SU0002196 SSNL - Laserfiche WebLink

Home Browse Search

R_ June 21, 2000 Job Number: LG00-173 Page 13 The sum of all nitrogen sources and water quantities for an average year were identified and tabulated. The sources were set to the average daily rate in units of milligrams nitrate as N and liters. The result of the nitrate loading analysis indicates that viewing the septic, winery wash waste, and rain fall for the 20 acre site for an average year, the average concentration is estimated to be 0.18 mg/1-N, about 2% of the maximum contaminate level for the drinking water standard of 10 mg/1-N. See Table 6 for mass balance calculation. VIII. CONCLUSIONS AND RECOMMENDATIONS In conclusion,the percolation test indicated the onsite soils percolate 4.4 minim at a depth of 3.0 feet. The interviews with local neighbors indicated that both standard leach field systems and leach field systems with seepage pits exist near the site. The 10 foot exploratory boring encountered no shallow groundwater was encountered. The depth to ground water in the area was between 39 and 42 feet in 1998. The concentration of nitrate from the proposed septic tank, wine barrel wash, and rain water was estimated to be 0.18 mg/1-N. The estimated average nitrate level of the percolate from the sources is well below the maximum contaminate level (about 21/o of maximum) for the drinking water of 10 mg/L. To assure the best performance from the new septic system, our recommendations for the project are as follows: 1) To ensure maximum denitrification of the septic system eluent, the leach line trenches should be supplemented with an organic carbon source such as ordinary gardening peat soil supplement. An appropriate amount of peat soil could be .. purchased from a gardening store and placed in the leach line trenches to form a biomat filter. Charcoal is not recommended for an organic carbon source. 2) If any large gathering or event is planned for the winery that may exceed the septic usage estimate,the use of portable chemical toilets for those events or periods is recommended. 3) The design of the septic system should follow the San Joaquin County"Sewage Standards" criteria. 4) The winery wash water should be analyzed at a convenient time to determine the nitrate concentration and confirm the level is below drinking water standards. If the nitrate concentration exceeds the drinking water standard, our office and San 'pER j04