Laserfiche WebLink
6437 Banner Street • 2 3 November 2010 <br /> Lodi, San Joaquin County <br /> Comments: <br /> 1) You may reduce monitoring for MW-4B, MW-7A, MW-8B, EW-4 and EW-5 from semi-annual to <br /> annually. <br /> 2) The recommendations for reducing the frequency of sampling for bioassay (Acute Toxicity) in <br /> R5-2008-0085-013 is not approved as R5-2008-0085 specifically states quarterly sampling for Acute <br /> Toxicity is required without exception, and there is no provision for changing this requirement short of <br /> rescinding R5-2008-0085-013 and reapplying and receiving a site specific NPDES permit, which could <br /> take up to a year to complete at a higher cost to the project. <br /> 3) You may discontinue groundwater extraction in EW-10A. If MTBE is detected in EW-10A, then you <br /> will re-evaluate whether groundwater extraction is necessary from EW-10A in the monitoring report. <br /> 4)The recommendation for removing the MID-1 sampling of the treatment system is also not approved, <br /> since MTBE breakthrough of the carbon is typically first detected at MID-1 (after the first carbon unit), <br /> not at MID-2 (after the second carbon unit). You may allow the lab to hold all of the GWETS water <br /> samples and test each one individually from influent to effluent, stopping analyses when the last sample <br /> in line is non-detect for constituents of concern. Holding times must be met for all analyzed water <br /> samples. In effect, a non-detect intermediate sample becomes the effluent sample. <br /> 5) Based on emails from AGE, the annual R5-2008-0085-013 influent water sampling is scheduled for <br /> December 2010. The August 2010 results were from a new laboratory, and prior and subsequent <br /> analytical results indicate detections of TPHg, ethylbenzene, and xylenes may be the result of a <br /> laboratory analysis error. The results of the next annual sampling will be used to determine whether <br /> influent sampling for TPHg, ethylbenzene, and xylenes will revert back to monthly analysis for these <br /> constituents. <br /> If you have any questions, you can contact me at (916) 464-4615 or I can be reached bye-mail at <br /> Ibarton(a)waterboards.ca.gov. <br /> James L.L. Barton, P.G. <br /> Engineering Geologist <br /> cc: Mr. Michael infurna, San Joaquin County Environmental Health Department, Stockton <br /> Ms. Rupi Padda, 6437 Banner St., Lodi 95242 <br /> Mr. Timothy Cuellar, Advanced GeoEnvironmental Inc., 837 Shaw Rd., Stockton 95215 <br />