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100 gallons per day(gpd)for the first bedroom and 50 gpd for all subsequent bedrooms within the structure. Therefore,the projected flow volume for this project is: 2 Bedroom Primary SFR: 100+50= 150 gpd. (The property cannot support an ADU). CALCULATED NITRATE-NITROGEN LOADING FOR THE PROPOSED 2 BEDROOM SFR: HANTZSCHEIFINNEMORE EQUATION INW(1 -d)+RNb Nr= (I+R) Where: Nr = Resultant average concentration of nitrate-nitrogen in recharge water-(ppm NO3-N) I = Volume rate of wastewater entering the soil averaged over the APN Parcel area in inches per yr. Nw = Total nitrogen concentration of wastewater in mg N/L d = Fraction(%)of nitrate-nitrogen loss first in the septic tank and then due to denitrification in the soil environment. R = Average recharge rate of rainfall-inches per yr Nb = Background nitrate-nitrogen concentration of rainfall recharge, exclusive of wastewater influences. Values and Assumptions: I= 150 gpd x 365 d/y= 54,750 gals/v=7,320 cu ft = 8.8 in/yr 0.23 Ac x 43,560 sq ft/Ac x (1 ft/12 in) Nw= 35 mg N/L reduced 33%due to septic tank volume increase=23 mg N/L. d = Assume 35%based on soil laboratory test results. R = 8.82 in/yr per Hantzsche NRR. Nb= Assumed to be 0.1 ppm NO3-N. 8.8 in/yr x 23 mg N/L x 0-0.35)= 132+(8.82 in/yr x 0.1 mg/L)=7.5 ppm Nr= (8.8 in/yr+8.82 in/yr) Nr =7.5 ppm as nitrate-nitrogen(NO3 N) or 34 ppm as nitrate (NO,) ONSITE WASTEWATER TREATMENT SYSTEM DESIGN A Site Plan of the proposed SFR layout has not been completed since the owners wanted assurance the proposed development would be accepted by the applicable County Agencies, particularly EHD. At this time, the OWTS design is presented to demonstrate the maximum environmental protection, as detailed in this Report and Plans. Design details include: A P&L Concrete, Inc., 2,000 gallon septic tank must be installed. This tank should be traffic-rated since there is a'possibility of vehicular traffic over the tank due to the small Parcel area. Effluent from the septic tank will gravity to a three-hole D-Box,then gravity through two perforated, level leachline pipes with capped ends in the 40 ft E-W x 10 ft N-S, double-depth filter bed. The primary filter bed disposal area and the 100%reserve/replacement area must be installed in the northeast corner of the property. The existing domestic well must be destroyed and a new well drilled in the extreme northwest corner of the property. Page -4- Chesney Engineering, Inc.