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Page 4 Brusca File No. 137-002 August 10,2017 Murphy Parkway Property Soil Gas Monitoring Workplan conditioned as necessary, and placed and compacted as engineered fill within various project areas. EXISTING SOIL GAS MONITORING WELL ABANDONMENT An existing soil gas monitoring well is situated within the northwesterly portion of the site (in the area of capped residual glass waste). As described above, past sampling of this well by AGE reportedly has not identified methane at levels considered to be a concern. It is proposed to abandon the existing soil gas monitoring well via over-drilling with a truck-mounted drill rig. Prior to the well abandonment work,the necessary permit will be obtained from the SJCEHD. The abandonment work will be performed by a licensed C-57 drilling contractor with oversight by the SJCEHD. Following over-drilling of the existing soil gas monitoring well, the resulting borehole will be sealed with neat cement grout in accord with SJCEHD requirements. A report documenting the soil gas monitoring well abandonment work will be prepared and submitted to the SJCEHD. PROPOSED SOIL GAS MONITORING WELL INSTALLATION General/Purpose As indicated above, past soil gas monitoring at the subject site has been limited to the sampling/testing of one soil gas well situated with the cap area on the northwesterly portion of the subject property. Discussions with the SJCEHD have indicated that the installation and monitoring of two new soil gas wells along the westerly property margin is required. The SJCEHD has relayed that this requirement is due to uncertainties regarding subsurface wastes that apparently exist directly westerly of the property beneath the adjacent cogeneration plant site at 17200 Murphy Parkway). As described earlier in this Workplan, remedial excavation up to the westerly property line on the subject site revealed wastes apparently extending beneath the cogeneration plant property; offsite wastes were not removed or characterized at that time. Two locations have been selected along the westerly margin of the subject property for installation of soil gas monitoring wells; these planned locations are shown on Plate 2. Soil gas monitoring well installation work will be performed in accord with standard environmental protocol and will be overseen by a Professional Geologist. Permitting,Notification,and Utility Clearance Prior to the planned soil gas monitoring well installation work, the necessary well permits will be obtained from the SJCEHD. Additionally, the SJCEHD will be notified of the well installation schedule at least one week prior to the work. The planned soil gas monitoring well locations will be marked and Underground Service Alert will be contacted to clear the locations of underground utilities.