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As I mentioned below, this request is time-critical, as we are currently in the field investigating and will be <br /> installing wells. We would highly appreciate your consideration and consent to our request so that we can <br /> cost effectively implement the proposed work. <br /> Thanks <br /> Scott Forbess, P.E. (CA) <br /> Senior Principal Engineer <br /> ------------------------------------------------------ <br /> Direct: 916.637.8329 <br /> Mobile: 530.400.5092 <br /> From: Scott Forbess <br /> Sent: Friday,August 3, 2018 12:13 PM <br /> To: 'Iturkatte@sjcehd.com' <Iturkatte@sjcehd.com> <br /> Cc: 'mkith @sjcehd.com' <mkith @sjcehd.com>; 'Roger_Smith@oxy.com'<Roger_Smith@oxy.com>; Nicole Gotberg <br /> <NGotberg@Geosyntec.com>; 'Mike Cramer' <mcramer@greggdrilling.com> <br /> Subject: Issue with permit numbers WP0038566 and WP0038567 <br /> Dear Ms. Turkatte, <br /> This email concerns the current monitoring well installation work near the Simplot property in Lathrop, <br /> California under approved San Joaquin County Environmental Health Department (County) permit numbers <br /> WP0038566 and WP0038567. <br /> During our first monitoring well installation, the County inspector requested us to perform continuous grout <br /> placement. In our experience and that of our C-57 licensed drilling contractor, with installing monitoring wells <br /> all around California, we have never been asked by an inspector or regulator to place grout for monitoring <br /> wells in a single continuous lift. For monitoring wells constructed using PVC, we have always placed grout in <br /> multiple lifts of approximately 100 feet. This is done to prevent damage to the well casing (melting, warping, <br /> casing failure) resulting from the excessive heat generated by the exothermic process during grout curing. <br /> Because the monitoring wells at our Site are deep (— 300 feet), placement of approximately 250 feet of grout <br /> in a continuous manner produces a significant amount of heat, which has the potential for damaging the well <br /> casing. At the first monitoring well installed for this project, where grouting was required by the inspector to <br /> be conducted in a single lift, the well casing melted, damaging the well and making it unusable. This was <br /> despite the driller circulating water through casing for over 6 hours after the seal was placed. <br /> When we asked the inspector for the basis of the single lift requirement, he referenced Section 13.17 of the <br /> County's Well Standards (February 2005). Section 13 of the County's Well Standards for monitoring well <br /> installations does not require continuous grout placement. The Well Standards suggest that continuous grout <br /> placement is only required for the destruction of monitoring wells or exploratory boreholes (Section 13.17), or <br /> the installation of supply-wells (Section 4). The monitoring well installation requirements for sealing the upper <br /> annular space (Section 13.12) do not state that continuous grout placement is required. Additionally, the <br /> California Well Standards for Monitoring Wells do not require grout placement in a single continuous lift <br /> (California Department of Water Resources Bulletin 74-90, Part II Section 9). <br /> 2 <br />