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%ff <br /> r`=`_' Work Plan For Additional Groundwater Delineation and Ozone Microsparge System Installation,Tosco(Former BP)Station No.11195 <br /> September 19,2402 <br /> Task 5. Laboratory Analyses <br /> Selected soil and all groundwater samples will be submitted for chemical analyses to a <br /> California state-certified Hazardous Material Testing Laboratory. Soil and groundwater <br /> samples will be analyzed for Total Petroleum Hydrocarbons as gasoline (TPHg), <br /> Benzene, Toluene, Ethylbenzene, total Xylenes (BTEX) and Methyl tert-butyl ether <br /> (MtBE) by EPA Method 8260B. In addition, the groundwater samples will be analyzed <br /> for Ethanol, Tert-butyl alcohol (TBA), MtBE, Di-isopropyl ether (DIPS), Ethyl tert-butyl <br /> ether (ETBE), 1,2-Dichloroethane (1,2-DCA) Tert-amyl methyl ether (TAME) and <br /> Ethylene dibromide (EDB) by EPA method 8260B. The stockpiled soil sample will be <br /> analyzed for TPHg, BTEX and MtBE by EPA Method 801518021, as well as total lead by <br /> EPA Method 6010. <br /> OZONE MICROSPARGING SYSTEM INSTALLATION <br /> As an interim remedial measure GR proposes to install the K-V Associates, Inc. <br /> "C-Sparge" ozone microsparging system. Ozone microsparging is a process where <br /> ozone in air is introduced into the groundwater through specially designed spargers to <br /> create small "microbubbles." As these microbubbles rise within the groundwater, the <br /> dissolved volatile organic compounds are rapidly oxidized. Low total flow rates (2-6 <br /> s a cfm) are used. Any ozone not consumed in the direct reaction with hydrocarbons rapidly <br /> decomposes to oxygen. This has an added benefit of stimulating the natural biological <br /> degradation. <br /> Two areas are proposed to be treated (Figure 2). The first area is onsite in the vicinity of <br /> the former and current USTs (source area). Sparge points will be installed in the source <br /> area, at a depth of approximately 30 feet bgs. The second area will target the <br /> downgradient groundwater, and create a barrier along the southern site property <br /> boundary, which will treat groundwater flowing offsite. These sparge points will be <br /> installed along the site property line at a depth of approximately 30 to 35 feet bgs. All <br /> proposed sparge point depths are target depths. The actual sparge point depths will be <br /> determined during drilling based on the field conditions and stratigraphy encountered. <br /> Additionally, the proposed sparge point locations may change due to the presence of <br /> subsurface utilities. <br /> Task 1. Pre-Field Activities <br /> GR will obtain the necessary sparge point installation permits from the EHD. The proposed <br /> well locations will be marked and a private utility locator will be contracted to locate any <br /> underground utilities near the proposed drilling locations and Underground Service Alert <br /> (USA)will be notified a minimum of 48 hours prior to drilling. <br /> ..h <br /> 140193.14 4 <br />