ARCHIVED REPORTS XR0006250 - Laserfiche WebLink

Home Browse Search

Project No 014-95262 Page No 6 former UST's According to file review and interviews the Safeway employees, the diesel product lines were not removed nor did any sampling along the lines occur when the UST's were removed in 1987 ' An attempt was made to locate the product lines under the 8-inch thick concrete driveway which r, occupies the majority of the area between the former UST's and the boiler room This area was surveyed using a Schonstedt Instrument Co model MAC-51B magnetic and cable locator The results of the attempt to identify the diesel lines were inconclusive due to interference from other nearby natural gas and water underground pipelines Therefore, the accuracy of the diesel product lines location on a site utility map provided by Safeway was checked to determine if the map could be used to determine line sampling locations Scaling distances from other objects present both on the map and on the ground suggested the map was accurate The projection of the product lines, based on interpretation of the map, intersected the cut-off riser portions of the original supply and return lines still present just outside the boiler room wall Based on the favorable results above, three locations along the trace of the product Imes were sampled (samples KHA-1, KHA-2, and KHA-3) The samples were collected at depths of 3 to 3 5 feet bgs These sampling depths were based upon a common product line burial depth of approximately two feet bgs because the actual burial depth of the diesel supply and return lines is unknown Results were not detected for TPH-D, TPH-G, BTEX Sample location KHA-4 was chosen based upon the existence of a former acid neutralization tank at this location The tank held limestone chips and was placed along the wastewater line which serviced the south-central portion of the main building The purpose of the tank was to help mitigate periodic acidic discharges from the Safeway analytical laboratory which were generated during equipment cleaning These discharges were attributed by Safeway as the cause of violations of their City of Stockton wastewater discharge permit This location would also detect a significant release from the nearby diesel product lines due to the low permeability nature of the near surface soils The sample contained 1 0 mg/kg TPH-D and had a pH of 7 3 No TPH-G or BTEX were detected Sample location KHA-5 was placed to investigate a three-compartment clarifier along another wastewater line originating from the south portion of the building This location was also close enough to the diesel product Imes to detect a significant release Low concentrations of TPH-D and TPH-G were detected at 3 6 and 2 6 mg/kg, respectively No BTEX was detected and no nitrate was detected An attempt to collect a sample deeper than three feet bgs at the KHA-5 location was met by auger refusal at 4 feet bgs A slight oily odor, similar to that noted in the 3 feet deep sample, was noted at this depth No sample was obtainable KRAZAN& ASSOCIATES, INC Offices Serving he Western United States 95262 rsz