Cleanup staff

Santa Susana: A Comprehensive Cleanup

Cleanup Process

Solvents containing volatile organic compounds were previously used to clean rocket engine test equipment to ensure the safety of workers at the Santa Susana Field Laboratory. Following approved practices at the time, these solvents were often disposed onsite, seeping into soil and groundwater. The primary chemicals found in the groundwater under the site are trichloroethylene (TCE) and 1,2-dichloroethylene (1,2-DCE). Low-level radioactive contamination resulting from energy research operations remains in soil on about one percent of the property.

Santa Susana is divided into four administrative areas that reflect its past operations, current ownership and cleanup responsibility. Boeing owns most of the property; the U.S. government owns a portion, administered by NASA and the U.S. Department of Energy leased portions from Boeing. In 2007, all three parties signed a comprehensive cleanup agreement with the California Department of Toxic Substances Control (DTSC).

Under this Consent Order, Boeing has committed to performing a risk-based cleanup of soil and groundwater contaminated by chemicals, applying standards that are in-line with other cleanup sites throughout California. Boeing remains committed to completing a cleanup that fully protects both human health and the environment, and is consistent with Santa Susana's future use as open space habitat.

DTSC experts have confirmed that cleanup under the Consent Order will safeguard human health. Also, numerous studies conclude that there is no evidence that past operations at the Santa Susana Field Laboratory have affected the health of the local community.

Area IV of Santa Susana has localized areas with radioactive contamination above naturally-occurring levels, which is the responsibility of the Department of Energy. In 2012, the U.S. Environmental Protection Agency completed an extensive radiation survey and found that low levels of residual contamination from past nuclear energy research affects approximately 40 acres of this portion of the site. The results demonstrate that previous remediation efforts have been effective in eliminating the majority of legacy contamination.

Making Progress

Efforts to remove contamination from the site began three decades ago and soil cleanup is slated for 2019. Thus far, Boeing's environmental studies and interim cleanup measures have accomplished:

  • Removal or treatment of nearly 45,000 cubic yards of soil, which is enough to fill more than 2,800 dump trucks
  • Analyses of 38,000+ soil, bedrock and groundwater samples
  • Restoration of 900 acres of land
  • Drilling 260 groundwater monitoring and extraction wells
  • Installation of a groundwater treatment system
  • Construction of two state-of-the-art stormwater treatment systems to meet water quality standards
  • Creation of a biofiltration system to naturally treat stormwater

In addition, more than 300 structures have been decommissioned and demolished in accordance with state and federal standards.

Boeing has received commendations from the California Stormwater Quality Association and the Wildlife Habitat Council for its cleanup and restoration efforts. As more people learn of Santa Susana’s natural and cultural resources and its historical significance in protecting national security, the site is becoming a magnet for environmental research and restoration by universities, environmental groups and conservation organizations.

Visit the DTSC website for more cleanup news and information, including technical reports.

Cleanup staff Boeing has staff onsite who are dedicated to investigation and cleanup activities with oversight from the Department of Toxic Substances Control.

Soil Cleanup

Soil cleanup equipment Boeing has begun to address soil contamination by removing or treating 45,000 cubic yards of soil, which is enough to fill more than 2,800 dump trucks.

With oversight from the DTSC, Boeing is currently completing the investigation phase of its soil cleanup program. The goals of the program are to characterize the nature and extent of chemical contamination, evaluate potential risks to people and the environment, and gather data to support the DTSC cleanup plan.

Boeing has analyzed more than 21,000 soil samples for numerous chemical constituents at Santa Susana, and completed more than 10 interim cleanups. This amounts to the removal of nearly 45,000 cubic yards of contaminated soil, as well as in situ, “in place,” bioremediation.

Groundwater Cleanup

With oversight from the DTSC, Boeing is conducting an investigation of groundwater under and near the Santa Susana site. The goals of the program are to characterize the nature and extent of chemical contamination, evaluate potential risks to people and the environment, and gather data to support the DTSC site-wide cleanup plan.

The investigation entails analyzing groundwater from 260 on- and off-site wells, mapping the geology of Simi Hills, and identifying and sampling seeps and springs. An extraction treatment system treats groundwater pumped from wells throughout the site. The system is capable of treating approximately 100 gallons of water per minute and removes chemicals like trichloroethylene (TCE) and 1,2-dichloroethylene (1,2-DCE).

Under the direction of the Groundwater Advisory Panel, several new techniques have been developed and employed at Santa Susana to provide a detailed examination of the fractured bedrock and deep groundwater. This includes analyzing more than 8,400 rock samples for chemicals, as well as installing measuring devices in numerous wells to study the distribution of the chemical contamination.

There is only one location, in the northeast area of the site, where off-site groundwater appears to be affected. A comprehensive evaluation of the property surrounding the Santa Susana site reveals no traces of chemicals in groundwater emerging above-ground through seeps and springs.

Boeing is conducting a year-long study of possible groundwater cleanup methods using in-situ chemical oxidation. This technology involves injection of a potassium permanganate solution into contaminated groundwater at the northeast corner of the site.

Cleanup staff A team installs groundwater monitoring wells as part of Boeing’s seeps and springs investigation.

Stormwater Management

Cleanup staff Boeing designed and constructed two advanced treatment systems to improve stormwater quality at Santa Susana.

Stormwater at Santa Susana is regulated under a permit issued by the Los Angeles Regional Water Quality Control Board.

Stormwater follows the natural topography through a series of channels and ponds until it leaves the Santa Susana site. Certain points along these natural pathways, called “outfalls,” are selected by the Regional Board as locations where monitoring and sampling should be performed to measure water quality.

Sixteen outfalls at Santa Susana are monitored under the guidelines of a National Pollutant Discharge Elimination System permit. Boeing collects stormwater samples to be analyzed for a variety of pollutants when water flow is observed in the outfalls.

For the past five years, 2011 through 2014, Boeing has achieved a 97 percent compliance rate with extremely stringent stormwater pollution limits that, in many cases, are lower than what is required for the water that people drink. In an effort to meet these limits, Boeing has instituted a rigorous monitoring program and is making progress in improving the quality of stormwater runoff that leaves the site by:

  • Investing in two state-of-the-art stormwater treatment systems that can treat 2.5 million gallons during rain events.
  • Installing a biofilter that treats stormwater using natural processes.
  • Excavating 25,000 cubic yards of contaminated soil.

The Santa Susana Stormwater Expert Panel is an independent committee of five internationally recognized experts who have been providing guidance to Boeing and the Regional Board since 2008. Their recommendations have included best management practices and measures that include biofiltration, culvert modifications, soil and pavement removal, erosion controls and channel restoration.