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h Mr. Jeff Van Slooten Page 2 last two sentences of the second paragraph on page B-1 imply that the Cooper-Jacob (not "Jacob-Cooper") method is solely applicable to pumping well data. While this method can be used to characterize aquifer parameters at the pumping well, the calculated value of transmissivity (T) may then be only an estimate of the true aquifer value. In order to calculate the T that is most representative of the aquifer being pumped, it is necessary to analyze data collected from observation wells. In order for the Cooper-Jacob method to be appropriately used, the value of u must be less than or equal to approximately 0. 01. This criterion is achieved at relatively small distances from the pumping well and/or when the time since pumping began is sufficiently large. It is stated at the bottom of page B-1 that this criterion is " . . . actually true of the aquifer system" at the site. The meaning of this statement is unclear. If it was meant to indicate that sufficiently late data from the pumped wells were analyzed via this method, then the statement is false. Although data from the pumping of DSW-4B, -4C, and -4D were analyzed with this method, only late time data from the pumping of DSW-4B (as seen on Figure B-1) appears to be well suited to Cooper-Jacob analysis. A discussion addressing how the shapes of data plots for DSW-4C and -4D do not conform with Cooper-Jacob analysis and associated implications with respect to the conceptualized hydrogeologic system must be included in this section in order to consider the aquifer test data to be fully analyzed. The denominator of Equation B. 2 must be defined. Although this equation is derived from a partial differential equation, the "change in drawdown" over one log cycle of time is commonly expressed as " & s" . Equation B. 2 must be adjusted to reflect the most common nomenclature. Leaky Aquifer Analysis It is noted on the bottom of page B-2 that the Hantush (1956) method of aquifer analysis permits the calculation of horizontal hydraulic conductivity (K) and specific storage (Ss) of the pumped aquifer, as well as the vertical hydraulic conductivity (K' ) of an overlying leaky aquitard. However, rather than Ss, this method directly allows for the calculation of aquifer storativity, or S . Although these two terms are related (Ss equals S divided by aquifer thickness) , they cannot be used interchangeably; Ss represents storage characteristics of a specific type of geological material, while S refers to the storage characteristics of the particular aquifer in question.