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California RegCal Water Quality CAtrol Board <br />Central Valley Region4 1 <br />Karl E. Longley, ScD, P.E., Chair <br />Linda S. Adams. Arnold Schwarzenegger <br />.Secretarvjor Sacramento Main Office Governor <br />Environmental Internet Address: http:/hvww waterboards.ca.gov/centralvalicy <br />Protection 11020 Sun Center Drive #200 Rancho Cordova, CA 95670-6114 <br />Phone (916) 464-3291 Fax (916) 464-4797 <br />FD <br />28 February 2008 <br />Mr. Nathan Crum MAR -- v 2608 <br />Valley Pacific Petroleum Services, Inc. ENVIROWF.NT HEALTH <br />166 Frank West Circle PERMIT/SERVICFS <br />Stockton, CA 95206 <br />GROUNDWATER MONITORING WELL INSTALLATION REPORT, VALLEY PACIFIC <br />PETROLEUM SERVICES, INC., 930 VICTOR ROAD, LODI, SAN JOAQUIN COUNTY <br />Regional Water Quality Control Board - Central Valley Region (Regional Water Board) staff <br />reviewed the 4 February 2008 Groundwater Monitoring Well Installation Report (Report) <br />submitted by Ground Zero Analysis, Inc. (GZA) on behalf of Valley Pacific Petroleum Services, <br />Inc. (Valley Pacific) for the service station site (Site) at 930 Victor Road in Lodi. <br />The Report was submitted in response to our 28 November 2007 letter in which we requested <br />that by 25 January 2008, Valley Pacific submit a well installation report to define the extent of <br />soil contamination and groundwater pollution north and east of the source area and a <br />feasibility study (FS) report to evaluate alternatives to clean up the soil and groundwater at the <br />Site. The Report describes drilling and soil sampling activities associated with the 14 January <br />2008 installation of two monitoring wells, MW12 and MW13, and the 16 January development <br />and sampling of the wells. MW12 is north and upgradient of the Site, and MW13 is in the east - <br />central portion of the Site. <br />Lithologic logging of the borings shows that below 35 feet below ground surface (bgs), the <br />soils underlying the Site generally consist of alternating sequences of silt, clay, and sand <br />between 35 and 55 feet bgs and from 55 to 65 feet bgs where the boring was terminated. <br />Petroleum hydrocarbons were detected only in one soil sample obtained from the clayey sand <br />at 55 feet bgs in boring MW13. Laboratory analytical results show that the soil sample is <br />contaminated with 590 milligrams per kilogram (mg/kg) of total petroleum hydrocarbons as <br />gasoline (TPHg). Benzene, toluene, ethylbenzene, and xylenes (BTEX) were detected at 3.5, <br />2.0, 1.3 and 23 mg/kg. Volatile organic compounds (VOCs) typically associated with petroleum <br />hydrocarbons were also detected in the 55 -foot bgs soil sample at low concentrations. <br />Groundwater was first encountered at 60 feet bgs but rose to about 55 feet bgs. <br />Groundwater monitoring wells MW12 and MW13 are screened from 50 to 65 feet bgs and <br />were sampled on 16 January 2008 in accordance with the quarterly groundwater monitoring <br />program schedule. Groundwater monitoring at the Site is conducted pursuant to Monitoring <br />and Reporting Program (MRP) No. R5-2002-0827. Regional Water Board staff reviewed the <br />17 January 2008 Semi -Annual Groundwater Monitoring and Sampling Report, Third and <br />Fourth Quarters 2007 (Fourth QMR) and the 18 January Annual Groundwater Monitoring and <br />Sampling Report 2007 (Annual Report). During 2007 depth to groundwater varied from about <br />California Environmental Protection Agency <br />Za Recycled Paper <br />