Federal Facility and Superfund Sites Where Action Has Been Taken to Address Perchlorate Contamination

As of August 4, 2004

Alabama
California
Iowa
Maryland
Massachusetts
Nevada
Texas

ALABAMA

Redstone Army Arsenal - Huntsville, AL (NPL)
Established in 1941, Redstone Army Arsenal is an active U.S. Army facility occupying about 38,300 acres in Madison County, Alabama. Between 1942 and 1945, the Army produced conventional and chemical munitions for World War II, including perchlorate-based colored smoke munitions. Subsequently, the Thiokol Chemical Corporation and the Rohm and Haas Company began operations at Redstone in 1949 in support of the Army, Navy, Air Force, and NASA aerospace programs. The Raytheon Company began solid propellant research and development operations in the former Rohm and Haas area in 1974. The manufacture of solid propellants at Redstone ceased in 1996 when Thiokol ceased operations at this National Priorities List (NPL) facility.

The maximum concentration of perchlorate detected to date in shallow groundwater is 19,000 parts per billion (ppb). A chlorinated solvent and perchlorate plume has migrated beyond the east boundary of the facility; however, residents in the adjacent subdivisions utilize a public water supply and are not at risk from the contamination. In 2000, EPA, the Alabama Department of Environmental Management (ADEM), and Redstone agreed to shut down a groundwater treatment system for chlorinated solvents that was inadvertently discharging untreated perchlorate to the Tennessee River. Perchlorate has also been detected in soils beneath storage pads and in surface water along Redstone's eastern boundary. Redstone plans to complete environmental media characterization for perchlorate at the higher priority sites in Fiscal Year (FY) 2004 and conduct perchlorate treatability studies in FY 2004 and FY 2005 in support of remedy selection.

CALIFORNIA

Aerojet General Corp. Superfund Site - Rancho Cordova, CA (NPL)
The Aerojet Superfund site is a 5,900-acre rocket motor manufacturing and testing site fifteen miles east of Sacramento, California. Soils and groundwater at the site are contaminated with volatile organic compounds such as trichloroethylene (TCE) and rocket propulsion components including perchlorate and n-nitrosodimethamine (NDMA). In the early 1990s, detection of part-per-million levels of perchlorate in a drinking water supply aquifer led EPA's Superfund team to request the country's first evaluation of perchlorate's toxicity. The first large-scale perchlorate treatment process in the U.S. was developed and implemented at the Aerojet site in 1998. This biological system treats more than seven million gallons of contaminated groundwater each day and reduces blended perchlorate concentrations from 2,500 parts per billion (ppb) to less than 4 ppb. In the July 2001 Record of Decision (ROD) for the first of multiple operable units (OUs) for the Aerojet site, EPA set an enforceable site-specific cleanup standard for perchlorate at four ppb. EPA's August 2002 Unilateral Administrative Order (UAO) requires Aerojet-General Corp. to design, build, and operate a groundwater extraction and treatment system to contain and clean up groundwater contamination in the western portion of the Aerojet site. The order also requires Aerojet to provide needed replacement water for wells lost due to contamination.

Edwards AFB, CA (NPL)
Edwards Air Force Base (AFB) is a 301,000 acre military base located in the Antelope Valley region in Southern California. Edwards AFB was placed on the National Priorities List (NPL) in 1990 and entered into a Federal Facility Agreement (FFA) with the US EPA, the California Department of Toxic Substances Control (DTSC), and the California Regional Water Quality Board (RWQCB) in 1992. Perchlorate contamination at Edwards AFB resulted from years of solid-fuel propellant development and rocket testing. This solid propellant testing created several groundwater plumes on Edwards AFB in Operable Units (OUs) 4, 5, 6, 9, and 10. The maximum concentration of perchlorate detected at Edwards AFB was 160,000 parts per billion (ppb) in OU 5. An ion exchange treatability study has been implemented at Site 285 in OU5. This treatability study was initiated in May 2003 and is expected to run for two years with the hope that this study will not only demonstrate the technology's effectiveness, but also achieve cleanup to levels safe to human health and the environment. Since May 2003, 2.6 million gallons of groundwater have been treated and 7 pounds of perchlorate have been removed. This OU is currently in the Remedial Investigation/Feasibility Study (RI/FS) phase with a Record of Decision (ROD) scheduled for 2008. The Air Force is responsible for all costs associated with the investigation and cleanup of the perchlorate.

Lawrence Livermore National Laboratory, CA (NPL)
The 11-acre Lawrence Livermore National Laboratory (LLNL) site 300 has been operated by the University of California for the U.S. Department of Energy (DOE) primarily as a high-explosives and materials testing site in support of nuclear weapons research. This site was named an NPL (Superfund) site in 1990. Approximately 350 people who work in the area and adjacent ranch houses draw drinking water from the aquifer in the immediate vicinity. Nitrate, high explosive compounds and perchlorate are among the groundwater contaminants that resulted from the laboratory's activities since its inception in 1952.

DOE scientists developed an innovative constructed wetlands system to biologically degrade nitrate under relatively low-flow conditions (5 to 10 gallons per minute) at remote locations throughout the site. Both nitrate and perchlorate are degraded to harmless elements by related microbial populations that are supported by the wetlands, which are contained in tanks that can be relocated as necessary. There are currently two treatment facilities with wetlands, used in conjunction with ion exchange, and one more facility is planned. The contained wetlands have reduced perchlorate concentrations from 10 to 20 micrograms/L to less than 4 micrograms/L. Nitrate concentrations have been reduced from 90+ mg/L to below 45 mg/L (the discharge requirement).

NASA Jet Propulsion Laboratory, CA (NPL)
NASA Jet Propulsion Laboratory (JPL) is a space science lab covering 176 acres in Pasadena. JPL was placed on the NPL in 1992 after several solvents were found in downgradient drinking water wells. Perchlorate was first discovered at the same downgradient wells in 1996. Subsequent on-site and off-site investigations have identified an on-site source area with levels of perchlorate in groundwater around 1,500 parts per billion (ppb). The off-site portion of the plume has levels up to 200 ppb, and the plume has caused seven water supply wells to be taken out of service. In July 2004, NASA paid for the installation of an ion exchange and carbon treatment system at the Lincoln Avenue Water Company. The system is currently treating approximately three million gallons per day. The water is then distributed for public consumption after treatment. An on-site treatment system is under construction. This system will use a fluidized bed biological reactor to treat approximately 125 gallons per minute which will be pumped from the source area. The treated water will then be injected back into the aquifer. Negotiations and design are currently underway to install an ion exchange system on wells owned by the City of Pasadena. The plume should be contained and treatment systems installed on affected city wells by mid-2005.

Olin Flare Facility - Morgan Hill, CA
Perchlorate contamination beneath a former flare manufacturing plant was first discovered in 2000, several years after the plant had closed. The plant had used potassium perchlorate as one of the ingredients during 40 years of operation. By late 2003, the state of California and the Santa Clara Valley Water District had confirmed a groundwater plume currently extending over nine miles through residential and agricultural communities. The Regional Water Quality Control Board in conjunction with the Santa Clara Valley Water District has a major outreach effort that has received extensive press and community response. An extensive well testing program is underway for approximately 1,200 residential, municipal, and agricultural wells in the area. Large ion exchange treatment units are operating for three public water supply systems in which seven municipal wells are impacted, and bottled water is being supplied to nearly 800 households with private wells by the potentially responsible parties (PRPs), Olin Corporation and Standard Fuse Incorporated. The Regional Water Quality Control board is overseeing PRP cleanup efforts.

Rialto-Colton Area, CA
In the Rialto-Colton area in San Bernadino, California, perchlorate has been detected in 20 water supply wells at concentrations above the California action level of four parts per billion (ppb). The loss of these wells created a serious water supply shortage in the summer of 2003 for the four affected water companies. EPA has issued a Unilateral Administrative Order (UAO) to two former operators at the site and the State of California Regional Water Quality Control Board has issued investigation orders to 19 parties suspected of testing, manufacturing, storing, or disposing of perchlorate-containing materials in the area. The state has already provided $6 million to help the four affected water companies purchase water treatment equipment. One of the Potentially Responsible Parties (PRPs) has provided an additional $4 million. As of September 2003, the four water utilities have installed four ion exchange systems and by the end of the year four more systems are expected to go online, allowing treatment of more than 20 million gallons per day of perchlorate-contaminated groundwater.

San Gabriel Valley, CA Superfund Sites (NPL)
At the San Gabriel Valley Superfund sites, perchlorate has been detected in at least 23 water supply wells. Most of the contaminated wells are located in the Azusa/Baldwin Park area, where the testing and manufacture of solid-fuel rockets in the 1940s and 1950s is believed to be the primary source of the contamination. The first perchlorate treatment system was completed in March 2001, making use of ion exchange technology. The treatment system is cleaning up the groundwater and supplying drinking water to approximately 9,000 San Gabriel Valley residents. Two additional perchlorate treatment systems are scheduled for completion in late 2003. When the fourth and last system is completed in late 2004 or early 2005, the four perchlorate treatment systems, estimated to cost more than $17 million to install and roughly $5 million per year to operate, will supply drinking water to more than 100,000 San Gabriel Valley residents. Over the next 15 years, it is expected that more than $200 million will be spent on cleanup of perchlorate and other groundwater contaminants at the Baldwin Park site alone. The costs are being paid by a group of Potentially Responsible Parties (PRPs) and federal appropriations earmarked for San Gabriel Valley cleanup.

Stringfellow, CA Superfund Site (NPL)
The Stringfellow Superfund site is located near the community of Glen Avon, in Riverside County, California. From 1955 until 1972, the 17-acre Stringfellow site was operated as a state-permitted hazardous waste disposal facility. More than 35 million gallons of industrial waste, primarily from metal finishing, electroplating, and pesticide production were deposited in various pits at the site. Cleanup efforts, lead by California Department of Toxic Substances Control (DTSC), have focused on controlling the waste sources and capturing the contaminated groundwater plume containing site-related contaminants. In May 2001, California officials detected perchlorate in groundwater throughout the site, including parts of the aquifer beyond the existing plume capture area. Results indicate the maximum perchlorate concentration in groundwater to be 87,000 ppb at the source. Approximately 30 private wells have been affected by perchlorate ranging in concentration from 2.1 to 37 ppb. DTSC recently hired a contractor and finalized the work plan to conduct a remedial investigation and feasibility study to respond to the perchlorate contamination. The Stringfellow Advisory Committee met to formally kick off the effort in August 2004.

IOWA

Hills Iowa Perchlorate Site - Hills, IA
In May of 2003, sampling conducted in Hills, Iowa confirmed detections of perchlorate above four parts per billion (ppb) in 21 residential drinking wells as well as one commercial business drinking water well that supplies approximately 115 employees. As an interim action, bottled water is being supplied to those persons whose drinking water exceeds 18 ppb of perchlorate, and to certain sub-populations, including pregnant women and women of child-bearing age, whose drinking water is between 4 and 18 ppb of perchlorate and where there are additional aggravating high risk factors, until a more permanent remedy for the site is determined. Currently the source of the perchlorate is unknown and another round of sampling is being planned in order to determine the extent of the perchlorate contamination in Hills.

MARYLAND

Aberdeen Proving Grounds (APG), MD (NPL)
The Aberdeen Area of the Aberdeen Proving Grounds (APG) is comprised of 17,000 acres. Since 1917 APG was used for the development and testing of chemical agent munitions. APG has large areas of land and water and numerous buildings that are contaminated or potentially contaminated with a variety of chemicals. Approximately 36,000 people live within three miles of the site. Tests of drinking water at APG have detected perchlorate in four production wells and in the finished water supply for the city of Aberdeen. Perchlorate levels detected ranged from 1.0 - 2.1 parts per billion (ppb) in production wells and from 0.2 - 1.0 ppb in supplied drinking water. Over the past two years, the average perchlorate in finished water has been about 0.6 ppb. As a result of the perchlorate contamination, the Maryland Department of the Environment (DEP) sent a letter to the city of Aberdeen recommending that they take actions to protect the public if the finished water exceeds one ppb. Although the finished water perchlorate concentrations are at levels less than one ppb, monitoring well samples show a groundwater plume approximately 4,000 feet long and 1,000 feet wide ranging from 4 to 10 ppb. Geoprobe samples have shown somewhat higher results and localized pockets of contamination of up to 50 ppb. One isolated geoprobe sample taken directly below a surface source showed a level of perchlorate of 3,500 ppb in ground water. However, this anomalous detection has been discounted, as a result of further intensive study and resampling.

Despite several meetings between EPA Region 3 and Army staff, no agreement could be made on an EPA proposed interim remedial action that could reduce the amount of perchlorate moving toward the city of Aberdeen's production wells. The Army and the city of Aberdeen expressed concern that the proposed interim action would further reduce the city's water supply. The city already currently purchases large quantities of water from the county. Currently, groundwater modeling is being conducted in order to assess the impact of various remedy configurations on contamination removal and production well yields. The Region and the state have written letters to the Army requesting remediation of soil hotspots (perchlorate in the range of 10 to 15 parts per million (ppm)), but these requests were ultimately rejected. Region 3 is currently awaiting the results of the National Academy of Sciences' (NAS) review of EPA's draft perchlorate health risk assessment in order to determine the next steps. Meanwhile, Region 3 continues to fine-tune the groundwater model so as to obtain a better understanding of the aquifer. Independently of EPA, MDE, and the Army, the city of Aberdeen is conducting pilot tests using an ion exchange resin, and may install a treatment system on the Aberdeen water supply.

MASSACHUSETTS

Massachusetts Military Reservation (MMR) Cape Cod, MA (NPL)
MMR is a 22,000-acre base comprised of the Impact and Training Areas and the Otis Air Force Base. The site overlies the Upper Cape Cod sole source aquifer. The southern portion of MMR (Otis AFB) was placed on the National Priorities List (NPL) in 1989. Cleanup of this portion of the base continues under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). For the Impact and Training Areas, routine training (e.g., firing of artillery, mortars, and open detonation of explosives) is the primary source of contamination. As a result, several billion gallons of groundwater contaminated with explosives, perchlorate, and other chemicals are emanating from numerous source areas. A 1997 Safe Drinking Water Act (SDWA) order halted live training activities pending completion of investigations for the training area. Other SDWA orders were issued requiring the implementation of rapid response actions, completion of feasibility studies and remedial designs, and implementation of remedial actions among other things. Rapid response actions for soil and groundwater have been completed and/or are being planned, while remedial plans are progressing for the larger, more complex sites.

Perchlorate has been detected both on and off MMR property. Low levels (below one part per billion (ppb)) of perchlorate have been detected in public supply wells within the town of Bourne's Monument Beach well field to the west of MMR. This well field contains four pumping wells that previously provided 70% of the town's drinking water. The Bourne Water District continues to keep two of the four wells offline. The Massachusetts Department of Environmental Protection (DEP) issued an advisory to the town of Bourne stating that women, infants, children, and other sensitive sub-populations should not drink water that contains perchlorate above one ppb. In addition, several residential wells and a community supply well northwest of the base have been identified as containing perchlorate. The maximum detection in the wells northwest of MMR is 1.8 ppb in one of the residential wells. This detection prompted the DEP to issue a Notice of Responsibility (NOR) to the National Guard Bureau (NGB)/Army requiring that they either provide the residence with bottled water or take other measures to mitigate the exposure pathway. The NGB/Army indicated that there was no legal mechanism for them to respond to the NOR. Thus, the Massachusetts DEP is providing bottled water to the residents. One-hundred-forty (140) ppb of perchlorate was recently detected in a newly installed monitoring well in the southeast range area of the base. This detection is within the zone of contribution of a drinking water supply well recently installed on MMR to provide replacement water to the surrounding communities that have had wells or well fields closed due to contamination emanating from MMR.

NEVADA

Tronox (formerly Kerr McGee Chemical Company) - Henderson, NV
Perchlorate contaminated ground water from Henderson, Nevada threatens the drinking water supply of 15 to 20 million people whose drinking water supplies originate from the lower Colorado River system. The contamination affects communities and Tribal nations in Arizona, southern California and southern Nevada. The contamination originates from the Kerr McGee/Tronox plant in Henderson, Nevada where prior owners/operators produced perchlorate (a solid rocket fuel ingredient) beginning in the early 1950s. Kerr McGee acquired the property in 1967 and continued perchlorate production until 1998. In November 2005 Kerr McGee "spun-off" its chemical operations into a separate company known as Tronox. Since the "discovery" of the perchlorate problem in 1997 when a more sensitive test method was developed, US EPA and the Nevada Division of Environmental Protection (NDEP) have been working with Kerr McGee/Tronox to ensure that perchlorate releases to Las Vegas Wash and Lake Mead are reduced as effectively and as quickly as possible. The control strategy adopted by Kerr McGee/Tronox has three goals: 1) capture and treat the most concentrated perchlorate at its source on Tronox property; 2) intercept and treat the contamination near the Las Vegas Wash to reduce impacts on the Wash and on Lake Mead as quickly as possible; and 3) extract and treat perchlorate from wells installed at a site midway between the Tronox plant and the Wash where a narrow subsurface channel allows effective and efficient capture of ground water. The captured ground water and surface water is treated in fluidized bed reactors (FBRs) (biologically based waste water treatment systems) to remove more than 99.99% of the perchlorate. Treatment plant discharges are regulated under the National Pollutant Discharge Elimination System (NPDES) program and must comply with the 18 ppb perchlorate limit in the NPDES permit issued by NDEP.

Initial control efforts began in 1999 at two of the three capture locations. The three location control strategy was fully implemented beginning in October 2002 when the midpoint capture wells became fully operational. The complete system captures 1700 to 2000 pounds per day of perchlorate before it reaches Las Vegas Wash. As of December 2005 the Tronox control systems have captured more than 3.6 million pounds (1800 tons) of perchlorate. To date the controls have reduced perchlorate releases to Las Vegas Wash from about 900 to 1000 pounds per day before controls to about 100 to 150 pounds per day, a reduction of about 85%. Further decreases to less than 100 pounds per day may occur in 2006.

As a result of these control efforts, perchlorate concentrations in Lake Mead and the lower Colorado River have declined significantly and are expected to decline further in 2006. Annual average concentrations at the Las Vegas drinking water supply intake in Lake Mead declined 70% between 2000 and 2005 (from 13.1 ppb to 3.8 ppb); the 2006 annual average could be less than 3.0 ppb. Annual average concentrations in the Metropolitan Water District (MWD) Colorado River Aqueduct intake at Lake Havasu on the Lower Colorado River have declined about 50% between 2000 and 2005 (from 6.4 ppb to less than 4 ppb); in 2005 eleven of the twelve monthly samples were non-detect (method detection limit was 4 ppb until October 2005; in November 2005 the MDL was reduced to 2 ppb). In 2005 all twelve monthly samples were less than 4 ppb. The annual average perchlorate concentration at Willow Beach on the Colorado River below Hoover Dam has declined more than 60% from 6.5 ppb in 2000 to 2.4 ppb in 2005. For comparison purposes the California Public Health Goal (PHG) for perchlorate is 6 ppb.

TEXAS

Longhorn Army Ammunition Plant Karnak, TX (NPL)
The Longhorn Army Ammunition Plant (LHAAP) is an 8,493-acre facility that operated from 1942 to 1997. Site operations included loading, assembling, and packing pyrotechnic and signal ammunition; manufacturing solid rocket motors; and demilitarization of rockets pursuant to a treaty with the former Soviet Union. The LHAAP was designated a National Priorities List (NPL) site in 1990 and has been identified as being "excess" to the Army mission. Soils and groundwater at the site are contaminated with volatile organic compounds (VOCs) such as trichloroethylene (TCE) and methylene chloride and rocket propulsion components including perchlorate. Surface water runoff from the site enters Caddo Lake, a public drinking water source for seven public water supply systems in the state of Louisiana. In February 2001, a perchlorate treatment unit was added to the site's groundwater treatment plant and has been successfully treating up to 50 gallons per minute of groundwater containing perchlorate up to 28,000 parts per billion (PPB) to levels less than 4 ppb. Numerous perchlorate field pilot studies have taken place and are ongoing at the site including an in-situ bioremediation of perchlorate and chlorinated solvents in groundwater study, a phytoremediation of perchlorate field demonstration, and an in-situ bioremediation of perchlorate-contaminated soils study.

Naval Weapons Industrial Reserve Plant (NWIRP) McGregor, Texas
This 9,700-acre Navy, Government Owned/Contractor Operated (GOCO) facility manufactured solid propellant rocket motors from 1978 to 1995. The city of McGregor is a willing recipient of this facility for the creation of an industrial park. Perchlorate is the main contaminant of concern (COC) in the surface water, groundwater, soils, and sediments. Other COCs are volatile organic compounds (VOCs), semivolatile organic compounds (SVOCs), metals, polychlorinated biphenyls (PCBs), and explosives. Investigation and remediation began in 1998, and to date, 6,000 acres have been transferred to the city. Remediation systems consists of Bio-borings and Bio-Reactor Trenches which use such media such as gravel, mushroom compost, and wood chips soaked in soy bean oil. Another system uses a groundwater recovery trench in conjunction with a Fluidized Bed Biological Reactor. With the Fluidized Bed Reactor processing between 35 and 300 gallons per minute (gpm) (GPM level is dependent upon whether it is the wet or dry season), the average concentration of perchlorate prior to treatment is 2,310 parts per billion (ppb) with the treated water concentrations being below 4 ppb (Non Detect). To date, 117,000,000 gallons of water have been treated and approximately 2,500 pounds of perchlorate has been removed at an average rate of 1 pound per 47,000 gallons of water. There is offsite migration of perchlorate in groundwater, concentrations are declining due to dilution, it is persistent in sediments, and regular sampling confirms that no threat exists to two very large municipal raw water supplies. The Bosque/Leon Rivers Watershed Perchlorate Study has been completed, and the final report is available on the U.S. Army Corps of Engineers web site at www.swf.usace.army.mil/ppmd/Perchlorate/index.html. The goal of this assessment was to evaluate potential human and environmental exposure to perchlorate associated with NWIRP activities in the Lake Belton and Lake Waco area.