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