residents, especially children and pregnant women.

Soil, soil vapor and groundwater contamination at the Lane Metals facility is most likely the result of solvents used as degreasers during plating operations on the site dating back to the 1950s. The solvents are not uncommon at plating shop sites. DTSC has been overseeing the investigation of the site since June 2007.

By John Johnson Jr., Los Angeles Times Staff Writer
August 6, 2008

New soil chemistry tests by NASA’s Phoenix Mars lander have unexpectedly uncovered evidence of perchlorate, a highly reactive salt found naturally on Earth and used in a variety of products, including fertilizer, fireworks and rocket fuel, scientists said Tuesday.

The finding has surprised scientists evaluating results from Phoenix, but they denied that the presence of large amounts of the salt would render Mars uninhabitable.

“It might even be a positive” indicator for habitability, said Peter Smith, principal investigator on the Phoenix mission.

On Earth, perchlorate is found most abundantly in the surface soils of Chile’s Atacama Desert, which coincidentally has long served as a Martian stand-in for researchers trying to understand conditions on the Red Planet.

The 600-mile-long strip of land in Chile is about 50 times drier than Death Valley. Even so, it is not uninhabited. Microbes flourish there, and some life forms even feed on the perchlorate in the soil.

“This is an important piece in the puzzle” surrounding Mars and its ability to sustain life, Smith said at a media briefing in Tucson, where much of the Phoenix research is based at the University of Arizona. “In itself, it’s neither good nor bad for life,” he said.

Perchlorate was first detected several weeks ago with Phoenix’s onboard wet chemistry lab, which mixes water from Earth with Martian soils.

The scientific team held back the information while researchers tried to confirm the finding with a second onboard instrument, known as the thermal and evolved-gas analyzer, which can heat the soil up to 1,800 degrees Fahrenheit to determine its exact chemical composition.

Those tests remain incomplete, but NASA decided to publicize the perchlorate discovery Tuesday after word spread that the agency was hiding evidence that Mars was hostile to life.

The scientists Tuesday denied that they were being secretive, saying they simply wanted to consult with other scientists before publicizing the data.

Researchers said they were initially startled by the size of the chemical signal. Because it was so large, they at first discounted it, thinking the instrument had developed a problem.

Some scientists thought the device might even be picking up contamination from the rocket engines that carried Phoenix across 200 million miles of space from Earth to the vast, rolling northern plains of Mars.

But on Tuesday, the scientists tended to discount contamination because the craft’s descent engines use hydrazine, not chlorine. Also, no perchlorate was found when Phoenix calibrated the wet chemistry lab after its landing May 25 on the Red Planet.

The wet chemistry lab is a set of four beakers into which water is injected to mix with the soil. A collection of 26 sensors then samples the mixture to analyze its contents.

Because perchlorate is so soluble in water, it is rarely found in surface soils on Earth. Even though Phoenix is sitting atop a vast underground sheet of hard-as-concrete ice, it hasn’t rained on Mars in billions of years.

As well as confirming the wet chemistry finding with the TEGA instrument, the scientists are trying to understand the mechanism that could deposit such large amounts of perchlorate on the surface.

The only other chemistry done on Mars was by the twin Viking landers in the 1970s. They found possible evidence of peroxide, a very different compound.

Because Phoenix is stationary, it won’t be possible to determine how widespread these varieties of soils are. That must wait for the giant Mars Science Lab, scheduled for launch in 2009.

john.johnson@latimes.com

A transaction screen is a limited environmental assessment designed to identify readily apparent and potential environmental liabilities associated with a site or facility. All work is conducted in accordance with the ASTM E 1528-06: Standard Practice for Environmental Site Assessments: Transaction Screen Process. This ASTM standard was established by the ASTM Committee E-50 on Commercial Real Estate Transactions to provide landowners and purchasers with a basic understanding of the potential environmental concerns that may be associated with a particular parcel of real property. Exceptions to the ASTM standards are allowable to the extent that they are reasonable and that they are identified in the report.

A transaction screen can be described in short as a, “Phase I light” because it is a form of property due diligence, but is not as in-depth of an investigation as a full phase I. Transaction screens can be a very useful tool when an environmental investigation is required, but the property is not expected to be impacted, contaminated, or otherwise dirty.

From the late 1980s to 1997, a manufacturer of metal fasteners for the aerospace industry and military was located at the site.  These former operations are reported to have included the use of Aboveground Storage Tanks (ASTs) and petroleum solvents.  The former property owner also operated a waste storage area near the center of the southern portion of the site.  The site is currently occupied by various tenants that utilize the property for warehousing, distribution, and small-scale manufacturing.  

Several phases of soil, soil gas, and groundwater investigations have been performed at the site between 1998 and 2006.  The primary objective of subsurface investigations at the site was to provide analytical data that will identify the nature and extent of PCE in soil and groundwater beneath the site.  To help meet this objective, a total of twelve soil borings have been advanced at the site to help characterize PCE in soil.  Three soil gas probes were advanced at the site to help characterize PCE in soil gas.  Additionally, GeoTrans installed and sampled groundwater monitoring wells at the site in two locations to characterize PCE in groundwater.  

Based on the results of this current program and previous soils investigations at the Site, GeoTrans concluded that very low concentrations of PCE are present beneath the southern portion of the Site.  We worked with the Los Angeles Regional Water Quality Control Board and concluded that the presence of this constituent at the concentrations detected during our site investigations is unlikely to pose a significant threat to human health or the environment. Therefore, no further work is warranted at this time in regards to soil and groundwater at the site. 

Now, it’s time to get on with the investigation of the tank leak. Let’s assume that the depth to groundwater in this area is relatively shallow (<30′). Let’s also assume that the soils in the area are sandy or fine-grained (not cobbles or boulders). With these assumptions, we will be able to perform our investigation using a direct-push rig. This device is a truck mounted device that uses the weight of the truck and a hydraulic hammer to drive rods into the sub-surface allowing the operator to collect soil, soil gas, and groundwater samples.

We will collect a few soil samples, soil gas samples, and groundwater samples around the tank area, but there is a significant amount of setup work that needs to be done first. I’ll get into that in my next blog post.