SITE INFORMATION AND CORRESPONDENCE

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Central Valley Regional Water Quality Control Board March 6, 1998 Page Two Grout arrived at approximately 2:30 pm. on Friday afternoon. Four cubic yards of grout was ordered, slightly greater than double the calculated hole volume. The grout was pumped from approximately 54 feet to 10 feet below ground surface and a second load of grout was ordered. It was at this time that Mr. Roe voiced his objection to the abandonment process,citing Section 4.7.4 of the PHS/EHD Well Standards and stating that the well must be abandoned in one"continuous pour". Please note that Section 4.7.4 requires that the"grout shall be applied in one continuous process". Also note that neat cement does not set for seven to nine hours from placement. It is our position that adding subsequent loads of grout within the time frame prior to the cement setting constitutes a continuous process. It is not uncommon for wells being grouted or abandoned to require a quantity of cement greater than one load. In this case the well eventually required nine yards of neat cement to fill it to the surface. Water Development abandoned two wells in San Joaquin County that required over five separate loads of grout to fill. In these cases no objection was expressed by PHS/EHD,as the process was continuous. At this time,Water Development removed the tremie pipe from the well in preparation to pull the casing. It was imperative that the casing be removed at this point in order to prevent it from becoming differentially stuck. It was determined that the top portion of the borehole was not prone to sloughing and that the tremie could be reinserted into the grout mass without difficulty. Leaving the casing in place could potentially prohibit cement from filling some of the void space outside the casing. Mr.Roe stated that once the tremie pipe was removed,the grout process was no longer valid and he would not sign off on the abandonment. Attempts were made to assure him that the subsequent grout would be tremied in place. Note that the County Well Standards call for the tremie to be raised as grout in pumped, Section 4.7.2.1. His response was that it makes no difference what we do because we have already made too many mistakes for him to sign off on the abandonment. Mr.Roe stayed for the removal of the casing.At 4:00 p.m.he announced he was leaving. He was very angry. He was informed that the additional grout had left the plant and would be there shortly. He left. The additional grout arrived at 4:15 p.m.Tremie was placed to 15 feet,5 feet beyond the top of the grout and 5 additional yards of grout were placed. Approximately 2.5 yards of the second pour was required to fill the excavation around the well head. In his letter Mr.Roe notes that the intent of Section 4.7.4. is to eliminate"potential for joints,mixing of grouting materials with borehole matrices,and bridging. Please note that the initial load of grout had not set, so there is no joint between loads. The tremie pipe was reinstalled into the grout mass and the second load pumped so there was no mixing of cement and matrices. As the top ten feet of the borehole was stable(three of that ten feet had been excavated prior to removal of the casing)there was no danger of caving or bridging. Mr.Roe's objection to the removal of the tremie pipe and the casing are unfounded as these actions do not violate the intent or the literal interpretation of Section 4.7.4.or any other sections of the County Well Regulations. The concerns voiced at the time by Mr.Roe,namely that the removal of the tremie pipe would leave us with"no control of the borehole with regard to collapse and potential bridging",were also unfounded. Neither occurred as he witnessed. It is our position that Water Development and Emcon executed the decommissioning of 17A1 in accord with the regulations and the work plan. Water Development has been performing this type of work since 1949 and have completed over 200 drilling projects in San Joaquin County alone and literally thousands throughout the west.As one of the largest water well drilling contractors in the state we have a vested interest in adherence to high standards in construction and protection of water resources. We appreciate your consideration of our letter. Should you have any questions or require further information,please call me. Respectfully: Don Motsko Contracts Manager