Laserfiche WebLink
Sent- By: RWQCB; 2553439; Sep-6- 9:46AM; Page 314 <br /> HW9101 Harlan Street, <br /> Suite 210 <br /> PW. GEOTRANS <br /> Westminster, Colorado <br /> 80030 <br /> A TETRA 'rEC.H COMPANY 303-426-7501 FAX 303-426-7780 <br /> August 25, 2000 <br /> Ms.Jessica Ilardy <br /> California Regional Water Quality Control Board <br /> 9443 Routier Road, Suitc A <br /> Sacramento, California 95827 <br /> Subject-, Response to Comments on Monitoring Well Abandonment Work Plan, <br /> Leprino Foods Company 'Tracy Plant; IISI GeoTrans Project No.L070 <br /> Dear Ms. hardy: <br /> On behalf of Lcprino Foods Company(LFC), HSI GcoTrans has prepared the following <br /> responses to comments received in your letter dated August 11, 2000. <br /> C:ommenl I - Will the monitoring well casing be overdrillcd or perf(wated prior to grouting? <br /> Response - Section 6 of the San Joaquin County Environmental Health Well Standards <br /> (undated)describes destruction of wells. Part 6.3.3 of this section states "If there <br /> is no annular seal,or the integrity of the seal or the well is unknown, or the well is <br /> gravel packed, the casing shall be perforated upward beginning with just above <br /> the filler material to the surface. Grout shall be applied above the approved filler <br /> material in such a manner that the grout shall be forced out of the perforated <br /> holes, forming a barrier to the vertical movement of water." <br /> Because both wells have bentonite sanitary seals that are intact, and both are filter <br /> packed to immediately above the well screen, which lies ittunediately below the <br /> bentonite seal, the well screen will effectively act as perforated casing, allowing <br /> grout sealant to permeate the filter pack over the entire screened length of the <br /> well. The grout mixture (described in Response to Comment 4)will be of <br /> sufficiently low viscosity and solid content to allow permeation. <br /> C.'ommeni 2 - The work plan states that the wells will be pressure grouted;however, it dues not specify the <br /> procedure to he employed The grout should be tremied from the bottom of the casing to ensure <br /> that bridging does not occur. <br /> Response - LFC agrees. The grout will be Iremied from the bottom of both wells in <br /> accordance with Section 6.3.4 of the Ran Joaquin County Environmental health <br /> Well Standards. <br /> Comment 3 - The surface completion and the uppermost portion of the casing and annular seal should be <br /> removed and backfilled with clean fill and paved(if needed). <br />