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concentration the site could expect with the proposed development. No exact records or <br />information exist regarding the house's septic system exist. The Environmental Health Records <br />regarding the site's well mention the approximate location and size, but no specific data is <br />provided. The owners of the property do not have any records of the on-site septic system type, <br />besides knowing it is a 1,000 gallon septic tank. They have no records or knowledge of the system <br />type or age other than it was probably built pre -1960. They have no repair records. <br />5.4 Discussion of all proposed future on-site sources of nitrate to soil and groundwater and <br />the contribution of nitrate load from these sources to the project site: The future use of the <br />site, if subdivided, will continue to be residential and agricultural. The existing parcel would be <br />divided into a 2 acre lot and an unsurveyed remainder containing 37.7+/- acres. The proposed 2 <br />acres will be used for rural residential purposes. For residential use, the approximate flow rate that <br />is expected to be generated is between 50 to 70 gallons per person per day (Crites and <br />Tchobanoglous). Calculating nitrate loads conservatively, the value of 70 gallons per person per <br />day was used. This method is conservative as it does not include lateral dispersion or mixing of <br />groundwater. These factors of safety are additional to the County's factor of safety. The residential <br />homes contain 3 bedrooms total between each other. The residential homes are expected generate <br />an approximate of 240 gallons of wastewater per day total. <br />The average total nitrogen concentration of domestic wastewater is about 20-85 mg/L-N, <br />although 35-45 mg/L-N is a better approximation (Crites and Tchnobanglous). The value <br />selected for this site was 35 mg/L-N. <br />The site will experience a process of denitrification as the soil naturally treats surface material <br />through natural forms. Denitrification is a process that occurs when bacteria uses oxygen in the <br />nitrate (NO3) and release nitrogen (N2) into the atmosphere. Denitrification can be variable to the <br />type of soils, chemical properties, moisture content and other variables. Based on the sandy loams <br />on site and the high percolation rates, this site's soil has low levels of denitrification. It is expected <br />that a site with soil of these characteristics shall have approximately about 10-15% of <br />denitrification. The value used for this site was 15%. <br />5.5 Calculate mass balance of nitrogen loading considering all potential sources identified <br />using Hanztch/Finnemore equation: <br />Using the data mentioned within this report and the attached Soil Suitability Report the mass <br />balance of nitrogen loading for this site was calculated, this was done using Hanztch/Finnemore <br />formula. Based on the Hanztch/Finnemore equation the 2 acre parcel would contain a Nitrate Load <br />(Nc) of 9.97 mg/L-N. The site would be able to sustain flow required for the existing house, a flow <br />surpassing that amount could cause an impact to the site's nitrate load and surpass the maximum <br />contaminant level (MCL) of 10.0 mg/L-N for Nitrate in drinking water. <br />6.0 Discussion of nitrate loading results relative to proposed method of <br />wastewater disposal <br />6.1 Discussion of total nitrate impact from proposed project: There are possibilities that the <br />percolating effluent could affect water conditions. The Hanztch/Finnemore equation's factor of <br />lowers those risks, but no major additions should be made without an update to this report. The <br />results of well water indicate it has elevated levels of nitrates and may not be a suitable source of <br />water for a new development. An alternative potable water supply that can provide a consistent <br />E <br />