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Nw = 45 mg N/L d = 50% as determined from the soil chemistry on the backhoe test pit samples. R = 2.21 in/yr from Table 3 above. Nb = Assumed to be 0.1 ppm NO3-N 1.29 in/fir ((45 mg N_ /L) (1 - 0.50) + (2.21 in/yr x 0.1 mg/L) Nr = (1.29 in/yr + 2.21 in/yr) Nr = 8.4 ppm as nitrate -nitrogen (NO3-N) or 37.3 ppm as nitrate (NO3) EFFLUENT DISPOSAL PARAMETERS A filter bed disposal structure will be installed for this project, as illustrated on the attached plans. The filter bed dimensions are 20 ft E -W and 40 ft N -S = 800 sf. Although a 1,200 gallon septic tank is required, a 1,500 gallon tank is specified to be installed on the east side of the new house, adjacent to the Master Closet. In addition, the Pool Cabana will have a toilet and sink. It is proposed to install a 1,200 gallon septic tank adjacent to the east side of the Cabana. A tightline from this tank will transport effluent north and connect to the second compartment of the 1,500 gallon tank. Effluent gravity flows from this 1,500 gallon tank to a distribution box (D -box) to be equally distributed between three leachlines. The primary and 100% replacement areas are denoted on the Site Plans. Since it has been documented that the water table has been at 9 ft below grade in the past, there must be an 8 ft separation distance between the soil -effluent interface and the highest anticipated depth to groundwater. Consequently, 1.5 ft of soil has been imported over the entire north half of the subject Parcel. The influent lines must come through the footings of the structures for connection with the two septic tanks. The tanks must be installed with the top of the tanks 4" above the new existing grade. This will allow sufficient grade to maintain the 8 ft separation distance as illustrated on the Elevational View plans found in Appendix E. CONCLUSIONS AND RECOMMENDATIONS NLS§ 4.2. The shallow subsurface soils underlying the subject property where the filter bed is to be installed, reveals a sandy loam soil material. A high degree of denitrification was measured in the soil chemistry test results. NLS§ 4.1. The nitrate loading calculations show the resultant effluent from the entire subject Parcel will theoretically possess a concentration of approximately 8.4 ppm as nitrate -nitrogen, which is under the Maximum Contaminant Level (MCL) of 10 ppm. NLS§ 4.2. All on-site wastewater treatment systems (septic systems) will eventually fail. A reasonably long lifespan of the primary disposal area for this project can be expected based on the perc rates obtained and the components of the septic system. IZ Chesney Consultin;