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SECOND QUARTER 2003 GROUNDWATER MONITORING REPORT AND ADDITIONAL ASSESSMENT REPORT JAMAR OIL DISTRIBUTION JUNE 2003 The slug (bailer)was then removed and the water level recovery was monitored using a downhole data logger. With the aid of Waterloo Hydrogeologic, Inc. (W H) Aquitest software, a Bouwer and Rice evaluation was conducted to determine aquifer hydraulic conductivity (K) around the boreholes and a pump rate/yield for a limited step drawdown pumping test. The collection of the water level recovery measurements was made utilizing continuous recording pressure transducers on to a datalogger. The data was downloaded into the WHI Aquitest software,the information was graphed and estimates of hydraulic conductivity were made. A virtual total recovery of groundwater in the wells was observed during these tests, with MW-1 and EW-I similar in recovery/conductivity. The MW- 4 slug test data is not included in this report due to a software malfunction or corrupted spreadsheet. The horizontal hydraulic conductivity (K) values for MW-1, and EW-1 were 0.104 and 0.131 ft/day, respectively. The slug test data is included in Appendix D. Extraction well EW-1 was used as the pumping well for the aquifer performance test (pump test) and the hydraulic conductivity of this well was used in estimating the water level fall rate at various pumping rates. The pumping steps for this test were conducted at 0.5, 1, 2, 3 and 5 gallons per minute(gpm). The optimum pump rate with sustained yield for this well was determined to be approximately 2.5 gpm; and the 3 gpm hydrodata from EW-1 was used for estimating hydraulic parameters. A standard drawdown semi-log plot was prepared with the aid of the WHI Aquifer Test software. There was no water level response (influence) on monitoring well MW-3 during the test, (See Appendix E). A number of different analyses were conducted on the pump test; the best results came from the Cooper-Jacob time drawdown test (modified for unconfined conditions) for evaluation of water level measurements. The aquifer/saturated zone parameters obtained from this test were: Transmisssivity(T) 1.47E+2 ft2/day Hydraulic Conductivity (K) 1.05E+1 ft/day A value of 0.1 or 10 percent was used for the specific yield/storativity value. The material that the groundwater was being pumped from was assumed to be the unconsolidated silt to silty sands described from the boring logs of EW-1. A Storativity/Specific Yield of 4.1 from an unconfined aquifer was considered reasonable for the purpose used. A zone of influence was observed during the step tests on MW-1, MW-2 and MW-4, which are all less than 85-feet from EW-1, but not on MW-3, which is approximately 150-feet from EW-1. The results from MW-3 are not unexpected considering the small amount of water removed and the low yield, low transmissivity groundwater zone. Graphs of the influence recorded in MW-1, MW-2, MW-3, and MW-4 are included in Appendix E of this report. 9