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Soil Suitability/Nitrate Loading Study <br /> Proposed Global Carrier Inc. ■ Manteca, California 1rerracon <br /> August 8, 2018 v Terracon Project No. NA187034 <br /> 2.3.5 Nitrate Loading Scenario <br /> A nitrate loading scenario was performed to determine the impact from the proposed project. The <br /> scenario utilizes the variables discussed previously which represent the estimated conditions and <br /> uses associated with this project. The following table presents a summary of the nitrate loading <br /> calculation for the site. A copy of the nitrate loading calculation is included in Appendix G. <br /> Table 8. <br /> Summary of Nitrate Mass Balance Equation Proposed Development. <br /> Result Average Effluent Leach Field Deep <br /> Daily Concentration Percolation <br /> Parcel (Nc)* Acres(A) Effluent (Nw) Denitrification of Rainfall <br /> (mg/L-N) (Q)(9pd) (mg/L-N) (d) (R)(in) <br /> 1 5.9 10.0 156.8 85 15 2.86 <br /> `Maximum contaminant level(MCL)for nitrate in drinking water is 10 mg/L-N. <br /> 2.3.6 Impact of Nitrate Loading to Nearby Water Sources <br /> Since the subject property is relatively flat, we do not foresee percolating effluent affecting any <br /> surface water sources. <br /> 2.4 Discussion of Nitrate Loading Results <br /> 2.4.1 Total Nitrate Impact <br /> Based on the method and assumptions described, the result of the nitrate loading balance (5.9 <br /> mg/ L-N) indicates that the proposed development on the site should not cause a buildup of <br /> nitrates in the aquifer above 10 mg/L-N. <br /> For comparison, Terracon additionally calculated the nitrate mass balance for the existing <br /> residential land use based on an average daily flow of 280-gallons per day (2 bedrooms x 2 <br /> persons x 70-gallons per day)and effluent concentration of 35 mg/L-N. Based on the calculation, <br /> the nitrate mass balance is 4.3 mg/L-N for the existing residential septic system which is also <br /> below the MCL. The calculation for the residential use does not include the existing agricultural <br /> land use. <br /> 2.4.2 Methods of Mitigation <br /> Because of the favorable result of the nitrate loading calculation, no mitigation measures are <br /> warranted. <br /> Responsive■ Resourceful ■ Reliable 17 <br />