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Well Destruction Work Plan r�Or� Circle K Store No. 8671, 8606 Thornton Rd., Stockt July 24 California2020AW On December 12 through 14, 2001, one deep soil boring (SB-1)was drilled to an approximate depth of 63 feet below ground surface (bgs) and three additional groundwater monitoring wells documented i R. The reslts of work are MW-6 andreport-7) were instaed on-site by titled Site Assessment RepMW ortEdaatted June 21 u2002.tin November 2003, SECOR SEC6installed dp wells M -8 reported inPetroleum hydrocarbons soil and g oundwa enot r samples from the new wells. Vertical and lateral delineat onrof the plume has been completed. and SVE-2)were installed onsite by ls (SVE-1 SECOR?The r0esults of this work are documented5, to soil vapor extraction (SVE) eln SECOR's report titled SVE Well Installation and SVE Pilot Test Report, dated August 31, 2005. Based on the data collected during the SVE test, SVE technoloy was deterined not to be effective at removing he site becaugse of a small rad us of influence arates. hydrocarbons from the soil beneath and low mass removal rates In November 2008, Stantec installed eight oxygen injection wells (OS-1 through OS-8) as well as peroxide bench scale test. The OS wells were drilled to a depth of 49.5 feet conducted a hydrogen p bgs utilizing (PVC) blankrcasing Awith a 2 fooand were t longrsect on of 0.020--incheslot screen. The subsurface to the site is comprised of clays, silty sand and sandy silts to the total depth explored. Groundwater was first encountered at approximately 34.5 to 40.5 feet bgs during drilling activities. Soil and groundwater samples were submitted to Prima Environmental on November 12, 2008 for hydrogen peroxide bench-scale treatability testing. No other samples were collected during these activities. cygen injection 01 initiatedStantec oxygen l gen injection August 6,2010 and ceased injections on February 10, 201 . Stantec reinitiatedox ntatus Summary Report— Results are detailed snjection events Semiannualappeared to have been effective at lowering concentrations0 April 20, 2011. oxygenj of constituents of concern in groundwater at the site. in gs feet bgs to ate the lateral extent ovember o16, ATC advanced five CPT arbons downgradient of MW7n Petrole0um hyd ocarbonsuwere detected in of amounts in groundwater samples collected from CPT-4 at 107 to 110 feet bgs and from CPT-5 at 45 to 48 feet bgs. No other analytes including MTBE were detected n any of the groundwater samples collected at any depth at any location. Results were detailed in ATC's Assessment Report, dated December21, 2016. 3.0 PROPOSED SCOPE OF WORK The scope of work includes properly destroying monitoring wells MW-1, through MW-10; oxygen s shown on Figure 2. The w wells will be through d by overdrilling and soil for hells SVE-1 and SVE-2 to al depth of he original borehole. Well The wells will be destroyed by construction details are presented on Table 1. 2