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TABLE 3 PRECIPT`%AND �'�`P� �T,T1Cf� ' MONTH/YEAR TOTAL PRECIPITATION (in) TOTAL Eto (in) POTENTIAL DEEP PERCOLATION (in) Feb 2014 2.67 1.91 0.76 + 4.87 = 5.63 Dec 2014 5.83 0.96 Nov 2015 1.95 1.89 0.06 + 0.90 = 0.96 Dec 2015 2.14 1.24 Jan 2016 4.38 1.11 3.27 + 0.85 = 4.12 Dec 2016 2.07 1.22 Jan 2017 5.50 1.09 4.41 AVERAGE 5.63+0.96+4.12+4.41=15.12=4= 3.78 3.78 III. NITRATE LOADING STUDY FINDINGS A. WASTEWATER CHARACTERISTICS AND FLOW VOLUME PROJECTIONS WASTEWATER CHARACTERISTICS The wastewater characteristics are anticipated to be those normally found in typical domestic or household systems. The scientific literature cites domestic wastewater nitrogen concentrations to be anywhere from 35 mg/L to 45 mg/L N, and up to 62 mg/L. An average concentration of 45 mg/L will be used in the calculations below and will be adjusted based on scientific data and the recommendation of installing a 2,000 gallon septic tank instead of the required 1,200 gallon tank for the three bedroom modular home. WASTEWATER FLOW VOLUME PROJECTIONS To determine nitrate -nitrogen loading from any project, wastewater flow volumes must be determined as accurately as possible. Domestic flow volume projections are typically approximated from the USEPA Onsite Wastewater Treatment Systems Manual, Pg. 3-4. However, for nitrate loading calculations, the EHD currently requires wastewater flow volume projections from single family residential structures to be calculated as follows: 100 gallons per day (gpd) for the first bedroom and 50 gpd for all subsequent bedrooms within the structure. Therefore, the projected flow volumes for this project are: 2 Bedroom existing single family residential structure: 100 + 50 = 150 gpd. 3 Bedroom existing mobile home structure: 100 + 50 + 50 = 200 gpd. 3 Bedroom proposed modular home structure: 100 + 50 + 50 = 200 gpd. Total Wastewater Flow Volume: 150 + 200 + 200 = 550 gpd. 5 Chesney Consulting