SITE INFORMATION AND CORRESPONDENCE

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between testing under static conditions and under active pumping. Margaret distributed 5 packets of information regarding the 8 sites. The information shows their well sites, soil data, and concentration boundaries. She stated that as of 4:30 p.m. yesterday they were still pumping the water into the storm system. Marc Bridges said they are not pumping. It was noted that Contractor was developing the wells that could take about five to thirty minutes. They are not putting contaminated water into the storm system. Margaret stated the water should all be contained until it can be determined whether or not it is contaminated. Tony Martin agreed that Kleinfelder could do a pumping analysis. Mike Conrad stated he will need an analysis to determine what pumping rate can be used. Other alternatives to dewatering were discussed. Tony Martin suggested directional drilling is a possibility. He also recommended they sample all wells to eliminate those we know are contaminated. Michael I. noted that this would not provide any real degree of comfort, as it only tells us contamination levels under static conditions. Margaret stated that the Shell station has stopped the use of MTBE, but is now using another substance that may also cause concern. Marc B said that he has 4 wells pumping 50 — 75 gallons per minute each at the bore pit. At this time, the volume is what they expected. There are 189 wells to be done on the project altogether. Marc noted that the groundwater levels are approximately at 8' to 10' below grade along the pipeline. Another possibility presented is a groundwater treatment system such as a carbon filtration. It has been used on other projects. Mark M asked about trench excavation as was used on the Westside Sewer Interceptor Project. Marc B stated they decided to use dewatering wells because contractor was concerned with getting the soil dry enough to put back in. He said they could look at the option of not using dewatering wells once they know how much water to expect. There was discussion on going to more shallow wells, but it was questioned whether that would provide adequate dewatering.