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Emergency Remediation 2480 Tracy Blvd., Tracy, CA. • Page 19 contaminated soil excavated from the subsurface and it contained less than 50 cubic yards of material. It was released to the general construction contractor after it had undergone somewhat less aeration than was the case for the other four spreads because, at the time it was being treated, there was an urgent need to release soil to be used as fill under the floor slab of the car-wash and lubrication-service facility so as to avoid costly delay to the construction work. Although the treated soil from Soil Spread No. 2 contained trace concentration of some components of fuel hydrocarbons, those traces were at least an order of magnitude less than the strategic objectives set by either the emergency remediation plan or the specific guidance provided by SJCPHS regarding the required degree of treatment of the contaminated soil. The rare traces of analytes of concern that were detectable in a small number of samples from the other four soil spreads were so insignificant that, for all practical purposes, the soil aerated in those spreads was, on completion of the treatment, considered to be clean. All of the treated soil has been placed and compacted as engineered fill needed to raise the grade of the site to accommodate the revised basement-slab elevation. The total volume either has or will be covered by floor slabs or the concrete paving that will extend over essentially the entire area of the site. IRETURN OF CONTROL OF SITE TO GENERAL CONTRACTOR The San Joaquin Company's engineer in responsible charge of the remediation work released the final spread of treated soil for use by the general construction contractor on May 2, 1996. At 15:30 hours on the same day, less than 30 days from the date contamination was first identified in the subsurface, full control of the site was returned to the general contractor, and that event was reported to the SJCPHS. RECOMMENDATIONS Emergency remediation of soil and groundwater at 2480 Tracy Boulevard was successfully completed with minimum delay to construction of the new car-wash and lubrication-service facility that will be operated on the property. We understand that none of the construction work yet to be completed will require excavation to depths sufficient to penetrate into the zone of contaminated soil. However, care should be exercised during the remainder of the work to check for any unexpected, visual or olfactory indicators of gasoline. When construction is complete, substantially all of the site will be under concrete paving so that there should be no concern about either the treated soil that has been used as engineered fill or the gasoline-affected soil at depth below the surface, unless fixture deep excavations were to be made on the property at some future date. r