20    EVALUATION OF DISCHARGES FROM A HAZARDOUS
WASTE FACILITY TO A POTW
Joseph M. Wong, Project Manager
Brown and Caldwell Consultants
Walnut Creek, California 94596
Antoinette M. Bertolero, Deputy Director of Public Works Department
City of Benicia, California 94510
INTRODUCTION
Since 1980, hazardous waste disposal has become an increasingly critical problem in the United
States. More and more publicly owned treatment works (POTWs) are being asked to help solve
industrial and hazardous waste disposal problems. These problems may range from disposal of
contaminated groundwater from a leaking gas station storage tank to acceptance of effluent from a
centralized waste treatment facility1.
One of the better known examples is the discharge of treated groundwater from the Stringfellow
hazardous waste disposal facility, a Superfund site, to two wastewater treatment plants operated by
the County Sanitation Districts of Orange County in southern California. From December 1985
through the end of 1988, nearly 26 million gallons of water from the Stringfellow site was treated and
discharged to these POTWs2.
A POTW may accept wastes from these facilities for many good reasons. For example, disposal to a
POTW may be the best technical solution to an environmental problem, because a POTW generally
can provide a large dilution ratio for the waste. A POTW also has the resources to tackle treatment
reliability problems. In some cases, the POTW board and management may feel a public responsibility to help to solve hazardous waste treatment problems. They are willing to accept the risk to fulfill a
public obligation. In other cases, a POTW may accept these wastes for a fee that will defray some of
the rising costs of operation and maintenance (O&M).
Before accepting these wastes, however, a POTW should conduct a careful evaluation of the impact
the discharge may have on the facilities both technically and legally. This paper presents a summary of
such an evaluation. The proposed discharge was to a POTW in California. It consisted of treated
groundwater, landfill leachate and impounded wastewater from a hazardous waste disposal facility.
This evaluation focused primarily on the technical aspects.
BACKGROUND
International Technology (IT) Corporation's Panoche facility, located approximately two miles
northeast of the City of Benicia in an unincorporated area of Solano County, California, is a Class 1
hazardous waste disposal facility with a land area of approximately 240 acres. The facility began
operation in 1968 to receive, treat, and dispose of hazardous industrial solid and liquid wastes in
evaporation ponds and landfills. IT purchased the facility in 1975 and continued to receive hazardous
wastes for disposal until December 1986. IT voluntarily stopped receiving solids at the facility in July
1986 and ceased receiving all wastes in December 1986 to comply with an order from the California
Department of Health Services (CDHS) related to drum burial areas at the facility.
Using the authority established by the California Toxic Pits Cleanup Act (TPCA), the San Francisco Bay Regional Water Quality Control Board (RWQCB) required IT to close its evaporation
ponds. These ponds contained several million gallons of water contaminated with various pollutants.
IT used the ponds to evaporate landfill leachate and groundwater recovered from the site. Pond
closure will involve dewatering the ponds and finding other means to dispose of the leachate and
groundwater that will continue to be generated.
45th Purdue Industrial Waste Conference Proceedings, © 1991 Lewis Publishers, Inc., Chelsea, Michigan 48118.
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