WORK PLANS - Laserfiche WebLink

Home Browse Search

0 9 Beckman Road Page 20 of 24 Our Project Number: LES140024 September 12, 2014 Further Action Letter was issued by the Environmental He Ith Department on April 7, 1998 and by the California Regional Water Quality Control Board July 8, 1997. The second set of three USTs were installed in 1986 an 1987, and removed in 2001. These tanks were placed in a secondary container and monitored. Soil was tested when removed, and motor oil was detected at 9 feet bgs. A letter from the Health Department, dated March 19, 2002 confirmed the completion of the tank removals. is letter indicated that it does not relieve the owner of any liability under the California Healt i and Safety Code or Water Code for past, present, or future operations at the site, or respons bility to clean up any contamination associated with the site. Furthermore, the letter stated thi t any proposed site use may require further site characterization and mitigation. Additional soil sampling was conducted in 2003 by Kleinl elder. One of the four groundwater samples (MW-4, near the northern perimeter) containedPH-G, TBA, MTBE and TAME. MTBE was detected at 790 ug/l, which exceeds the State Primary and Secondary Maximum Contamination Limits for Drinking Water Standards of 1 and 5 ug/I, respectively. MW-4 is down-gradient from the former Shell Station (880 Victor, Road). It was determined that the current or past operations of the gas station have impacted groundwater at the subject property. Soil samples were collected in the wash down (stream Clean Area), Chemical Storage Area, retention basin ponds and the soil stockpile. None of the soil samples collected detected organophosphate pesticides or organochlorine pesticides. A Steam Clean Sump Removal/Over Excavation and Stockpile Removal Report completed by Kleinfelder dated July 2, 2004 was reviewed. Soil samples were taken in the area of the southern area of the former USTs (DB-2). At 30 feet bgs, TPH-D was detected at 82 mg/kg, TPH-G at 1,900 mg/kg, Toluene at 1,000 ug/kg, Ethyl benzene at 23,000 ug/kg and total Xylenes at 137,000 ug/kg. This is considered an REC. The�ame boring at 40 feet detected TPH- G at 1.4 mg/kg, Ethyl Benzene at 70 ug/kgm and total Xylenes at 320 ug/kg. At 50 feet no constituents were detected. Petroleum impacted soil remains in the eastern portion of the southern excavation at depths from approximately 25 to 45 feet, with the highest concentrations at approximately 30 feet. The former UST Stockpile and over excavated material from the steam clean sump area were hauled offsite 0 Forward Landfill. One of the six confirmation soil samples detected TPH-MO at concentrations of 26 mg/kg in the sump/steak clean area. These values of motor oil would not generally trigger additional sampling or enforcement actions by regulatory agencies for that area tested. However, as previously stated, the contaminated soil identified at 30 feet bgs that remains in-place does constitute an REC. 880 Victor, Shell StationA(, djacent North/Up-Gradient) Two 5,000-gallon leaded gasoline USTs and two 8,000 gallon unleaded gasoline USTs were removed from the property on December 2, 1994. These USTs were replaced with new USTs in 1994. Soil contamination was found at 21 and 25 feet bgs beneath the removed USTs. Seventeen monitoring wells were installed on-site, and three monitoring wells were installed off-site, one of which was located on the subject site (See Appendix A - Site Map). Petroleum Hydrocarbons and MTBE were detected in MW-7 and MW-14, located approximately 10 feet north of the southern border of this property/the northem border of the subject property. No detectable levels of gasoline constituents were detected in groundwater samples taken from 02014 Neil O.Anderson&Associates.Inc A Terfacon company