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Destruction Report 5 C& tional Sales Inc. May Cardno May 26,6,201 2015 Shaping the Future made available for the SJCEHD to inspect and to verify that the well had been properly destroyed. The grout was finished to grade and resurfaced to match the surrounding surface completion. Wells Abandoned by "Popsicling" Technique MW4, MW6, and MW7 were destroyed by the "popsicling" technique because overdrilling was not possible. MW4, and MW6 were sandwiched between two newly installed pipelines that were not present at the time of the well's installation and MW7 was inaccessible to a drill rig due to the construction of a building over the top of the monitoring well. Popsicling began by using an air knife to remove the soil encircling and exposing the well box casing and grout column. All the exposed well components were removed from the air knifed excavation. Then a special driller's tool was threaded into the remaining well casing to enable the removal of the remaining well casing. In the case of MW4 and MW6 the casing was removed with the conventional drill rig, but MW7 required the use of a tripod and winch due to the access limitations. Once the component parts of the well were removed, the borehole was backfilled with a neat cement grout slurry mix from the base of the annulus to the surface using a tremmie pipe. Any groundwater displaced to the surface during grout installation was pumped out of the excavation, collected, and collected into drums for proper disposal. This water was made available for the SJCEHD to inspect and to verify that the well has been properly destroyed. The grout was finished to grade and resurfaced to match the surrounding surface completion. Wells Abandoned by Pressure Grouting Technique Groundwater monitoring well MW5 was destroyed by pressure grouting according to the following procedure. Prior to destruction, a 24-inch diameter hole was cut into the concrete. The well box and locking plug were removed and an air knife was used to remove a 24-inch diameter column of soil encircling the casing to a depth of approximately 36 inches. The well casing was cut off 30 inches below grade and was removed. A specialized pressure-grouting tool was affixed to the well casing to deliver and emplace a neat cement grout slurry under pressure into the well. The slurry was pumped under pressure into the remaining casing until the slurry was injected into the sand filter pack and filled the remaining casing. Once grout extended to the top of the well casing, air pressure of 25 PSI was applied to the well casing for approximately five minutes. Additional grout was poured into the top of the well casing as necessary. MW5 was deemed successfully destroyed when a pressure of 25 PSI was maintained for five minutes with the grout dropping less than one foot. Following the pressure procedure, additional grout was made to overflow into the excavation and form a minimum 24-inch diameter "mushroom cap" like seal, with at least 12 inches of neat cement grout poured 6 inches above and 6 inches below the top of the cut-off casing. Any remaining soil voids were backfilled compacted and resurfaced to match the surrounding surface completion. Well Destruction Logs The California Department of Water Resources (DWR) requires that all well installation and destruction activities be reported. Upon completion of well destruction activities, Cardno and Gregg prepared DWR well destruction logs and submitted them to the DWR office in Sacramento. Copies of the submitted logs can be found in Appendix A Waste Disposal The investigation derived waste (IDW), including soil cuttings, groundwater, and decontamination water generated during well destruction activities were contained in DOT approved 55-gallon steel drums and temporarily stored on site in the existing remediation compound. The IDW were profiled and found not to contain contaminants above laboratory method detection limits. The analytical results for IDW can be found in Appendix B. Since the IDW was sampled, analyzed and determined to be free of www.cardno.com