Fresno Municipal Sanitary Landfill

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 Actions

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.

Cleanup Ongoing

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.

Remedy Selected

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.

Cleanup Ongoing

Construction of a landfill cap, gas control wells and water treatment system commenced in May of 2000 and was completed in 2003.

Cleanup Ongoing

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.
In September 2005, the EPA completed the five-year review of the remedies for OU 1 and OU 2. Seven recommendations are being addressed as a result to ensure that the remedies remain protective in the future. See below for a copy of the complete five-year review report and the fact sheet summary.

Cleanup Ongoing

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.

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 is designed to address deeper groundwater contamination along the downgradient perimeter of the landfill. Installation of Phase II extraction and monitoring wells is currently underway.