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September 20,2002 <br /> Job Number: LG02-261 <br /> Page 10 <br /> The vineyard and orchard management of the property with respect to the application of <br /> soil fertilizers and irrigation is conducted by Ben Goudie of San Joaquin Sulfer. Mr. Goudie <br /> described the typical fertilizer and irrigation practice for the property. Mr. Goudie said that <br /> normally, about 23 units of nitrogen per acre in a solid form are shanked into the ground at a <br /> depth of 6 inches. One unit of nitrogen is equivalent to one pound of nitrogen. In addition, <br /> fertilizers are often broadcast to the cover grass as needed. He indicated that petiole and soil <br /> samples are tested annually for nitrates and other nutrients. Irrigation was applied as needed. <br /> -- Since the vineyard system is periodically tested and recommendations are provided by <br /> agricultural consultants, the vineyard is assumed to be "in balance"—the proper nutrients and <br /> irrigation is applied to the vineyard. The irrigation and nitrogen provided to the vineyard will <br /> not be considered in the nitrate loading balance. <br /> Nitrate Loading Analysis <br /> The nitrate loading analysis was performed for two (2) different scenarios; a 2 acre <br /> parcel with a residence and SDU and a 45.63 acre parcel with a residence and SDU. The <br /> analysis indicated that the Nc value may exceed 10 mg/L-N when a second dwelling unit is <br /> installed on the property. The water quality goal of less than 10 mg/L (Nc) is recommended for <br /> the percolating effluent on each parcel. The added load of second dwelling unit in addition to a <br /> 3 bedroom residence may cause a negative impact to ground water. A summary of the nitrate <br /> loading analysis is presented next. <br /> Table 6. <br /> Summary of Nitrate Mass Balance Analysis. <br /> Result(mg/L-N)Nc* Acres Quantity Effluent Denitrification Rainfall <br /> (gal/day) Concentration (%) Infiltration <br /> (mg/L-N)* (in) <br /> 13.9,(Plate 9) 2 525 45 10 6.84 <br /> 1.06, (Plate 10) 45.63 525 45 10 6.84 <br /> *Note: Maximum contaminate level(MCL)for Nitrate is 10 mg/L-N and 45 mg/L as NO,. Please note that the <br /> average septic waste water level of 45 mg/L-N is not related to the nitrate drinking water MCL of 45 mg/L as NO,. <br /> .— SDU is Second Dwelling unit containing up to 2 bedrooms. <br /> roc�so <br /> r 4 <br /> > .n <br /> Z r <br /> O � <br /> �JSpG♦ <br /> r <br />