SITE INFORMATION AND CORRESPONDENCE

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M"rMA Working To Restore Nature Task 2: Locate and destroy the remnant of ell MW 1, if possible. The well was severely'damaged during soil excavation activities in October 1993. As discussed with Mary Meays of P S/EHD the well will be considered sufficiently destroyed under any of the following conditions: the well remnant is located and the casing filled with n t cement grout from bottom to top using a tremie pipe; the well remnant is located but the casing is already packed with native clayey soil, effectively eliminat ng the potential for vertical migration; or the well remnant cannot be located or is inaccessible. Task 3: Backfill and compact the excavation it with the remediated stockpiled native soil. The-replaced,soil-will-be compacted to 90% prior to-restoring the site with 6-inch asphalt paving. Backfilling and compaction will be performed under a City of Stockton grading permit. Task 4: Drill and install a replacement well fo MW1 in the vicinity of the former well. The well will be installed to a total d pth of 25 feet below grade using 2-inch PVC casing and #2 prewashed silica sand filter pack. Slotted casing (0.010 inch slots) will be place from approximately 10 to 25 feet below grade. The well will be finished with a water tight well box. The newly installed well will be developed and a groundwater sample collected for analysis of BTEX, TPHg, and TPHd. Task 5: Resample the replacement well, along with existing wells MW2, MW3, and MW4, after a minimum of 30 days from the initial sampling of the replacement well. Task 6: Submit a closure report should groundwater contamination not be detected in any site wells. Work activities are expected to 'begin December 14$ 1994. -RESNA will 'notify PHS/EHD immediately when the status of the MW 1 well remnant is determined (expected the morning of December 15, 1994). 1500591L-121494.doc 2