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resultant nitrate—nitrogen concentration of 5.6 mg-N/L, which falls within an acceptable range, within the 10 mg-N/L drinking water criterion. I agree generally with the methodology, assumptions and calculations presented by Chesney with the exception of the value for rainfall recharge. The study uses an assumption of 13 inches per year for rainfall recharge (R value), with no supporting rationale or reference. This value is nearly equal to the average annual rainfall for the project area, which does not seem reasonable or realistic. Rainfall recharge is a critical factor in the application of the Hantzsche/Finnemore methodology, which is pointed out in the "Discussion" section of the literature which is listed by Cheseny: "5. The curves of Figures 1 and 2 show the strong influence of the rainfall recharge component on the resultant nitrate -nitrogen concentration. The application of the methods presented in this paper and the reasonableness of the results are, therefore, limited by the accuracy with which the rainfall recharge fraction can be estimated or determined by the user. For best results, the user should perform a thorough water balance analysis using techniques such as those developed by the USDA Soil Conservation Service (1964) or Thornthwaite and Mather (1955), or other information based on local studies. " (Hantzsche and Finnemore, 1992) I recommend that the consultant conduct and provide appropriate supporting analysis for the estimation of the rainfall recharge factor used in the nitrate loading calculations, and resubmit for follow-up review. Since the nitrate loading study makes reference to the incorporation of stormwater retention, I would suggest the consultant may wish to follow the modified methodology described in Attachment A.