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IRM Prove-Out Reports -4- 29 August 1991 DDRW, Tracy 6. Pages 4 and 13. The extraction and injection wells were installed with a gravel feed pipe and a sounding tube in the annular space. The rationale for placement of these pipes was not discussed. It is assumed that the gravel feed pipe was a precautionary long-term measure installed so that additional filter pack may be placed in the annulus in the event that the well produces excessive gravel . It should be noted that if the filter pack is properly designed and the well adequately developed, the extraction wells should not be expected to "sand-up" prematurely. The rationale for the placement of the sounding tube was not presented, but is assumed that it will be used to obtain water level measurements in the annulus so that well losses can be determined. The report should have provided more discussion on the rationale behind the design of the extraction and injection wells. 7. Pages 7 and 15. The report states that the transmission line was compacted to 90 percent of maximum density. However, the report does not indicated how percent compaction was determined, that is, through the use of a nuclear gage or by the sand cone method. If these tests were performed the results were not provided in the report. In addition, the report does not indicate whether the backfill in the injection well and storm pond diversion lines had the same compaction criteria as the transmission line. In my inspection of the IRM on 11 July 1991, I observed that the backfilled storm pond diversion line was not level with the adjacent land surface and that it had settled significantly. Therefore, an inadequate amount of backfill may have be used for the diversion line, 90 percent compaction may have been an inadequate design criteria or 90 percent compaction may not have been achieved per the design specifications. If the compaction of the backfill in the pipe line trenches is inadequate, this may lead to premature pipeline breaks, needless pipeline repairs and shutdowns of the IRM. 8. Page 16. The report states that the location of MW-3 was changed from that in the original construction plan and that the new location was okayed during an inspection by the State in January 1991. It needs to be clarified that the well had already been installed by the time of the inspection on 11 January 1991. GEOLOGIC WELL LOGS REPORT 1 . Page 8. The report states that all of the monitor wells were logged geophysically. Because some of the monitor wells for the extraction and injection system are very shallow and are in a cluster with deeper monitor wells, it seems that geophysical logging of these wells is redundant. Therefore, I recommend that only the deepest wells in a cluster be geophysically logged for future well installations. 2. The report provides the as-builts for each extraction, injection and monitor well in Appendix B but does not summarize the well construction information in a table. In the future, all well construction information should be summarized in table form for easy reference. 3. Figure 1. The plan view map of the cross-sections needs to be revised. This map does not have a horizontal scale, does not depict any other wells at the site nor does it depict the site boundaries. This map cannot be used to determine distances from one point to another.