SITE INFORMATION AND CORRESPONDENCE

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Former Chevron Station 9-8227 Page 2 of 3 Sutter Office Center July 08, 2014 242 Sutter Street Stockton; CA 95202 • Wells that have laboratory data from the last groundwater sampling event that show non-detectable concentrations of contaminants of concern and with acceptable laboratory detection limits, and are not in areas of known or suspected soil contamination, may be destroyed by pressure grouting from the bottom upward, while leaving the well casing in place. The top three feet or more of the well shall be drilled out with an auger that is at least one foot larger in diameter than the auger originally utilized to install the well, and the soil around the cut-off casing removed to the depth of an additional six inches below the new `top' of the cut-off casing. The grout sealant shall spill out of the top of the well casing to form a "mushroom cap" seal with at least twelve inches of neat cement grout poured six inches above and six inches below the top of the cut-off casing. • All groundwater displaced to the surface during grout installation shall be pumped out of the excavation to allow for EHD inspection and verification that the well has been properly destroyed. Contaminated groundwater pumped out of the excavation shall be containerized for proper disposal. • This site has two wells, located off-site on the City of Stockton right-of-way. Please submit a copy of a valid encroachment permit issued by the City of Stockton when submitting the EHD Well and Boring Permit Application for this well. • This site has one monitoring wells with conductor casing from 115 feet below surface grade (bsg) to ground surface in MW-1 D. The conductor casing may remain in place; however, the two-inch diameter Schedule 80 polyvinyl chloride (PVC) casing, filter pack, and grout, between the PVC casing and the conductor casing, must be removed and the borehole filled under pressure from total depth to surface with 10.3 Sack sand/cement grout, forming a "mushroom cap" at approximately three feet bsg as described in bullet #3 above. After the EHD has approved the well destruction work plan, you may submit an EHD Well and Boring Permit Application form along with the access agreement, Master File Record form, Licensed Contractor's Declaration form and appropriate fees. The permit fee for the destruction of each well is $125, along with a $375 Inspection Activity fee per parcel. A review of the site records indicate that eight monitoring wells currently are installed. A fee of $1,750 (8 x $125 + 2 x $375) will be required for the well destruction permits. (Please note that in August 2014 the EHD fee-rate may increase.) The wells must be destroyed within ninety days of the date of this letter, and the well destruction report containing the manifests from the waste disposal must be submitted to this agency within sixty days of completing the well destructions.