Laserfiche WebLink
a :�t tsr t�tcoti 6-16-98 1:54PM : EMCON SACRAMENTO # 4/ 6 <br /> Mr. Ronald Rowe I Project 20C42-001.026 <br /> .lune 12, 1998 <br /> Page 2 <br /> i <br /> i <br /> A second firm tag of the grout indic+d the level was approximately 10 feet bgs. Tremie <br /> pipe was replaced to 15 feet bgs. Tho grdut resumed at 4:20 P.M. An additional 5 cubic <br /> yards of grout were placed to gent d surface. This quantity included approximately <br /> 2.5 cubic yards to fill the void from Oe concrete pad wellhead. <br /> I <br /> I <br /> ISSUES <br /> I <br /> Prior to and after placement of the infour i tial focubic yards of grout, several issues were <br /> raised. These issues and respective responses are presented as follows: <br /> • The plan to remove the easiTg and tremie grout the borehole was a significant <br /> deviation from the proposed rtoration and pressure grout method. <br /> — The well driller's log ind" ated that the well had a 10-inch-diameter casing, <br /> but the actual casing wa 8-inch diameter. The wellhead was removed to <br /> determine if a 10-inch-diameter casing was present as an outer sleeve, <br /> enclosing the observed 8-i.nch-dianmcter casing. No other casing was present <br /> and the annular space was]open to the formation. EMCON verbally notified <br /> you and Gail Wiggett o these observations prior to the well grouting <br /> activities and indicated at this time that we would remove the casing in the <br /> interval to 55 feet to me qt the intent of Section 13.17.6 of the PHS/1r1-ID <br /> Well Standards. Removing thecasing allowed direct contact of the grout <br /> with the formation over thf inta] grouted. <br /> • The grout required at a groundwater contamination site in San Joaquin County <br /> consists of either neat cement] cement containing up to 4 percent bentonite, or a <br /> 100 percent bentonite grout. j <br /> - The initial grout order wa� a 10-sack mix, consistent wish state standards. <br /> Upon arrival of Ron Rowe and discussion of the grout mix, the grout <br /> requirements were discuss4 d and the grout order was changed to neat cement <br /> consistent with the county�egmrements. <br /> • Grout must be placed in a continuous pour to 5 feet bgs. <br /> — 1-he grout was continuously placed to 5 feet bgs as determined from the <br /> mark on the trermpipe a'd tagged firmly at 10 feet bgs. Therefore, grout <br /> placement was to 5 feet bg,- When the second batch of grout was placed,the <br /> tremie pipe was set at 15 f et bgs, providing a 5-foot overlap with the level <br /> SACUJ1P7010C4210(:420012.6AP-98khc1Cl EflICOfI <br /> Rev.0.Ame 12.1998 <br /> I <br />