SU0006091 SSNL - Laserfiche WebLink

Home Browse Search

n March 28, 2007 NOA Project Number: E06122A 4.0 DISCUSSION OF NITRATE LOADING RESULTS j4.1 Total Nitrate Impact Based on the method and assumptions described the result of the nitrate loading balance indicates p g that the proposed development on the proposed site could cause a build up of nitrates in the aquifer FjJ above 10 mg/L-N.Where percolating effluent leaches into the ground,ground water quality may be impacted to some degree should the effluent reach ground water. �{ Fine-grained sediment and the degree of cementation on site can provide an added protection k between percolating effluent at the surface and ground water aquifers. The longer the effluent I € remains near the surface, the more treatment is enhanced due to natural processes within the soil. J ! Ground water is approximately 60 to 70 feet below ground surface on the subject property. The soils on the site were clayey loams; soils of this type do not typically present a high risk of excessive Fmass transport of nitrate or other constituents of concern. 4.2 Methods of Mitigation An engineered treatment system is recommended to reduce high nitrate concentrations. A treatment system can reduce nitrogen concentrations w) between 40 to 65 percent depending on water y g � p (zz/20 quality and influent makeup.Advanced treatment could bring nitrate levels close to the required l maximum contaminant level of 10 mg/L-N e 5.0 CONCLUSIONS AND RECOMMENDATIONS k Our office concludes that the Site is suitable for development with the use of an engineered treatment system. All septic system construction should follow the San Joaquin County On-Site Wastewater Disposal Standards where applicable. -p pp 5.1 Signatures A The signatures of the environmental professionals involved in the preparation of this report can be found on the cover sheet at the front of this package. 5.2 Attachments All required attachments and appendices can be found at the rear of this package. y 7 '00041 �1 {