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11-03-2001 Gea3Wv, LLC-Wel!Abandonment for Mwwan Page 2 of 2 Proposed,Field Procedures The abandonment of groundwater monitoring wells MWA, MW-2, and MW-3 will be performed by a C-57 licensed driller under the supervision of a State Certified Hydrogeologist (See Figure 1 for Well Locations). Prior to pressure grouting the wells, the depth to groundwater will be sounded to verify that the water levels are consistent with past readings and the total depth of each well's casing will be measured, in order to verify that no debris or obstructions are present in the well casing. If obstruction are present, they will be removed prior to pressure grouting and over drilling. Each well will then abandoned in-place, beginning at a depth of 98 feet bgs, by utilizing a tremie pipe with a sealing packer at its end to maintain pressure while pumping Portland Type 1111 cement mixed with approximately 5% bentonite grout (neat cement into the sand filter pack of the well). Pressure grouting will then be continued until a sufficient amount of cement has been pumped to ensure sealing of the sand filter pack and filling of the well casing so that the perched aquifer zone (i.e. between 80 and 82 feet bgs) and the top of the sand pack (i.e. @ 75 feet bgs) is sealed off from the deepest contaminated soil at a depth of 60 feet bgs (See Figure 2 for Cross Section). After the wells are pressure grouted from 98 feet bgs to 75 feet bgs, the grout will be allowed to set for a minimum of 72 hours. After the grout has set, each of the three wells will be over drilled with a hollow-stem auger through the bentonite seal (i.e. between 72 and 75 feet bgs)to 75 feet bgs, during which time, the old well casing and associated well construction materials will be removed. After each well has been cleaned out to 75 feet bgs, they will be grouted utilizing a tremie pipe with a sealing packer at its end to maintain pressure while pumping Portland Type 1/11 cement mixed with approximately 5% bentonite grout to within 3.5 feet of ground surface. The remaining 3 1/2feet will then be sealed with concrete and covered with AC pavement to match the surrounding pavement. Pressure grouting of the sand pack is recommended so that the process of over drilling will not cross contaminate the shallow gasoline contaminated soil zone with the deeper perched groundwater zone. The drill cuttings and decontamination water generated during abandonment activities will be stored on site in sealed Department-of-Transportation (DOT)-approved, 55-gallon metal drums to be transported to a legal point of disposal. After the wells have been properly abandoned, a well abandonment report, detailing the well abandonment process completed will be submitted to the County for review and approval. LIMITATIONS This report has been prepared in accordance with generally accepted environmental, geological and engineering practices. No warranty, either expressed or implied, is made as to the professional advice presented herein. The analyses, conclusions and recommendations contained in this report are based upon site conditions as they existed at the time of the investigation and they are subject to change. The conclusions presented in this report are professional opinions based solely upon visual observations made within individual soil excavations and of the site and vicinity as well as on interpretations of available information as designated in this report. GeoSoly, LLC, maintains that the limited scope of services performed in the execution of this investigation may not be sufficient to satisfy the needs, and/or requirements of all regulatory agencies or other users. Any use or reuse of this document, its findings, its conclusions and/or recommendations presented herein, is done so at the sole risk of the said user. 11-03-2001 GeoSoty, LLC-- Welt Abandonment for Nunan Page 2 of 2