SR0085800_SSNL - Laserfiche WebLink

Home Browse Search

12958/12970 E Jahant Road Project No. 2022-00037 Pa g e 18 nitrogen above 10 mg/L over the long term. Based on the relatively flat topography of the site, we do not foresee percolating effluent affecting any surface water resources. 6.0 DISCUSSION OF NITRATE LOADING RESULTS 6.1 Total Nitrate Impact Based on the methods and assumptions described, in addition to our professional judgement and geologic setting, we believe the proposed project is unlikely to cause a build-up of nitrate in the ground water above background concentration level of total nitrogen 10 mg/L over the long term. 6.2 Nitrate Loading - Methods of Mitigation Based on the mass balance analysis results, in addition to our professional judgement, low septic tank density, and geologic setting showing the deep groundwater table underlying the Site, we believe the proposed project will not likely cause a build-up of nitrate in the ground water above the background concentration of total nitrogen above 10 mg/L over the long term. It is our professional opinion that mitigation measures are not warranted at this time. However, it should be noted that mitigation measures may be recommended and required at a later date based on changes in nitrate in the groundwater, and long-term monitoring results for the region. 7.0 EXISTING AND PROPOSED SEPTIC TANK USAGE 7.1 Existing On -Site Septic Tank Usage, Permits and Repair History There are three existing septic systems located on site. Based on EHD data, a 1600 gallon concrete septic tank was installed for a 3 -bedroom residence in 1997 (Permit No,: SR0013806) with leach lines and seepage pits to 25 feet below ground surface, Permit SR0034121 indicates a 1600 gallon concrete septic tank was installed in 2003 to accommodate a three-bedroom residence with leach lines and seepage pits to 25 feet bgs. One repair permit (SR0078201) dated September 16, 2017 is on record indicating additional leach lines and seepage pits were installed due to "low infiltration" issues. No record was observed for the existing septic system that serves the two-bedroom, one -bath home on site. Permits are available for review in Appendix C. 7.2 Expected Maximum Septic Tank Usage for Site Expected maximum septic tank usage for the Site is to accommodate the existing three residential houses and the proposed three-bedroom, two -bath, single-family residence. Table 2 discusses the typical quantity of effluent for the expected septic tank usage would be a total average of 750 gallons per day. Petralogix Engineering, Inc 26675 Bruella Road, Galt, Ca 95632 (209)-400-5729 www.petralogix.com