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Geosynte& <br /> consultants <br /> 3.2 Utility Clearance <br /> Monitoring well locations will be marked with white paint, and USA-North will be contacted a <br /> minimum of 48 hours prior to commencing intrusive subsurface activities. Additionally, a private <br /> utility locator will be contracted to perform a geophysical survey of the area near each well location <br /> to identify and mark utilities, pipelines, or other subsurface obstructions that may be present. <br /> 3.3 Monitoring Well Destruction Activities <br /> Prior to well destruction, the total depth of each well will be measured by Geosyntec field staff <br /> with a water level sounder to confirm there are no obstructions in the well casing. A licensed C-57 <br /> driller, under the direct supervision of Geosyntec personnel, will perform the well destructions. <br /> The groundwater monitoring wells will be destroyed by pressure grouting, unless otherwise <br /> directed by SJCEHD during the permitting process.I <br /> A slurry of neat Portland cement will be pumped through a tremie pipe from the total depths of the <br /> well to approximately 2 feet bgs. Following emplacement of the grout, a pressure of 25 pounds <br /> per square inch will be applied and maintained for 5 minutes to force the sealing material through <br /> the existing perforations of the well casing into the surrounding formation. Any above-grade well <br /> monument and well box will be removed. <br /> A hole at least 1 foot larger in diameter than the original borehole will be excavated around the <br /> outside of the well casing to a depth of at least 3 feet below the ground surface, and the well casing <br /> will then be cut off 6 inches above the bottom of this excavation and removed. The grout used to <br /> fill the well will be allowed to spill over into the excavation and fill it for a thickness of 1 foot and <br /> form a "mushroom cap" which has a diameter of at least 1 foot greater than the diameter of the <br /> original borehole. The remainder of the excavation will be backfilled with native material until <br /> flush with the surrounding grade. The removed well casing section will be disposed of as <br /> construction debris. <br /> ' Similar to MW-6,which was destroyed in 2025,MW-5 can only be destroyed by pressure grouting due to its location <br /> within the UPRR/CNSF right-of-way and proximity to a Kinder Morgan natural gas pipeline,since no drilling or other <br /> mechanical methods are allowed within 10 feet of a gas line. <br /> Well Destruction Work Plan 5 May 2026 <br />