Laserfiche WebLink
Ms. Mary Serra <br /> Page 2 of 6 <br /> August 10,2004 <br /> • Concentrations of BTEX in groundwater samples from upgradient well MW-1 are <br /> non-detect for the last three quarters and BTEX was detected in only one of seven <br /> post-remediation sampling events (see Tables 1 and 2), <br /> • Concentrations of petroleum hydrocarbons in groundwater samples have either been <br /> non-detect over the last four sampling events or are attenuating naturally with time <br /> (see Tables 1 and 2). The levels of TPH-d that have been detected in the last three <br /> sampling events are fluctuating at low concentrations. <br /> • Soil excavation has removed petroleum hydrocarbon impacted soil and side wall and <br /> bottom verification samples were non-detect or below action levels for TPH and <br /> BTEX,indicating soil removal activities have successfully removed the source of <br /> potential future impacts to groundwater. <br /> • A well survey conducted in October 2003 shows one domestic well within 2000 feet of <br /> the site,there are no irrigation municipal or industrial wells within 2000 feet of the <br /> site (Figure 4). <br /> The rationale for the NFA request along with supporting documentation,as outlined in the <br /> Tri-Regional Board Staff Recommendations for Preliminary Investigation and Evaluation of <br /> Underground Tank Sites—Appendix B: No Further Action Requests (CVRWQCB 1996),is <br /> discussed below. The Checklist of Required Data for No Further Action Requests at Underground <br /> Tank Sites is included as Attachment 2. <br />