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Therefore, based upon the findings by researcher Bauman, et al, a value of 62 mg N/L in septic effluent will be used to calculate nitrate-nitrogen loading for this project(See Also Kaplan-Septic Systems Handbook,Pg. 147). B. CALCULATED NITRATE-NITROGEN LOADING NLS§3.4,3.5,3.6. The calculated nitrate-nitrogen impact to the soil and ultimately to the groundwater is difficult to determine due to the large number of variables involved and variables unknown at this time. These include: 1.) Nitrate impact from upgradient and onsite dairy nitrogen sources, 2.)Variability in wastewater flows, nitrogen concentrations and dilution effects from stormwater recharge, 3.)Changes in groundwater directional flow and elevation,4.)Denitrification potential within the soil environment and within the confined and/or unconfined aquifers. The Hantzsche/Finnemore Formula is used below to calculate the average resultant concentration of nitrate-nitrogen in effluent recharge water from the proposed on-site septic system serving the two restroom facilities and the sink in the break room. This concentration must not exceed 10 ppm nitrate-nitrogen(45 ppm as nitrate), otherwise mitigation factors must be implemented. The nitrate loading equation must incorporate the area that has been assessed on a gross developed area basis. The APN parcel is typically the area defined for loading assessment. However,the subject parcel is 100 acres in area,thus making the loading calculations inconsequential when comparing very small wastewater flow volumes to a very large area. Secondarily,the R&S Dairy is under the Dairy General Order promulgated by the Central Valley Regional Water Quality Control Board whereby the nitrogen generated by the dairy facility is closely monitored and accounted for. Consequently,the area for nitrate loading assessment will consist of the milkhouse and the area south of this building footprint which incorporates the primary disposal area and 100%replacement area: (65'+47)E-W x 350'N-S =39,299 sf(0.9 ac). Calculated nitrate-nitrogen loading from the developed area of the property: INWQ - 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 described area in inches per yr. Nw = Total nitrogen concentration of wastewater in mg N/L d = Fraction(%)of nitrate-nitrogen loss due to denitrification in the high clay content soil. R = Average recharge rate of rainfall- inches per yr. From Water Balance Analysis Nb = Background nitrate-nitrogen concentration of rainfall recharge, exclusive of wastewater influences (ppm NO3-N). 6 Chesney Consulting