TWO CASE STUDIES OF COST-EFFECTIVE
REMEDIAL ACTIONS FOR PCB CONTAMINATED SOILS
Theodore G. Erler, III, Vice President
James Dragun, Soil Chemist
Donald R. Weiden, Civil Engineer
Kennedy/Jenks Engineers, Inc.
San Francisco, California 94105
INTRODUCTION
The environmental transport and transformations of the polychlorinated biphenyls (PCBs) are
determined by their physical, chemical, and biological properties. In addition, a number of site-specific geological and hydrological characteristics also affect their distribution and transport [1]. This
paper discusses two case studies in which cost-effective, environmentally acceptable remedial actions,
which considered PCB properties as well as site-specific characteristics, were developed for sites containing PCBs.
The State of California currently regulates the disposal and cleanup of PCBs on the bassis of proposed regulations (Draft Regulatory Criteria for Identification of Hazardous and Extremely Hazardous Wastes, October, 1982). In accordance with these proposed regulations, materials containing
PCB concentrations below 1.2 ppm are considered nonhazardous. Materials containing PCB concentrations between 1.2 and 12 ppm are considered potentially nonhazardous. Materials with PCB concentrations between 12 and 1200 ppm are considered a hazardous waste. Materials with PCB concentrations greater than 1200 ppm are considered an extremely hazardous waste.
CASE I
General History
The Case I project site was a land development site, which was the site of a heavy industrial complex in Northern California. One area of the site contained a fuel oil storage tank. Leaks apparently
developed in the tank's bottom and/or the tank's associated piping, allowing the release of oil to the
area below the tank. On one or more occasions during the tank's service life, oil stored in the tank and
released to the area through leaks was contaminated with PCBs (Aroclor 1260) from an unknown
source.
Demolition of the heavy industry complex, including the fuel oil storage tank, and site grading for
the redevelopment project began in the fall of 1981. During demolition, PCBs were identified in the
oil remaining in the tank and in oil trapped in rock fissures beneath the tank. After initial cleanup, site
grading proceeded until January, 1982 when a period of unusually heavy rainfall occurred. As a result
of heavy rainfall, the fuel oil tank site became saturated, and floating oil was observed in the former
oil tank construction area. This oil was sampled and analyzed, and the PCB concentrations in the oil
ranged from non-detectable to 48 parts per million.
Site Investigations
Several exploratory trenches were excavated to determine the depth and lateral extent of PCB contamination in the vicinity of the tank (see Figure 1). Heavy rainfall continued throughout January,
filling the exploratory trenches with rainwater. Oil continued to seep from the weathered rock form-
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