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The results for the deep percolation at the site were 0.41 irl/y The nitrate concentration is estimated to be about 1 mg/L-N. (Hantzche andiF'innemore, 1992). 5.3 Description of all current on-site sources of nitrate to soil and groundwater and the contribution of nitrate load from these sources to the project site: The sources of nitrates would be from a septic system in use by an existing parcel for residential uses. The septic system was accounted for when determining the approximate nitrate concentration,the site is expected to produce minor increase of nitrates with the proposed development. 5.4 Discussion of all proposed future on-site sources of nitrate to soil and groundwater and the contribution of nitrate load from these sources to the project site: The future use of the site will remain consistent. It will continue to be used as an orchard. Currently there are no new improvements being proposed for the site. The existing site could include which we expect to see 350 gal/day. Each site can provide 350 gal/day. The site is accounting for a factor of safety. Therefore, the approximate values used should be doubled. This method of determining nitrate loads is conservative on its own,the value of gallons per day was used in the calculations was 700 gal/day. This method is conservative as it does not include lateral dispersion or mixing of groundwater. These factors of safety are additional to the County's factor of safety. The site is not expected to grow,thus having no significant impact on both 22.7 proposed acre parcels. The average total nitrogen concentration of domestic wastewater is about 20-85 mg/L-N, although 35-45 mg/L-N is a better approximation(Crites and Tchnobanglous). The value selected for this site was 40 mg/L-N assuming this site shall experience a larger concentration. The site will experience a process of denitrification as the soil naturally treats surface material through natural forms. Denitrification is a process that occurs when bacteria uses oxygen in the nitrate (NO3)and release nitrogen(Nz) into the atmosphere. Denitrification can be variable to the type of soils,chemical properties,moisture content and other variables. Based on the sandy loams on site and the high percolation rates, this site's soil has moderate levels of denitrification. It is expected that a site with soil of these characteristics shall have approximately about 10-15% of denitrification. The value used for this site was 10%. 5.5 Calculate mass balance of nitrogen loading considering all potential sources identified using Hanztch/Finnemore equation: Using the data mentioned within this report and the attached Soil Suitability Report the mass balance of nitrogen loading for this site was calculated, this was done using Hanztch/Finnemore formula. Based on the Hanztch/Finnemore equation this 22.68-acre site would contain a Nitrate Load (Ne) of 2.40 mg/L-N. 6.0 Discussion of nitrate loading results relative to proposed method of wastewater disposal 6.1 Discussion of total nitrate impact from proposed project: There are possibilities that the percolating effluent could affect water conditions. The Hanztch/Finnemore equation added to the County's factor of safety of two diminish those risks, but no major additions should be made beyond the proposed improvements mentioned previously without an update to this report. 3