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PSC INDUSTRIAL OUTSOURCING, LP 210 West Sand Bank Road, Columbia, IL 62236 (618)281-1543 Fax(618)281-7020 L Well Destruction Work Plan t • Facility Site Code: 19093 7 L' February 20, 2012 Page 3 of 4 VV L These wells include; W-1, MW -4, MW-!�MW-12, 12, MW- of concern vy}}i th, be destroy. ThM SP -1, SP-2,/SP-6, PZ -1, PZ -2, SP -A, and VW- 1!All drilling equipment will be decontaminated before and between drilling and destruction of each impacted well. A summary of analytical data for groundwater well samples is presented on Table 2. - The wells will be destroyed by over-drilling the well boreholes to total depth and removing all or as much as possible of the well casing. If retrieving the casing in -whole is not possible, over- drilling to total depth with a larger drill bit may be necessary to destroy the well casing. Upon completion of over drilling and casing removal, the SJCEHD grout inspector will be notified for inspection and grouting approval. Pressurized borehole grouting will be completed with a neat -cement grout mixture consisting of approximately 5 -gallons water to each 94 -pound bag of Type II -IV Portland cement. Pressure grouting will be completed by placing tremie rods into the borehole inside the hollow -stem L. augers. All pressure grouting will take place from total depth upwards. Once the boreholes have be by feed. I been grouted to 30 feet below ground surface (bgs), the borehole may grouted gravity no PSC will attempt to minimize groundwater being displaced on the surface during pressure W¢A� grouting by pumping water rising inside the auger. Groundwater displaced to the surface during I h r grout installation will be pumped out and/or captured and containerized in Department of ` Transportation (DOT) approved, 55 -gallon drums. Groundwater elevation data is presented on Table 3. Surface restoration will commence a minimum of 24 hours after completing the pressure borehole grouting of the well boreholes. The surface restoration will then be completed using hot -mix asphalt or concrete as appropriate. Any property or vegetation damage that inadvertently occurs as part of the necessary field activities will be properly restored. PSC intends to use Osborne �— Concrete Coring and Stanley Engineering to complete the surface restoration activities. In some unforeseen cases, wells may need to be pressure -grouted without casing removal due to unsafe proximity to subsurface utilities. These instances would be discussed upon occurrence in the field on a case-by-case basis with SJCEHD. According to San Joaquin County Well Standards, in some circumstances, wells may be pressure grouted with the casing left in-place. If the well is to be grouted in-place, the top 3 feet of the well casing shall be drilled out with an ` auger that is one -foot larger in diameter than the auger utilized to install the well. Additional 6 - inches of soil shall be removed from around the cutoff casing to expose it. The grout rods will be placed to total depth within the well casing. Pressure grouting will continue until grout spills out �- of the cut casing and fills in the excavated 6 -inch void beneath the top of cut casing and up to a minimum of 6 -inches above the cut casing. The soil, water, and well debris (IDW) generated during the well destruction activities, will be L. stored in DOT approved 55 -gallon drums. The drums will be transported to a licensed waste disposal facility for proper disposal. L. POST -FIELD ACTIVITIES The post -field activities include completion of the California DWR Well Destruction Reports and t.. the SJCEHD Well Destruction Completion Report. PSC will notify the property owner, PSC INDUSTRIAL OUTSOURCING, LP 210 West Sand Bank Road, Columbia, IL 62236 (618)281-1543 Fax(618)281-7020 L