Laserfiche WebLink
Linda S. Adams 11020 Sun Center Drive #200, Rancho Cordova, California 95670-6114 REC ateQr <br />California Ropional Water Quality Con+")I Board <br />Central Valley Region <br />Katherine Hart, Chair <br />Secretary for Phone (916) 464-3291 • FAX (916) 464-4645 <br />Environmental http://www.waterboards.ca.gov/centralvalleY <br />Protection <br />7 December 2010 <br />Kerry Heckman, President <br />Connell Motor Truck Co., Inc. <br />2211 North Wilson Way <br />Stockton, CA 95208 <br />ENVIRONMENTAL HEALTH <br />PERMIT/SERVICES <br />DOCUMENT REVIEW, RIVER CITY PETROLEUM AND CONNELL MOTOR LIFT TRUCK, <br />2211 NORTH WILSON WAY, STOCKTON, SAN JOAQUIN COUNTY, <br />CASE NOS. 390991 AND SL1863936 <br />I reviewed the Semi Annual Report — March to September 2010 (Report) submitted <br />10 November 2010 by your consultant Advanced GeoEnvironmental Inc. The Report provides the <br />results of the 20 September 2010 groundwater sampling event, and monthly vapor sampling of the soil <br />vapor extraction/air sparging (SVE/AS) treatment system. Depth to water varied from 48' to 50' below <br />ground surface. Groundwater flow direction varied from south to north; groundwater gradients varied <br />from 0.003 ft/ft to 0.007 ft/ft over six hydrologic units. Maximum groundwater concentrations were total <br />petroleum hydrocarbons as gasoline (TPHg), 5,400 micrograms per Liter (ug/L); xylenes, 270 ug/L; <br />and 1,2-dichloroethane, 140 ug/L. The SVE/AS system operated 3,955 hours from April 2010 to <br />September 2010, and is currently operating. The SVE/AS vapor influent concentrations on <br />15 September 2010 were TPHg, 2,200 ug/L; toluene, 11 ug./L; ethylbenzene, 18 ug/L; and xylenes, <br />110 ug/L. The Report recommends continued limited monitoring and SVE/AS remediation. I also <br />reviewed the 18 October 2010 SVE vapor sample result in the State Water Resources Control Board's <br />GeoTracker website, submitted 2 November 2010 as Electronic Data Format (EDF), which shows a <br />significant decline from the previous month's SVE/AS vapor influent concentrations of xylenes, 2 ug/L. <br />Based on the significant reductions in SVE/AS influent concentrations, all remediation is to be <br />suspended immediately upon receipt of this letter. You will conduct one round of groundwater and <br />SVE influent vapor sampling per the approved schedule in January 2011. By 28 February 2011, you <br />are to provide the groundwater and SVE vapor data (data) to me electronically by email at the address <br />below. If the data do not show significant rebound in groundwater or SVE vapor, then a closure report <br />will be submitted by 30 March 2011, written in accordance with Appendix A — Reports, Tr-Regional <br />Board Staff Recommendations For Preliminary Investigations and Evaluation of Underground Tank <br />Sites, 16 April 2004, which may be downloaded electronically from our website at <br />http://www.waterboards.ca.govicentralvalley/water_issues/underground_storage_tanks/tri- <br />regionals_appendix_a.pdf. You may contact me regarding questions by phone at (916) 464-4615; or <br />by,e-mail at ibartonwaterboards.ca.qov. <br />/James L.L. Barton, P.G. <br />Engineering Geologist <br />cc: Robert L'Heureux, State Water Resources Control Board, Sacramento <br />Michael Infurna, San Joaquin County Environmental Health Department, Stockton <br />William Little, Advanced GeoEnvironmental Inc., 837 Shaw Rd., Stockton 95215 <br />California Environmental Protection Agency <br />DEC 08 Avler or <br />'Recycled Paper