SAN GABRIEL VALLEY (AREA 2) Baldwin Park
EPA #: CAD980818512
State: California(CA)
County: Los Angeles
City: Azusa, Baldwin Park, Irwindale, West Covina, La Puente, Industry
Congressional District: 31
Other Names:
Bulletin Board
The 2008 Annual Performance Evaluation Report, prepared in April 2009, is available in the "Technical Documents" section below. The report discusses the status of the cleanup, and provides a series of figures depicting the extent of groundwater contamination.
Description and History
NPL Listing History
NPL Status: Final
Proposed Date: 09/08/1983
Final Date: 05/08/1984
Deleted Date:
The San Gabriel Valley Area 2 Superfund Site is one of four Superfund sites in the San Gabriel Valley. The sites address multiple areas of contamination in the San Gabriel Basin aquifer, a critical source of drinking water for water-scarce Southern California. The Superfund sites include areas of soil and groundwater contamination underlying portions of the cities of Alhambra, Arcadia, Azusa, Baldwin Park, Industry, Irwindale, El Monte, La Puente, Monrovia, Rosemead, South El Monte, and West Covina. The San Gabriel Valley covers approximately 170 square miles.
Groundwater contamination was first detected in the San Gabriel Valley in 1979. Following this discovery, the California Department of Public Health (CDPH, formerly the Department of Health Services) analyzed water samples collected from water supply wells throughout the Valley to assess the extent of contamination. By 1984, 59 wells were found to be contaminated with volatile organic compounds (VOCs). In the late 1990s, perchlorate and other newly discovered contaminants were detected in the additional water supply and groundwater monitoring wells.
Despite the widespread extent of contamination, the San Gabriel Basin aquifer continues to provide approximately 90 percent of the domestic water supply for the Valley's one and one-half million residents. Water utilities in the area have continued to provide their customers with clean water by blending contaminated water with clean water to meet drinking water standards, obtaining water from neighboring utilities, and installing wellhead treatment systems. EPA's Superfund projects are providing additional water supplies, by providing treated groundwater to area water utilities for local use.
EPA's efforts at the sites began in the mid-1980s with studies needed to understand the sources, nature and extent of soil and groundwater contamination. In the 1980s and early 1990s, EPA also developed a basin-wide plan to set cleanup priorities, and led State and Federal efforts to develop the institutional framework necessary to address the contamination.
In the early 1990s, EPA divided the San Gabriel Valley into eight project areas, including the Baldwin Park area. In 1994, EPA adopted the cleanup plan for the Baldwin Park project. Between 1990 and 1997, EPA identified Potentially Responsible Parties (PRPs) at the site. In the late 1990s, PRPs engaged in negotiations with local water agencies and began initial design work on the project. After reaching a detailed agreement with seven local water agencies in March 2002, design work was completed and construction work began. Construction of the four planned groundwater extraction and treatment facilities was largely completed in 2006. Additional details are provided below.
EPA conducted the first "five-year review" of the project in 2007. A report summarizing the findings of the review is available on-line. Comprehensive annual performance evaluation reports for 2007 and 2008 are also available on-line (see Site Documents and Reports below).
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In 1989, the California Regional Water Quality Control Board, Los Angeles Region (RWQCB), working in accordance with an EPA-State Cooperative Agreement, began to identify the sources of the groundwater contamination in the Azusa/Baldwin Park area. The RWQCB inspected more than 1,400 commercial and industrial businesses in the area and required testing of soil and/or groundwater where contamination was observed or suspected. Using the test results, historical Federal, State and local records, responses to information requests, and other investigative techniques, EPA ultimately identified 21 parties as significant contributors to the groundwater contamination. The 21 companies have been named as PRPs. Hundreds of other companies have been sent "no further action" letters to inform them that EPA does not believe that they have contributed to the groundwater contamination.
From 1990 to 1993, EPA completed the Baldwin Park Operable Unit Remedial Investigation and Feasibility Study, which was an investigation of the nature and extent of contamination in the Azusa/Irwindale/Baldwin Park area and evaluation of cleanup options. The investigation included the compilation and analysis of sampling results from existing water supply wells, temporary reactivation and sampling of inactive water supply wells, installation of a 1,500-foot deep monitoring well, installation and sampling of more than two dozen shallow groundwater monitoring wells, development of a groundwater flow model of the aquifer, and preliminary discussions with local water agencies over their role in the cleanup. In 1993, EPA issued its proposed cleanup plan.
In March 1994, after review of hundreds of public comments, EPA selected a cleanup plan for the Baldwin Park area. The selected remedy, now constructed, includes four groundwater pump and treat systems capable of extracting and treating more than 26,000 gallons per minute, or 37 million gallons per day (MGD), of contaminated groundwater. The remedial objectives are to prevent future increases in, and begin to reduce, concentrations of groundwater contaminants in the Baldwin Park area by limiting further migration of contaminated groundwater into clean and less contaminated areas or depths that would benefit most from additional protection and by removing contamination from the aquifer. The Record of Decision (ROD) specifies extraction of contaminated groundwater at the downgradient end of two broad subareas of contamination, at locations and rates sufficient to hydraulically contain contaminated groundwater moving through each subarea during all anticipated groundwater flow conditions. The ROD was updated by the Explanation of Significant Differences in May 1999 (see link below).
In 1995, after EPA began to identify PRPs, many of the PRPs formed a group which began to collect data needed to design the facilities called for in EPA's cleanup plan. The group, known as the Baldwin Park Operable Unit Steering Committee, installed and sampled a network of eight 700 to 1,000 foot deep multilevel groundwater monitoring wells and further developed of a detailed groundwater flow model of the area. This work was completed in 1997.
At this time, negotiations also continued over the role of local water agencies in the cleanup.
Negotiations with the water agencies were initially focused on a proposal advocated by the Metropolitan Water District of Southern California to export the treated groundwater produced by the cleanup to Metropolitan's customers elsewhere in Southern California. Despite many studies and hearings and much lobbying on behalf of the Metropolitan Plan (termed the "Consensus Plan" by one of its supporters), the plan was not implemented.
Instead, in 1998, local support shifted to an alternative plan proposed by the Main San Gabriel Basin Watermaster (a court-appointed entity responsible for administering the water rights agreement in the San Gabriel Basin). The Watermaster Plan proposed that the treated groundwater be used locally, and that local agencies play a major role in designing, building, and operating the cleanup facilities. The Watermaster Plan resulted in part from the June 1997 discovery of another contaminant in the groundwater at potentially unsafe levels. The contaminant was perchlorate, an inorganic constituent of solid rocket fuel. Two other chemicals, N-nitrosodimethylamine (NDMA) and 1,4-dioxane, were also found in the groundwater in the Baldwin Park area after perchlorate was discovered. The originally planned treatment technologies (air stripping and/or granular activated carbon) are not capable of effectively removing perchlorate, NDMA, or 1,4-dioxane from water and, at the time, no proven perchlorate-removal technologies were available. The presence of perchlorate, NDMA, and 1,4-dioxane forced the closure of additional public water supply wells in the area, leading to renewed local interest in using the treated groundwater produced by the cleanup.
Also in 1997, EPA sent "Special Notice" letters to the 19 named PRPs to begin formal negotiations expected to result in a binding commitment by the PRPs, in the form of a Consent Decree, to design, construct, and operate the groundwater cleanup facilities. The negotiations were originally expected to conclude in late 1997, but were delayed following the discovery of perchlorate, NDMA, and 1,4-dioxane.
From 1997 to 1999, with EPA oversight, the Baldwin Park Operable Unit Steering Committee installed additional groundwater monitoring wells and carried out studies of perchlorate and NDMA removal technologies
In mid-1999, EPA resumed Consent Decree negotiations with the Potentially Responsible Parties and set a deadline for the PRPs to submit a "Good Faith Offer." In September, 11 of the 19 PRPs submitted an offer that met EPA's requirements for a "Good Faith Offer". The September 1999 offer was to design, build, and operate the cleanup facilities with or without the provision of public funds, to repay some (but not all) of the public funds already spent on the cleanup, and to begin the formal design process immediately rather than wait until negotiations were concluded.
EPA-PRP negotiations continued into early 2000, in an effort to translate the September 1999 offer into a binding commitment. EPA allowed negotiations to continue much longer than is typical because of strong local support for a negotiated settlement and because the PRPs kept their commitment to continue the design process during negotiations. The most difficult issues to resolve were the end-use of the treated groundwater, the role of the local Watermaster and water utilities in the cleanup, and repayment of EPA, State, and local funds spent on the cleanup. The California Department of Toxic Substances Control (DTSC) and the California Regional Water Quality Board (RWQCB) also participated in the negotiations.
Two other sets of negotiations occurred simultaneously. First, the PRPs negotiated among themselves to allocate liability for cleanup costs and responsibility for carrying out the cleanup work. Second, the PRPs and the Main San Gabriel Basin Watermaster continued their negotiations, with EPA as facilitator and with the help of an independent mediator, to resolve a number of issues, including the technology to be used for perchlorate removal, the number of treatment facilities to be constructed, local involvement in design, construction, and operation of the treatment facilities, and use of any public funds that may be available.
By June 2000, however, negotiations had not produced agreements between EPA and the PRPs, or between the PRPs and the Watermaster. EPA concluded that negotiations alone were unlikely to produce an agreement and, on June 30, 2000, issued a Unilateral Administrative Order ("the EPA Order") directing the 19 PRPs to complete the remedial design and make arrangements for the construction and operation of the groundwater extraction wells, treatment systems, and related cleanup facilities.
The PRPs complied with EPA's Order, but the design work required by the EPA Order was slowed by uncertainty over local involvement in the cleanup. Still unresolved in 2000 was the ultimate use of the treated groundwater, the selection of the perchlorate treatment technology, treatment facility locations, the extent to which existing water supply wells would be used as groundwater extraction locations, and the extent to which local water agencies would be involved in design and construction of the facilities. In January 2001 a 25-page preliminary agreement was reached between six water agencies and eight of the PRPs. Finally, in March 2002, after hundreds of hours of negotiations, active EPA mediation, assistance from professional third-party environmental mediators, multiple public hearings, and extensive media coverage, eight PRPs and seven water agencies signed a final comprehensive agreement. The 300-page Baldwin Park Project Agreement (available through a link below) commits the PRPs to fund the design, construction, and operation of the groundwater extraction, treatment, and conveyance facilities needed to satisfy EPA's cleanup goals and meet local water supply needs. The water agencies and their contractors have completed most of the design and construction work, with EPA and PRP oversight. The PRP-water agency agreement not only addresses funding and work responsibilities, but provides criteria for selection of water treatment technologies, establishes a cost consultant and risk manager, describes contracting requirements, requires payment of management and performance fees, requires efforts to obtain public funds, includes audit and insurance requirements, resolves certain lawsuits, and provides dispute resolution procedures.
The remedy is being built as four sub-projects, as described above under "Cleanup Approach". The first of the four sub-projects, the La Puente Valley County Water District project, was completed in 2000 and is now supplying the treated groundwater for potable use.
The second of the four sub-projects, the San Gabriel Valley Water Company B6 project, was substantially completed in 2004; and, in June 2005, began supplying potable water to residents and businesses in the area.
Construction of the third sub-project, the Valley County Water District sub-project, was completed in 2005; and, in November 2005, began supplying water to residents and businesses in the area.
Construction of the fourth and last sub-project, the San Gabriel Valley Water Company B5 sub-project, was substantially completed in 2006 and began supplying water to residents and businesses in the area in July 2008.
| Subproject | Status (as of May 2007) | Design and Construction Cost | Treatment Capacity (gallons per minute) |
| La Puente Valley County Water District | Operating since 2000 | $ 7 million | 2500 |
| SGVWC Plant B6 | Operating since 2005 | $30 million | 7800 |
| Valley County Water District | Operating since 2006 | $48 million | 7800 |
| SGVWC Plant B5 | Operation began 2007 | $21 million | 7800 |
| Project-wide costs |  | $9 million | |
| TOTAL: | | $115 million | 25,900 |
Remedial Action reports describing construction of each of the sub-projects are available by clicking on the links below under the heading "Site Documents and Reports, Technical Documents." Also available in the "Technical Documents" section are he 2007 and 2008 Annual Performance Evaluation Report, which includes a discussion of the status of the cleanup, performance monitoring activities in the previous year, and a series of tables and figures summarizing technical information about the cleanup and showing the extent of groundwater contamination.