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In December 2000 we placed well BM-13 to test the surface water of the east side of Grant Street This well was placed within 5 feet of wells BM-8 which was 65 feet deep Well BM-13 was 45 feet deep Groundwater Concepts The Hydraulic Conductivity of the groundwater was tested on April 30, 1993 in wells BM-4, BM-5 and BM-6 The conductivity was found to be 2 94 feet/day The depth of the water table was 53 feet and the soil unit was a silty sand This sand extends from the western well BM-9 to lust beyond wells BM-8 The average gradient for this site is to the northeast at 0 00345 and the velocity is calculated to be 0 07203 feet per day During any quarter the water will travel about 6 3 feet Of all the activity at this site, two occurrences seen to present a problem we are trying to understand The fact that boring HP-2 was dry at 45 feet and did not encounter water until we reach 55 feet and that the water in boring B-3 did not have any MtBE at 39 feet Boring B-3 was used to find out if any MtBE was leaking from the tank B-3 encountered MtBE in its water at 50 feet and 60 feet The fact that boring HP-2 did not encounter water at 55 feet below the actual water table The fact that no water was flowing for 10 feet indicated that the water had encountered a soil unit which could not transmit water, the unit was a clayey silt When we drilled . to a depth of 55 feet we encountered water which was contaminated with TPH and BTEX We did not test this water for MtBE since the county did not require that test at that time The soil units which carred water at this level were fine clayey sand lenses about 2 feet thick The water table in 1995 was 46 feet below the surface and at present is 35 feet This rise in the water table caused the ground water flow to shift at the ARCO Station at the comer of Stanislaus Street and Charter Way to a more southerly direction However, we believe that the water deeper than 55 feet is still flowing to the northeast We believe this is occurring because the BTEX and MtBE levels in B-3 increased with depth We also believe that the water entering at the Sun u _a Gardens building is coming from a site or sites west of our site There are two known tank leaks to G` 4 the west, one at 641 East Charter Way and the ARCO station The levels of MtBE in well BM-3 have been present since January 1998 and are present at this time When we drilled boring B-3 we tested the water as described above and found no MtBE at the surface of the groundwater but it increased with depth This increase indicated that the contaminated water was coming from another source and it was the same scenario we encountered at HP-2 where the water enters this site at 55 feet In our activity report dated June 30, 1995, we reported that there were two plumes involved at this site One entering from the west and the other from our site We conclude then and still believe this is the case We would appreciate a revision of this report and look forward to hearing from you soon