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The interpretation of the step drawdown test is provided in Figure 1 This graph is a double <br /> logarithmic plot showing the water level drawdown versus the discharge rate The step <br />' drawdown test data points are represented by the four filled circles <br /> Drawdown in a pumped well is made of two components aquifer loss (drawdown caused by <br /> resistance to laminar flow in the aquifer) and well loss Well loss is the drawdown required to <br />' overcome the resistance to turbulent flow in the vicinity of the well, through the screen and <br /> filterpack, and within the well if the pump is tightly fit Anisotropic aquifer stratification can also <br /> 1 <br /> affect this relationship The total drawdown is represented by the following equation <br /> D = BQ + CQ" <br />' where D = drawdown in the pumped well in Ft , <br /> Q = flow or discharge rate in GPM, <br /> BQ = aquifer loss, <br /> CQ' v well loss, <br />' and B, C, and P are coefficients <br />' Using the data from the step drawdown test- <br /> P = 22219, <br /> B = 0 5886, <br />' and C = 0 6632 <br /> IThe curve defined by this equation for the step drawdown test data is shown on Figure 1 as the <br /> line passing through the step drawdown test data (solid circles) Dewatering effects are not <br />' considered to this interpretation <br /> A nominal flow rate of 1 5 GPM was selected for the constant rate test <br /> 1-12OGEOL A GROUNDWATER CONSULTANCY <br />