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KLEINFELDER water per day, respectively. Based upon the staffing level provided and water usage per person, we estimate the winery expansion will produce 6,750 gallons of waste water per week. The Hanzsche equation was intended for residential developments and requires a value "A' for number of dwelling units per acre on septic tanks. Since this will be a commercial development, the "A" value was determined using an equivalent of homes, determined by dividing the estimated daily waste produced by 150 gallons per day (typical for residential 3 bedroom 2 bath homes). The selection of other parameters were based on previous studies by our firm, as well as a report dated March 19, 1997 by Questa Engineering Corporation and authored by Mr. Norm Hantzsche. The values presented below have been adjusted to account for the more sandy soils at the site. The equation is as follows: N,=AWNw(1-D)+ r AW+r Where: N, = Average calculated nitrate in groundwater resulting from domestic sources and precipitation —mg/l,as N A = Number of dwelling units per acres on septic tanks(unittacre)=0.29 as discussed above W = Annual wastewater loading per dwelling unit per acre(inches)=0.42 inches Nw = Nitrate concentration of nitrified leachfield effluent (mg/1) = 45 mg/1 typical (Hantzsche and Finnemore(1992)) D = Percent dentrification of leachfield effluent=0.35 percent R = Annual deep percolation of precipitation (inches) = 8.0 inches (Since the near surface soils consist of sands, conservatively equals '/2 the annual rainfall in the Lodi area) Nb = Background nitrate concentration of the deep percolating precipitation—mRA =2.2 mza as N Our calculations are as follows: Nitrate Loading NC = 0.29 (0.42) (45) (1 —0.35) +2.2 (8) = 3.56 + 17.6 = 2.61 mg/1 as N 0.29(0.42) +8 0.12 +8 In summary, the Hantzsche equation indicates that effluent generated by the proposed winery expansion will not raise the nitrate level in groundwater above state standards. Based on our percolation test result, a conventional septic tank and leach trench field should be suitable for disposal of waste water. One of the factors required by the SJCPHS is to determine the existing value of nitrate in the groundwater below the site. This service was not authorized and thus not performed by Kleinfelder. Bear Creek Winery currently maintains monitoring wells on-site and tests water samples for nitrates on a regular basis. We understand that the average nitrate level at an on-site domestic water well is 5.7 mg/L. We also understand the results of these tests will be provided to SJCPHS. 20-4599-O1.G01/201IR1454 November 21,2001 0 2001 Kleinfelder,Inc. Page 3 of 4