ARCHIVED REPORTS_XR0010573 - Laserfiche WebLink

Home Browse Search

Tosco Corporation 4 Tosco Service Station 8671 8606 Thornton Road Stockton CA June 21 2002 to augment water supply when the other municipal wells cannot meet the demand This well is seldom used as a drinking water source, as another well identified as Colonial Heights Well #1 serves-as the primary back-up well to the City of Stockton water supply Well DW-3, however, continues to be sampled on a monthly basis to monitor groundwater quality According to documentation received from the SJCUD, Well DW-3 has a 14-inch diameter casing extending to approximately 110 feet bgs, and is approximately 225 feet deep Well DW-3 is also equipped with a 20-horsepower pump, which is capable of pumping at a rate of 312 gallons per minute Water supply well data are included in Table 4 Results of the door-to-door survey confirmed the existence of three water supply wells in the area One well was identified at Bear Creek Veterinarian Hospital (Well DW-2, Figure 4), located at 8728 Thornton Road Well DW-2 is located 444 feet north of the site The employees at the veterinarian hospital confirmed that the well is an active well, however, on-site personnel would not disclose the purpose of the water usage Another well is located at a residence (Well DW-4, Figure 4), located at 8732 Davis Road (180 feet north of the site) SECOR field staff located what appeared to be a domestic water supply well (Well DW-1, Figure 4) on the property located at 8855 Thornton Road and is 281 feet northwest of the site The resident was not available to confirm the existence of the well, and a well survey form was not completed by the property owner, however, the possible domestic well was housed in a similar enclosure as the previously identified wells in the field Water supply well data are included in Table 4 SECOR identified other sensitive receptors within 2,000 feet of the site (Table 4) The closest school is "A Better Road", located approximately 900 feet to the north of the site Two surface water bodies were also identified Mosher Slough (approximately 50 feet to 100 feet south of the site), and South Bear Creek (approximately 1,300 feet northwest of the site) Stockpiled Soil Approximately 8 tons of soil generated dunng drilling activities were stockpiled onsite One composite sample (4 sleeves to 1 sample) was collected from the stockpiled soil and analyzed for TPHg, BTEX, and MtBE by EPA Method 8015 Modified, and total lead by EPA Method 6010B Analytes were reported below laboratory detection limits, and the soil will be disposed of at Forward Landfill in Manteca, California Stockpiled soil analytical data is presented in Table 5 SUMMARY OF FINDINGS • Groundwater was encountered in sandy silt between 31 and 33 feet bgs, . • MtBE by EPA Method 8260 was reported in three of 19 soil samples (SB-1@28', SB-1,C@30', and SB-1@35') at concentrations of 0 89 mg/kg, 0 94 mg/kg, and 0 53 mg/kg, respectively, 077 43791 222/Assessment