Laserfiche WebLink
California F rjional Water Quality Cor+rol Board 4—' i <br /> Central Valley RegionQW; `Katherine Hart, Chair <br /> Linda S.Adams 11020 Sun Center Drive#200, Rancho Cordova,California 95670-6114 Arnold <br /> Secreiarl for Schwarzenegg <br /> Phone(916)464-3291 •FAX (916)464-4645 <br /> bivironnienlal http://www.waterboards.ca.gov/centralvalley Governor <br /> Prolecllo77 <br /> 20 September 2010 SEP 2 2 Zu10 <br /> ENVIRuIv vin 1 HEALTH <br /> Mr. ,lames Diel PERMIT/SERVICES <br /> Manager, Site Remediation <br /> Union Pacific Railroad Company <br /> 9451 Atkinson Street, Suite 100 <br /> Roseville CA 95747-5528 <br /> BIOTREATMENT BEDS POST-REMEDIATION INVESTIGATION REPORT, UNION <br /> PACIFIC RAILROAD COMPANY FORMER TRACY MAINTENANCE FACILITY, <br /> 720 EAST 6TH STREET, TRACY, SAN JOAQUIN COUNTY <br /> The California Regional Water Quality Control Board, Central Valley Region (Central <br /> Valley Water Board) staff has received and reviewed the Biotreatment Beds Post- <br /> Remediation Investigation Report (Report), dated 24 August 2010, prepared by <br /> ARCADIS U.S., Inc. (ARCADIS) on behalf of Union Pacific Railroad Company (UP). <br /> The Report provides the results of soil and groundwater sampling in the former <br /> Biotreatment Beds 1 and 2, which occupy approximately 4.7 acres of the former Tracy <br /> Maintenance Facility. Central Valley Water Board staff requested these data to <br /> evaluate the effectiveness of the biotreatment remedy as described in Cleanup and <br /> Abatement Order (CAO) No. 92-707. Biotreatment Beds 1 and 2 contain soil that was <br /> excavated from the former surface impoundment known as the Toxic Pits Cleanup Act <br /> (TPCA) pond. <br /> Per the requirements of CAO No. 92-707, soil remaining on site must contain less than <br /> 50 milligrams per kilogram (mg/Kg) Total Petroleum Hydrocarbons quantified as diesel <br /> (TPHd), and groundwater outside the downgradient limit of the former pond must <br /> contain less than 100 milligrams per liter (mg/L) TPHd in order to complete the cleanup <br /> of the TPCA pond and rescind the CAO. <br /> In the Report, ARCADIS provides responses to Central Valley Water Board staff's <br /> requests regarding sampling and analysis in the biotreatment beds in a letter dated <br /> 19 February 2009. We specifically requested that UP perform soil gas sampling, and <br /> sampling of soils (for metals by the Waste Extraction Test using deionized water) and <br /> groundwater (for polynuclear aromatic hydrocarbons [PAHs] and metals), or provide a <br /> justification for omitting these analyses, in order to satisfy the requirements of the CAO. <br /> ARCADIS provided data from previous investigations to argue that these additional <br /> sampling and analysis activities were not necessary. <br /> California Environmental Protection Agencr- <br /> Irl <br /> %C7Recycled Paper <br />