Discussion of "Simple Method for Confined-Aquifer Parameter Estimation"

Identifying aquifer parameters is fundamental for the develop-ment of mathematical models to predict the water and contami-nant flow in an aquifer. Consequently, any reliable method fortreating data from pumping tests—that allows to evaluate the ac-tual behavior of natural aquifers—may represent a valuable toolin groundwater management. As a matter of fact, the statement ofCarrera and Neuman ~1986!, ‘‘while the mathematical and com-putational aspects of the prediction of an aquifer response toplanned stresses are reasonably well developed, the question ofhow to choose appropriate parameter values for a specific aquiferhas not been yet completely resolved,’’ still holds. In such a con-text, the criterion proposed by the author is quite attractive inprinciple since it is based on data taken from short durationpumping tests. In fact, this type of field tests can be more easilycarried out since their execution interferes with the functioning ofwell fields in the least possible way. Such an aspect must not beunderestimated as in most cases major obstacles for a comprehen-sive field-test campaign are due not to budget limitations, but toconstraints deriving from the users’ needs that must be fulfilled.In fact, since during pumping tests the discharge withdrawal, Q,can be much less than users’ demand, when in the pipe systemstorage capacity is scarce, crisis scenarios may occur.The discussers’ specific interest in the paper derives from theirexperience in the field of pumping tests in confined aquifers, butrelating to quite different experimental conditions ~Bellin et al.1995; Brunone et al. 1998, 2000!. Precisely, main differences re-gard the value of Q along with the distance, r, between the pump-ing well and the observation wells, both much smaller than in thetests considered in the paper. Thus, data by the discussers mayallow to further check the method proposed by the writer.Since 1994, AST, the Water Supply Company of Recanati ~I!,has supported an extensive hydrogeological survey in the lowerpart of the Potenza river valley in the central Italy region ofMarche ~Fig. 1!. The main objectives of this survey are the censusof drinkable water production wells, as well as the developmentof a global numerical model for the management of groundwaterresources. In the preliminary phase of such an activity, local-scalegroundwater numerical models—based on the results of pumpingtests—were built for the existing well fields in order to define therelated protection area. In Table 1 of the original paper, localhydrogeological information concerning the three operating well-fields are reported. In Table 1, as an example, the values ofs