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I I I I I I I I I I I I I I I I I I I difference in the water level. Valley Pump increased the pumping rate to 22 gpm and the test wells were monitored again for 15 minutes with no change in the water level. At this point WRC determined that the pumping test was not yielding conclusive results, so pumping was discontinued. Due to the failure of the pumping test to yield positive results, it was necessary to estimate the properti es of the aqui fer by other methods. Sieve analysis was performed on soil samples from 4 of the test well s and an average permeabil ity of 106 gpd/ft2 was determined. Based on a length of 1200 feet (the maximum width of the three block area in the northeast part of town) and lowering the water table by a maximum of 4 feet, the interception rate required woul d be 0.73 cfs. Thi s is the mi nimum rate that the dewateri ng system will be based on. 3. Alternative Solutions , -' Two different means of lowering the water table were investigated: a) system of well poi nts and b L subdrai n perforated pi pe system. The investigation considered the engineering and construction concepts as well as installation plus operation and maintenance costs in developing the project recommendation. a. Well Points WRC determined that in order to drop the water table a depth of two feet using well points would require approximately 60 well points along (spaced at 20' along a 1200' line). The initial cost of this system is estimated to be from $50,000 to $70,000. O&M costs per year were estimated at $50,000 a year, including pump rental and normal maintenance. b. Subdrain system (gravity flow) A gravity subdrain east-west perforated system consisting of three parallel pipes connected to a sol id north-south -15-