COMPLIANCE INFO - Laserfiche WebLink

Home Browse Search

JON Petroleum Tanker Spill Response,Sk,..—xcavation,and Confirmation Soil Sampling Result Re,.-.t Williams Tank Lines Fuel Tanker Spill,22934 E.Mariposa Road,Escalon,California Page 5 !_ ) Once the backfilling activities were complete, the excavation area was reformed to tirV`f i'' NMPNTAL existing shoulder of the east bound lane on Mariposa Road. San Joaquin Public WoW014LTH DEP'A;:F'i IENT Department met with Williams to confirm the shoulder area met with their expectations. CONCLUSIONS On September 19 and 20, 2013, Apex excavated and removed approximately 335 cubic yards of impacted soil. Stockpiled soil was later transported to Forward Landfill in Manteca, California. No soil remains stockpiled at the spill site. A total of twelve post excavation soil samples were collected for analysis. The soil samples consisted of eight soil samples from the side walls of the excavation and four base samples for the area excavated. Petroleum-impacted soil remains in place primarily towards the east end of the excavation pit at various depths, as indicated in Table 1. According to the San Francisco Regional Water Quality Control Board's (Region 2)May 2013 Environmental Screening Level (ESL) for TPHg in soil, all samples were reported below the ESL of 100 mg/kg except sample EXB-2. Although sample EXB-2 is reported above laboratory detection limits, it is presumed that impacted soil does not migrate any further vertically because sample B-4-15 is reported below laboratory detection limits at 15 feet bgs. The site surface and any previously existing structures, vegetation and miscellaneous objects have been restored to their original condition, in accordance with all of San Joaquin County's requirements. RECOMMENDATIONS Based on the excavation activities and the laboratory analysis of soil samples documented in this report Apex believes it would not be cost effective to further excavate the remaining amount of petroleum impacted soil. Apex does not feel that any additional site activities are warranted as a result of the documented release and cleanup activities. We hereby respectfully request that the CRWQCB provide regulatory closure for this spill and issue a letter stating no further action is necessary for the spill.