Laserfiche WebLink
California egional Water Quality Corvi Board � <br /> Central Valley Region <br /> Karl E.Longley,SCD,P.E.,Chair <br /> Linda S.Adams Arnold <br /> Secretaryfor Sacramento Main Office <br /> Environmental 11020 Sun Center Drive#200,Rancho Cordova,California 9567M114 Schwarzenegger <br /> Protection <br /> Phone(916)464-3291 •FAX(916)464-4645 Governor <br /> http://www.waterboards.ca.gov/centralvalley <br /> 23 April 2008 RECE V L�L�J <br /> Mr. Dale Gillespie APR 2 5 2008 <br /> Geweke Land Development and Marketing <br /> PO Box 1210 ENVIRONk1EN i HEALTH <br /> Lodi, CA 95241 PERMIT/SERVICES <br /> REPORT REVIEW, CLEANUP AND ABATEMENT ORDER (CAO) NO. 93-701, <br /> GEWEKE PROPERTY, 16 SOUTH CHEROKEE LANE, LODI, SAN JOAQUIN COUNTY <br /> I reviewed the Quarterly Report— First Quarter 2008 (Report), received 18 April 2008 and <br /> submitted on your behalf by Advanced GeoEnvironmental, Inc. (AGE). The Report provides a <br /> groundwater contour map, a Total Petroleum Hydrocarbons as gasoline (TPHg) <br /> isoconcentration map, and the analytical results from the groundwater monitoring event <br /> conducted on 21 February 2008 at your site (see enclosed Figures 2 through 4). Depth to <br /> water varied from 57 to 59 feet below ground surface. The downgradient groundwater <br /> direction was towards the south at a varying gradient of 0.001 ft/ft (onsite) to 0.003 ft/ft <br /> (offsite). Maximum groundwater concentrations were reported in offsite monitoring well MW-9 <br /> as TPHg, 4,000 micrograms per Liter (ug/L); ethylbenzene, 23 ug/L; xylenes, 28 ug/L, and <br /> 1, 2-dichloroethane, 7.8 ug/L. Onsite, only the MW-14 groundwater sample reported impacts, <br /> TPHg, 300 ug/L; toluene, 4.3 ug/L; and xylenes, 87 ug/L. The site is under active groundwater <br /> remediation by ozone injection. <br /> The Report states the ozone injection groundwater treatment (ozone) system was shut down <br /> for routine maintenance on 19 March 2008, and it could not be restarted due to a damaged <br /> ozone generator. The ozone generator is being repaired by the manufacturer, and the ozone <br /> system will be restarted by the end of April 2008. <br /> The Report recommends: <br /> • Continued groundwater monitoring under CAO No. 93-701, <br /> • Continued operations of the ozone system (after repairs), <br /> • Injection of ORCO (Oxygen Releasing Compound) to reduce residual petroleum <br /> hydrocarbons concentrations around MW-9, and <br /> • Destruction of the existing vapor (extraction) wells on-site (no rationale given for well <br /> destruction and no figure supplied for location for vapor wells) <br /> Comments: <br /> 1) 1 concur to the continuation of groundwater monitoring and the operation of the ozone <br /> system. <br /> 2) From October 2004 through December 2006, the ozone system operated onsite. From <br /> December 2006 through April 2007, AGE conducted a contaminant rebound test by <br /> California Environmental Protection Agency <br /> 0Z 1 Recycled Paper <br />