Moffett Naval Air Station Moffett Field CA

Moffett Naval Air Station in California is a 1,500-acre site located in Moffett Field, California. Moffett Field is located 35 miles south of San Francisco and approximately 1 mile south of San Francisco Bay in Santa Clara County, California. It was purchased in 1931 for one dollar, according to records, and was commissioned in 1933 as a naval air station to support a “lighter-than-air” (LTA) program (“Moffett Federal Airfield” – GlobalSecurity.org 2012). In 1991, Moffett Field was recommended for closure under the Base Realignment and Closure (BRAC) process.  

During its peak operation, Moffett Field had 8,000 employees that consisted of 7,500 military personnel, 1,500 civilian workers, and 1,000 reservist personnel (“Moffett Federal Airfield” GlobalSecurity.org 2012).

Military activities at the site contaminated groundwater, soil and wetlands with volatile organic compounds (VOCs), polychlorinated biphenyls (PCBs) and pesticides. Cleanup activities are in various phases of completion. Operation and maintenance activities and monitoring are also ongoing.

The Navy and NASA have identified over 30 hazardous waste sites at the site. The long-term remedies included sediment and soil excavation, treatment and off-site disposal. Ongoing work is being conducted at eight of these sites. Groundwater in aquifers beneath the site is not used for drinking water. Groundwater in the area is, however, a potential future source of drinking water requiring groundwater cleanup standards to be set in place.

An average of 3,805 people live within a 1-mile radius of the installation, in around 1500 homes. Yet, the potential liability involved with hazardous materials in close proximity to a military base prevented homeowners from the surrounding community from obtaining home improvement loans (Diringer 1991).

Initial Actions:

Initial actions included closure of abandoned wells, source control measures, bioremediation of contaminated soil and carbon adsorption treatment of groundwater. These activities finished in 1996. A groundwater extraction and treatment system operated at the site until 1997, when it closed down to allow for operation of a regional system. At Site 29-Hanger 1, the Navy applied a specialized coating to the exterior surface of Hangar 1 to seal building materials in 2003.

The following is a comprehensive listing of final site remedies provided by the EPA Superfund, verbatim:

Operable Unit 1 – Landfill Sites 1 and 2: Site 1 was a 12-acre landfill that operated from the mid-1960s to late 1970s. Site 2 was a 1-acre landfill used between the 1940s and 1952. The long-term remedy included consolidation of Site 1 and Site 2 refuse and a multi-layer cap to contain the wastes.

Site 22 – Golf Course Landfill: The Navy operated this 11-acre landfill from 1950 to 1967. The long-term remedy included a biotic barrier made of gravel and cobblestone. The biotic barrier allows for future use as a golf course.

Site 25 – Eastern Diked Marsh and Stormwater Retention Pond: This site includes NASA’s 175-acre stormwater retention pond and the Eastern Diked Marsh, as well as about 52 acres owned by the Midpeninsula Regional Open Space District. The long-term remedy included restoring part of the area to a tidal marsh by excavating sediments, treating certain areas with lead and zinc contamination, and disposing of the sediments off site.

Site 26 – East-Side Aquifer Treatment System (EATS) Area: The EATS area is near Hangar 3, where activities contaminated groundwater with VOCs. The long-term remedy included a groundwater extraction and treatment system of five extraction wells and an air stripper with carbon treatment. The Moffett Field storm drain system would receive the treated water. In 2014, the long-term remedy was changed to include enhanced treatment of contaminated groundwater in three areas and monitored natural attenuation for the rest of the plume area.

Site 27 – Northern Channel: The site consists of the Northern Channel and ditches that drain into the channel. The long-term remedy included the removal of contaminated sediment in the channel and ditches to protect the site’s ecosystem.

Site 28 – West-Side Aquifers Treatment System (WATS) Area: This site consists of groundwater contamination on the east side of the runways, possibly contaminated by a former dry cleaning facility, former fuel storage and wash rack facilities, and former manufacturing facilities. In 1994, the Navy removed soil contaminants by demolishing a building and removing a tank and sumps.

The long-term remedy included a groundwater extraction and treatment system. This site is part of the Middlefield/Ellis/Whisman (MEW) Study Area. The MEW Study Area Record of Decision addresses this area. The remedy included in-place vapor extraction and treatment to treat contaminated soils, extraction and treatment to treat contaminated groundwater, identification and sealing of potentially contaminated wells, maintaining inward and upward hydraulic gradients through pumping and treatment inside slurry walls, and regular monitoring of the slurry wall system.

Site 29 – Hangar 1: The Navy constructed Hangar 1 in 1932 to house the giant airship U.S.S. Macon. Building materials at the hangar are contaminated with PCBs, asbestos, lead and zinc. The Navy recommended removing the siding and coating the structural steel frame of Hangar 1 in 2007. The Navy signed an action memorandum confirming the action in 2009.

Area of Investigation (AOI) 14 – Former Soil Fill Area: The interim remedy consisted of the construction of silt fencing around the perimeter of the 8-acre area to prevent the erosion of contaminated soils into nearby Site 25. The final remedy requires the excavation and disposal of contaminated soils.

No Further Action Sites: EPA selected “no further action” as the remedy for six sites because they did not present a potential threat to human health and the environment.

Petroleum Sites: The California Leaking Underground Storage Tank Program is addressing the petroleum sites.

Cleanup Progress:

OU1 – Landfill Sites 1 and 2: At Site 1, construction of the multi-layer landfill cap finished in 1998. Long-term maintenance of the cap and monitoring of landfill gas and groundwater began in 1999. EPA and the Water Board approved the closure of Site 2 in 2003 because site conditions qualified the area for unrestricted use. The most recent five-year review concluded that response actions at the site are in accordance with the remedy selected by EPA and that the remedy continues to be protective of human health and the environment in the short term. Continued protectiveness of the remedy requires incorporation of institutional controls in NASA’s master plan and evaluation of the effectiveness of the burrowing mammal abatement plan.

Site 22 – Golf Course Landfill: Construction of the biotic barrier finished in 2003. Regular maintenance and long-term monitoring of groundwater and landfill gas is ongoing. The most recent five-year review concluded that response actions at the site are in accordance with the remedy selected by EPA and that the remedy continues to be protective of human health and the environment in the short term. Continued protectiveness of the remedy requires incorporation of institutional controls in NASA’s master plan.

Site 25 – Eastern Dike Marsh and Stormwater Retention Pond: Restoration activities and cleanup finished in 2013.

Site 26 – EATS Area: The groundwater extraction and treatment system in the original remedy began operating in 1999. In 2019, consistent with the new remedy, treatment mixtures were injected into contaminated groundwater in three areas. Monitoring will determine the performance of the treatment and the natural degradation process in decreasing levels of contamination in groundwater.

Site 27 – Northern Channel: Active excavation of contaminated soils and sediments finished in 2007. Site restoration activities finished in 2012.

Site 28 – West-Side Aquifers Treatment System (WATS) Area: The WATS began operating in 1998. The most recent five-year review concluded that response actions at the site are in accordance with the remedy selected by EPA and that the remedy continues to be protective of human health and the environment in the short term. Continued protectiveness of the remedy requires incorporating results of the vapor intrusion pathway study into site construction permit requirements, continuation of the pilot test and evaluation of need for institutional controls.

Site 29 – Hangar 1: The Navy completed removal of the siding and coated the structural steel frame in 2012. In 2015, NASA assumed responsibility for long-term monitoring and maintenance of Hangar 1. NASA has evaluated options for removing the coating and contaminated paints on the steel frame and is planning to proceed with this work.

Area of Investigation (AOI) 14 – Former Soil Fill Area: Construction of the silt fencing around the site was completed in 2014. The excavation and disposal of contaminated soils and removal of the silt fence was completed in 2019.

Risks and pathways addressed by the cleanup include health risks to animals and people from inhaling, ingesting or touching contaminants in air, soil and groundwater.

Full List of Contaminants of Concern for this site:

 

 

 

Moffett Field Today

On some of the very same land used by Moffett Field, today, Google and NASA campuses sit on this hazardous waste site with contaminated soil. TCE from nearby plants also migrated through the ground toward NASA’s nearby Ames Research Center.

Contaminated groundwater, however, isn’t the only source of TCE exposure. As seen with other bases, soil vapor intrusion builds up underground plumes of the chemical, often migrating to the surface and escaping into the air in concentrated areas (especially building foundations), where it can be equally dangerous to inhale. The EPA found that air samples at the Google complex in Mountain View showed unsafe levels of TCE from November 2012 to January 2013.

The area continues to undergo monitoring and remediation.

Site Contacts

Community Involvement Coordinator:

Jackie Lane
(415) 972-3236
Remedial Project Manager:

Alana Lee
(415) 972-3141
Yvonne Fong
(415) 947-4117
Lucrina Jones
(415) 972-3006

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