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Page 9 is Monxtonng Well #4 0 . 5 1616182022 0 2 4 6 8 1011 1111 11 1212 1 4 3 0 0 00 0000 00 00 0 0 1 1 4 1 4 - 10 5 1 0 0 0 0 6 0 3 5 5 5 Depth from - 1 5 Surface -20 -25 - 30 �_i-i ■.■-i_i.i-■.iri.i.i.i.i.i_i.i.■.i_' - 35 -- The gap at 18.30 is due to a lack of data for that time Conclusions and Recommendations Soil samples collected during the installation of Monitoring Well 4 and groundwater samples collected for all of the monitoring wells had no TPH-g or BTEX detected from the laboratory analysis Groundwater gradient at 890 North Main Street remains sloped towards the southwest, which is consistent with groundwater gradient measurements taken in 1987, 1988 and 1990 by other consulting firms. Groundwater levels have continually dropped at the site according to the four measurements taken from 1987 to 1991, from 13 feet BGS in 1987 to 29 feet BGS in 1991 One municipal well and four private wells were found within 2,000 feet of the study property, using a State of California list of water wells kept by the Department of Water Resources, Groundwater and Climatology Division The municipal well, with a pumping capacity of 700 gallons per minute, is the nearest well, approximately 800 feet southwest of the study property. The municipal well water's average depth is between 33 and 35 feet BGS, which is at least 4 to 20 feet below the water level measurements at the study property. The four monitoring wells on the study property appear to be to the same aquifer. Data from the pump test show a direct response to an abrupt drawdown in Monitoring Well 4 in Monitoring Wells 1, 2 and 3. Response was reverse (or mounding) in Monitoring Well 2, but that may be due to a natural barrier between Monitoring Well 2 and 4. The drawdown may have caused the groundwater to nse Parker Environmental Services 4185 Rialto Court Pittsburg CA 94565-6116 Phone (510) 439-1024 Fax (510) 439-2566