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r TABLE 2 PERCOLATION TEST RESULTS WITH CORRESPONDING APPLICATION RATES IN GALLONS / FT2 / DAY 36 INCH DEEP PERC TEST 5.6 min/inch / 0.800 gallons/ft2/day 96 INCH DEEP PERC TEST 62.5 min/inch / 0.190 gallons/1t2/day Application Rates adapted from Waste Quality Control for Siting, Design, Operation and Maintenance of On-site Wastewater Treatment Systems, based on the Perc Rate. D. GROUNDWATER INFORMATION NLS§ 2.1, SSS§ 4.1. Groundwater depths and elevations throughout San Joaquin County are illustrated on maps published by the County Flood Control and Water Conservation District. The 2016 Lines of Equal Depth Map indicates the depth to water at 28-29 ft. The Lines of Equal Elevation Maps groundwater directional flow is in a northeasterly direction. NLS§ 2.2, 3.1, SSS§ 2.1, 4.2. Properties to the north, south, and west are currently commercial, industrial and residential. Considering that this area was farmed for decades, along with onsite wastewater treatment systems density, there is a significant potential for nitrate contamination of the underlying groundwater. NLS§ 2.3, SSS§ 4.3, 4.4, 4.5, 4.6. There is no on-site well(s), nor has there apparently ever been a well on the portion of the property occupied by Robertson's. Although the water source is municipal, a water sample was obtained from the batch plant for analyses. The water contains <0.6 mg/L of nitrate and total alkalinity of 56 mg/L. Calculation on the Alkalinity Requirement for Nitrification The nitrate-nitrogen loading calculations are contingent upon the environmental factors required for nitrification to occur. These conditions include soil pore-space oxygen content, soil temperature, pH, electrical conductivity, organic matter, cation exchange capacity, and alkalinity. Alkalinity in wastewater effluent is derived from the water source, in addition to the introduction of wastes. Nitrification consumes approximately 7.1 mg of alkalinity for every mg of ammonia- nitrogen (NH4-N) oxidized. Nitrification of the average Total Nitrogen (TN) concentration of 62 mg/L, as determined below, would require: 62 mg/L NH4-N x 7.1 mg CaCO3 = 440 mg/L alkalinity. The alkalinity in the municipal water was determined to be 56 mg/L. Therefore, soil alkalinity, which is significant, and alkalinity from wastes must provide a sufficient alkalinity concentration for nitrification to occur. Page -4- Chesney Consulting