Pacific Southwest, Region 9: Superfund
Serving Arizona, California, Hawaii, Nevada, the Pacific Islands, and Tribal Nations
Fresno Municipal Sanitary Landfill
EPA #: CAD980636914
Congressional District: 20
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Description and History
NPL Listing History
NPL Status: Final
Proposed Date: 06/24/88
Final Date: 10/04/89
The 145-acre Fresno Municipal Sanitary Landfill site was owned and operated by the City of Fresno (City) from 1935 until it was closed in 1989. While conducting tests in 1983, the California Department of Health Services found that methane gas and vinyl chloride had migrated from the landfill to the surrounding areas. These tests also concluded that contaminated groundwater had migrated off-site to several private residential wells located nearby. The City installed monitoring wells around the landfill perimeter in 1984. Subsequent tests indicated that volatile organic compounds (VOCs) were present in groundwater samples collected from wells at the edge of the landfill. Nine municipal wells are located within three miles of the site. Water from these wells empty into a blended system that serves the City of Fresno. The general distribution area of the system serves approximately 300,000 people. Several irrigation and private residential wells are located within a few thousand feet of the site.
Contaminants and Risks
- Soil and Sludges
Ambient air samples collected at the landfill contained high concentrations of methane and vinyl chloride, and lower concentrations of VOCs. As stated above, groundwater is contaminated with VOCs. Since private wells located south of the landfill are contaminated with VOCs, area residents who depend on these wells as their sole source of drinking water could be exposed to site-related contaminants. The City has installed filters on the affected wells
Investigation and Cleanup Activities
The implementation of remediation at the Fresno Sanitary Landfill is addressed by the creation of two Operable Units. Operable Unit 1 includes remediation of the landfill through the construction of an engineered cover and a landfill gas collection system. Operable Unit 2 has been established to remediate contaminated groundwater.
On June 10, 1998, EPA and the City entered a formal agreement called a Consent Decree (CD) with the District Court. This agreement formalizes the final cleanup actions for the site. The CD calls for the City to begin the construction of Operable Unit 1 and develop the remedial design, construct and conduct the cleanup effort for Operable Unit 2.
Initial Interim Actions: In 1984, the City installed wells around the perimeter of the landfill to monitor methane and groundwater. The City also constructed landfill gas migration barriers on east and west sides of the landfill to prevent methane from migrating off-site to nearby homes. In 1990, the City began the removal of migrating landfill gas containing VOCs. The treatment involved placement of an active vacuum on an existing gas migration barrier to enhance its effectiveness. The landfill gas vacuum action was completed in 1991.
Groundwater: As stated above, in 1990, the City began an investigation into the nature and extent of groundwater contamination. As a result of the findings of that investigation, EPA selected a cleanup remedy in September of 1996.
Trash and Landfill Gas Contamination Investigation: The City began an investigation into the nature and extent of contamination at the Fresno Sanitary Landfill in 1990. The study addressed contamination in the groundwater, landfill gas, soils, leachate, and surface gas emissions. As a result of the findings of that investigation, EPA selected a cleanup remedy for Operable Unit 1 in 1993 that called for capping the landfill, constructing a gas collection system, and building a stormwater management system.
Construction of a landfill cap, gas control wells and water treatment system commenced in May of 2000 and was completed in 2003.
Start up of the landfill flare and the water treatment system began the week of September 10, 2001 as Phase 1 of the Remedial Action. Phase 1 of the Remedial Action is designed to capture and treat groundwater contaminants along the downgradient leading edge of the landfill. Prior to Phase 1, the City of Fresno initiated an Early Groundwater Remedial Action in May 1999 which consisted of the operation of three groundwater extraction wells and two, portable treatment units in an effort to expedite groundwater cleanup. As stated above, full operation of the groundwater treatment system started September 2001. Initiation of Phase 1 remedial activities includes the operation of five groundwater extraction wells located along the downgradient perimeter of the landfill. The extracted groundwater is treated through a packed tower aerator which is used to volatilize and remove contaminants from groundwater. Contaminant off-gas is incinerated by the landfill gas flare.
EPA is continuing to work with the City of Fresno and the State to develop institutional controls to protect the remedies for OU1 and OU2. The Explanation of Significant Differences (ESD) completed in September 2012, specified that the Landfill Restrictive Covenant and Sports Complex Restrictive Covenant were finalized, executed, and recorded so that the remedy can be protective in the long-term as noted in the Second Five-Year Review Report mentioned above.
Groundwater: In 2007, evaluation of the Phase I of the Remedial Action was completed and Phase II of the Remedial Action was initiated. Phase II was designed to address deeper groundwater contamination along the downgradient perimeter of the landfill. The groundwater treatment plant began operation in 2001 with five extraction wells in the shallowest (A) aquifer. Phase 2 construction activities occurred between 2007 and 2008 with the addition of two extraction wells in the deeper B-aquifer. One additional lower B-aquifer extraction well was installed as part of Phase 2 Enhancements that occurred between 2011 and 2014. In December 2015, the evaluation of the Phase 2 Enhancements concluded that two C-aquifer extraction wells were needed to achieve hydraulic containment. Design of the extraction wells, monitoring wells, and system integration was completed in February 2017. Construction is planned to start in September 2017.
Cleanup Results to Date
The Third Five-Year Review Report, completed on August 31, 2015, concluded that:
Land use has not changed since the last FYR. Exposure pathways from soil and groundwater are being controlled through ICs. A Well Assessment and Prohibition Program prohibits and/or restricts well installation on or near the Site. Two restrictive covenants (one for the landfill and one for the adjacent Sports Complex) recorded in 2012 provide further restrictions on groundwater use and provide protections for the remedy.
The remedy for OU1 is protective of human health and the environment. The landfill cap prevents exposure to contaminated soil and materials within the landfill. The landfill gas extraction and treatment system controls the landfill gas exposure.
The remedy for OU2 currently protects human health and the environment because exposure pathways for groundwater are being controlled. Exposure pathways to contaminated groundwater that could result in unacceptable risks are prevented through restrictive covenants and a wellhead protection program; furthermore, wellhead filtration systems and bottled water substitutes are provided to some homes immediately adjacent to the Site. However, in order for the remedy to be protective in the long-term, effective capture of groundwater contamination in all aquifers beneath the Site must be achieved to prevent further plume migration and to ensure protectiveness.
Potentially Responsible Parties
Potentially responsible parties (PRPs) refers to companies that are potentially responsible for generating, transporting, or disposing of the hazardous waste found at the site.
Documents and Reports
|06/01/98||EPA Enters Agreement with Fresno|
|06/01/99||EPA and City of Fresno Start Construction of the Landfill Cap and Early Groundwater Cleanup Action|
|06/01/00||Notice of Construction Start of Fresno Landfill System|
|08/01/01||Groundwater Treatment System Construction Underway|
|03/01/05||U.S. EPA begins Five-Year Review of Cleanup at Site|
|12/01/05||EPA Completes Five-Year Review of Cleanup at Site.|
|09/30/93||Record of Decision|
|09/30/96||Record of Decision|
|09/27/12||Explanation of Significant Differences|
|09/01/05||First Five-Year Review Report|
|09/30/10||Second Five-Year Review Report|
|08/31/15||Third Five-Year Review Report|
Public Information Repositories
The public information repositories for the site are at the following locations:
Fresno County Central Library
2420 Mariposa Street,
Fresno, CA 93721
EPA Site Manager
Mail Code SFD
75 Hawthorne Street
San Francisco, CA 94105
EPA Community Involvement Coordinator
Mail Code SFD
75 Hawthorne Street
San Francisco, CA 94105
EPA Public Information Center
8800 Cal Center Drive
After Hours (Emergency Response)