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IV. CONCLUSIONS AND RECOMMENDATIONS SSS§ 5.4,6.8. The soils underlying the subject property show acceptable permeability at the shallow depths representative of filter beds and leachline depths. Acceptable permeability also exists at depths representative of sumps. However,due to area constraints and nitrate loading mitigation,a filter bed is proposed for effluent disposal and not leachlines and sumps. It can be anticipated that for long-term effluent acceptance rates, the permeability of the soils will no doubt slow due to biomat formation. The perc rates were acceptable because they were not too rapid. EHD typically defines excessive percolation as less than 5 minutes per inch. If excessive permeability was encountered,groundwater protection methods such as importing a soil liner of finer grain size(silts and clays)under the effluent disposal area would be required. From the soil chemistry test results, it appears that there is some denitrification potential from the soils,but not as significant as has been observed in other locations of San Joaquin County. The soil analytical test results show low concentrations of subsurface soil nitrate-nitrogen,even though the subject property has been under agricultural production for at least the past four decades. The amount of nitrogen applications in the past are of course,unknown. However, it is obvious the farmer of the almonds currently on the subject property is applying nitrogen carefully and accurately. Jensen and Siegrist(1990)found the factors that favor denitrification are fine-grained soils such as clays and silts layered with soils consisting of alternating fine-grained and coarser grained soils with distinct boundaries between the texturally different strata. Percolating water encountering coarser soil strata will accumulate on top of this stratum until sufficient soil moisture builds up for the soil water to travel into this stratum. As referenced, the encountered hardpan strata may be promoting denitrification through this phenomena. NLS§4.1,4.2, SSS§ 6.7. The nitrate loading calculations show that even with an extremely high Average Daily Flow effluent volume, the nitrate loading potential for the subject property and the proposed facility is under one-half of the Maximum Contaminant Level for nitrate-nitrogen. �,- Another source of nitrate loading can be from on-site lawns and landscaping , which is estimated to be 24% and could be significantly higher. It is recommended to use"slow release"nitrogen fertilizers on the lawns and landscaping to reduce nitrate loading from these areas. If nitrogen fertilizers are used,they should be applied under the package guidelines. 11