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I� Christopher MQPalmer, PG, CEG, HG, Consulting ydrogeologist 1345 Kimberly Drive San Jose, CA 95118 ph. 4081267-5238; fax 4081267-7396 CMPRGCEGHG@aol.com Monitoring Well Destruction Approach There are four monitoring wells on the Boyd Service Center site at the locations ' shown on Figure 2, The exploratory boring logs and monitoring well construction details for each well are also attached. i Wright Environmental Services, Inc. last sampled the wells at the subject property in 2011 (see References). Groundwater samples collected in February 2011 indicated the presence of Total Petroleum Hydrocarbons as Diesel (TPHD) -present in Wells MW-1 (2,600 ug/l), MW-2 (52 ug/1) and MW-3 (260 ug/1). TPHD was not II detected in MW-4. Ethylbenzene was reported in MWA at a concentration of 0.54 ug/i. Benzene, MTBE, Methanol and Ethanol were not detected in any well. The EHD states two options for well destruction procedures: • Option 1. Wells that have laboratory data from the last sampling event that demonstrate presence of any contaminants of concern are to be destroyed by removing all the contents of the original borehole (well casing, screen, filter pack and grout sealant). The cleared borehole is i then to be sealed with neat cement by grouting from the bottom to top up to a depth of three feet below grade. All groundwater displaced to the surface during grout installation shall be pumped out of the excavation and j containerized for proper disposal. Any wells located. offsite require updated access agreements an/or encroachment permits to be submitted along with the EHD Well Destruction Permit Application. • 00 tion 2. Wells that have laboratory data from the last sampling event that report non-detectable concentrations of contaminants of concern, with acceptable laboratory detection limits, may be destroyed by pressure grouting with neat cement, applied from the bottom up via tremie pipe, while leaving the casing in place. Following that, a hole at least one foot larger that the originally drilled .borehole shall be excavated around the outside of the of the well casing to a depth of 3 feet below grade, and the well casing shall be cut off 6 inches above the bottom ofthis excavation and removed. The grout will used to seal the well shall then be topped off and allowed to spill over the into the excavation and fill it for a thickness of one foot to form a "mushroom cap" over the top of the cut casing. All groundwater displaced to the surface during grout installation shall be pumped out of the excavation and containerized for proper disposal. Any wells located offsite require updated access agreements an/or encroachment permits to be submitted along with the EHD. Well Destruction Permit Application. a i I Page 2 of 4