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Three drinking water wells have been completed in the project area. All three are finished in either the St. Lawrence of the Franconia aquifer (well logs are attached) at depths of about 178 feet. Nitrate concentrations are less than 8.7 mg-N/l (test results are attached). The deep wells should have a low probability of future nitrate contamination based on findings reported from other studies. Several steps could be taken to minimize the risk of future well contamination. Wells could be finished in the bedrock aquifer and lawn fertilization could be controlled. Lawn fertilization could theoretically supply more nitrogen to the groundwater than onsite systems. For example, an average residence of 3.5 persons using 178 liters/cap/day (45 gpcd) with a nitrogen concentration inseptic tank effluent of 48 mg-N/l (ammonia + nitrate-nitrite) would produce 8.7 kg of nitrogen/residence/year. Alternatively, if residents were to apply the recommended nitrogen fertilizer dose to one acre of lawn within their 2.5 acre lot, they would apply 89 kg of nitrogen compounds per acre. Although some of this fertilizer would be taken up by vegetation, a percentage would be washed down into the subsurface (Baker and Johnson 1981, Gupta et.al. 1982). Therefore, not only should onsite system maintenance and operation be closely observed, but fertilization practices should probably be controlled as well. . . 6. The wastewater flows and potential nitrate concentrations for the commercial/light industrial development is rather vague. It is understood that a more detailed hydrogeologic analysis would be required for a state Waste Disposal System permit. When commercial development plans reach a more defined stage, the necessary studies will be conducted. . . , 7. This item has been added to Section 2. ! . 8. "Book" values for export coefficients were selected with care to relate to the case at hand. Values were selected from a literature review that listed over 158 different values for phosphorus export coefficients (USEPA 1988). Literature values were selected from areas that would be similar to Northfork settings (sandy loam soils, 78-188 cm/yr precipitation, row crops and non-row crops, etc.). One way to check the modeling approach and the validity of "book" values for export coefficients would be to sample the lake phosphorus concentrations and compare the actual lake concentrations with the predicted phosphorus concentrations. A Lake Itasca phosphorus sample was collected on 28 May 1986. The laboratory analysis for total phosphorus was 0.02 -78- l