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Mr. Robert Trommer U Comments on CUF Site Closure Recommendations for Various SitesPage 7 of 7 March 3, 2010 Claim No. 17042 - 15406 S. Tracf Blvd Trac This site has persistent moderate TPHg, and low ethylbenzene and xylenes contaminants in one well, MW-4. Wells toward the north, east and south"fare not impacted; there are no delineating wells toward the west. A domestic well is located approximately 135 feet southwest of MW-4. In November 2009 limited groundwater extraction (GWE) was implemented utilizing MW-4. Approximately 15,000 gallons were extracted from the well. Since then the well has been monitored monthly; concentrations were reduced, but may be rebounding. The consultant plans to complete the rebound testing with the March sampling event and then prepare a report of findings. The plume appears to be of limited extent, except toward the west, which is not characterized. Significantly impacted soil has not been encountered on the.site. There does not appear to be a significant contaminant mass present, but thek contaminants are persistent and there is a domestic well to protect. The EHD will issue a directive to prepare a site closure summary report, addressing plume delineation and evaluation;''of vapor intrusion and health risk issues, threat to the domestic well, and other site closure cbncerns. If a favorable report is received, the EHD anticipates site closure in nine to twelve months: Claim No. 17179 - 15 E. Grant Lire Road Trac Dissolved contaminant concentrations have declined to levels :.suitable for site closure consideration. The consultant has recently obtained grab grou6dwater samples to complete the lateral and vertical delineation of the site, and -the results a're pending. The EHD will direct completion of a vapor intrusion evaluation. Upon receipt of the results of the recent grab groundwater investigation and the vapor intrusion evaluation, the`EHD will initiate the site closure process if warranted by the additional information. The EHD anticipates site closure may be obtained in six to twelve months. Summary The EHD will be moving these sites to closure as rapidly as possible. The'EHD has responded previously to the CUF on these sites in response to the f►ie-year` reviews and the annual updates.tes. Direct comments mems from the CUF technical staff on the concerns expressed on the more problematic tic sites above are requested (specifically Claim Nos. 8431, 7709, 11775, 14118, 14349, 14353, 15211, 15890, and 17042). An EHD representative is available to meet with your technical staff if that would be helpful. '? If you need more information to complete your evaluation of these cases, please contact Nuel Henderson, Engineering Geologist, at (209) 468-3436, or nhendersonCa_sicehd.com. Sincerely, Nuel C. Henderson, Jr., PG Adrienne Ellsaesser, REHS#4 Engineering Geologist Acting program Coordinator Comments on CUF Site Closure Recommendations 0310.doc"