Laserfiche WebLink
San Joaquin County <br /> pPp U,IN C Environmental Health Department DIRECTOR <br /> Donna Heran,REHS <br /> 1868 East Hazelton Avenue <br /> PROGRAM COORDINATORS <br /> � < Stockton, California 95205-6232 Robert McClellon,REHS <br /> Jeff Carruesco,REHS,RDI <br /> Kase <br /> Foley, <br /> EHS <br /> • 0'.., �. �P • Website:www.s Ov.or 1ehd Linda urkat ,RE <br /> 9C�FORC� 19 9 Linda Turkatte,REHS <br /> Phone: (209)468-3420 Rodney Estrada,REHS <br /> Fax: (209)464-0138 Adrienne Ellsaesser,REHS <br /> September 26, 2013 <br /> SIERRA LUMBER MANUFACTURES <br /> P O BOX 6216 <br /> STOCKTON, CA 95207 <br /> Subject: 375 W. Hazelton Ave. (Case 2) Lop Site Code: 1644 <br /> Stockton, CA 95203 <br /> The San Joaquin County Environmental Health Department (EHD) has reviewed Groundwater <br /> Monitoring Report-Second Quarter "2013" (Quarterly Report) and Dual Phase Extraction <br /> Remediation Report-Second Quarter 2013 Sierra Lumber Manufactures, Inc. (Case No. 2) <br /> (Remediation Report) prepared by your consultant Advanced GeoEnvironmental, Inc. (AGE) on <br /> your behalf for the subject site. The EHD has the following comments regarding the two <br /> reports. <br /> Dual phase extraction (DPE) remediation began on-site in August 2012 to cleanup soil and <br /> groundwater impacted by the on-site unauthorized release. The Quarterly Report indicates <br /> groundwater contamination in all wells continues to decline during active remediation, but <br /> groundwater contaminant concentrations in MW-15, located in the source area, remain elevated <br /> and are not declining as rapidly as expected after one year of active DPE remediation. <br /> In the Remediation Report, AGE has recommended connecting MW-15 to the DPE remediation <br /> network. MW-15 is located three linear feet northeast and up-gradient of existing DPE-1, is <br /> constructed with 2-inch diameter well casing instead of the 4-inch diameter casing used for <br /> DPE-1, has similar well construction, and has the same total depth as DPE-1. During the DPE <br /> pilot test in 2010, AGE estimated the radius of influence (vacuum) from DPE-1 to be 39 feet <br /> laterally. If the radius of influence is 39 feet, it seems that DPE-1 should be capable of <br /> capturing contamination three feet away. AGE's recommendation in the Remediation Report to <br /> include MW-15 to the already existing designed and installed DPE system does not appear to <br /> be warranted at this time. If MW-15 is not sealed properly at the surface, a short circuiting of <br /> leaking air may be reducing the effectiveness of DPE-1. Please ensure that MW-15 is sealed <br /> and not leaking air through the top of the well casing or grout seal during applied vacuum at <br /> DPE-1. <br />