SITE INFORMATION AND CORRESPONDENCE

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i STATE OF CALIFORNIA-Environmental Prot( Agency PETE WILSON, Governor CALIFORNIA REGIONAL WATEri QUALITY CONTROL BOARD CENTRAL VALLEY REGION` 3443 Routier Road, Suite A t,( _�f t �,.. , Sacramento, CA 95827-3098 " -, � :N� ��, PHONE: (916) 255-3000 FAX: (916) 255-3015 PM 2: 21 April 1994 Mr. Randy Smith Southern Pacific Transportation Company One Market Plaza San Francisco, CA 94105 SOUTHERN PACIFIC TRANSPORTATION COMPANY, OLD TRACY YARD, SAN JOAQUIN COUNTY We have reviewed your 16 March 1994 response to the comments we made on your December 1993 Work Plan for Further Site Characterization at the subject site. Your letter stated that Cleanup and Abatement Order (C&A) No. 92-707 was issued only in draft form. However, as you can see in the attached copy of the C&A with a cover letter, Southern Pacific Transportation Company (SPTCo) was indeed issued the C&A for the other rail yard. Please note the soil and ground water cleanup levels for lead. We still believe that further investigation is needed regarding the significantly high levels of barium (950 mg/kg), cadmium (14 mg/kg), copper (1,500 mg/kg), mercury (1.2 mg/kg) and zinc(1,900 mg/kg). You stated that because these concentrations are significantly lower than the California total threshold limit concentration (TTLC), that there is no concern. Materials that have concentrations above the TTLC are considered hazardous and must be disposed of accordingly. However, it is still possible, indeed likely in sone cases, that materials with concentrations significantly below the TTLC will still degrade water quality. To evaluate whether or not a particular constituent threatens water quality, you must consider the soluble concentration of that constituent as determined by the waste extraction test (WET). The WET was run only for copper. Therefore, WET analyses of these metals must be included as part of your work plan. In regards to our concern that SPTCo is postponing immediate soil cleanup activities to establish cleanup levels, you stated "SPTCo defends its technical approach to site remediation at a site with no ongoing activity potentially creating a source of release to the environment." High levels of lead and other metals in the soil are a potential source of release. It is irrelevant that ongoing activities are not occurring. SPTCo proposes to remediate the soil to 500 mg/kg of lead. We have sent the attached memo to the Department of Toxic Substances Control (DTSC) requesting input on this level. The proposed #ZP .