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ASSOCIATE! r(vvlr8 S INC 4.3 Remediation Activities In October 1999, ATC supervised the performance of a 24-hour groundwater pumping test Groundwater was pumped from well MW2 for a period of 24 hours Depth to water measurements were made in wells MW1, MW2, MW3, and MW4 during the groundwater pumping test Measurements were made in well MW5 manually with a depth to water probe Approximately 7,900 gallons of groundwater was extracted during the pump test and discharged to the City of Ripon municipal sewer system The results of the groundwater pumping test are summarized in ATC's Summary Report of Pumping Test and Remedial Investigation Feasibility Study, dated March 20, 2000 4.4 Soil and Pargewater Disposal Impacted soil cuttings generated during subsurface investigation activities were disposed of in March 2000 by ATC Associates at the Forward Inc Landfill in Stockton, California Purged groundwater generated during monitoring activities was regularly disposed of into the City of Ripon sewer system under permit with the City of Ripon Public Works Department Currently there are approximately 150 gallons of monitoring well purge water stored on site This purge water will be disposed of after the site has been granted NFA A summary of analytical results for soil is presented in Table 1, historical analytical results for groundwater are presented in Table 2, and historical groundwater monitoring data are presented in Table 3 5.0 EXISTING CONDITIONS 51 Soil Conditions 5.1.1 Site Geology ' Backfill material was encountered in soil boring SBI in the upper 10 feet of the soil column The soil in boring S133 consisted of a mixture of poorly graded sand and well graded sand from the surface to 11 to 14 feet bgs Soil from the remaining soil borings consisted of poorly graded ' sand from the surface to 11 to 14 feet bgs Soil from all borings consisted of well graded sand from depths between 1 I to 14 feet bgs and 21 feet bgs Soil from borings S137 through SB 11 consisted of poorly graded sand with silt from the surface to depths between 6 to 9 feet bgs and 1 I to 14 feet bgs Soil from depths between 6 to 9 feet bgs and 11 to 14 feet bgs to 31 feet, the maximum depth explored, consisted of poorly graded to well ' graded sand Soil in borings MW1, MW3, MW4, and MW5 consisted of poorly graded sand with silt from the surface to 6 5 to 10 feet bgs Soil from depths between 6 5 to 10 feet bgs and 31 to 35 feet bgs w 11309%reportsklosure doe 5