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100%Reserve Replacement Area: The 100%replacement area can be accommodated to the northwest of the primary leachfield area: 4-48 inch diameter seepage pits=4 x 90 ft of leachline equivalent=360 ft r 5 -50 ft sections of leachline=250 ft 1 -60 ft section of leachline=60 ft 360 ft+250 ft+60=670 equivalent lineal feet of leachline for..100% Replacement Area.. IV. CONCLUSIONS AND RECOMMENDATIONS SSS§5.4, 6.8. The soils underlying the subject propertyshow unacceptable-permeability at the shallow ti t depths representative of leachiines. Acceptable permeability exists at depths representative of sumps and i - seepage pits. It can be anticipated that for long-term effluent acceptance rates,the permeability.of these deeper soils will no doubt slow based on the factors described in this report. This includes historical evidence based on repairs/replacements/additions-permits within the study area along the Highway 99 corridor. The soil analytical test results show low concentrations of subsurface soil nitrate-nitrogen, even though (2. the subject property was under agricultural production for at least the past four decades. Also from the k soil chemistry test results, it appears there is significant denitrification potential within the property soils. The amount of nitrogen applications in the past'are-unknown, although decomposing organic matter from . residual crop decomposition may supply subsurface nitrate-nitrogen. Jenssen 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. .This was observed in the exploratory boring and may also explain the low soil nitrate-nitrogen concentrations,`and low concentrations throughout the Morada area. .Percolating water encountering coarser soil strata will accumulate on top of this stratum until sufficient soil moisture builds up for the soil water.to'tmvel into this.stratum.- NLS§4.2, SSS§ 6.7. Due to the referenced problems that Have occurred along.Highway 99 with -conventional septic systems, it is the opinion of EHD'thaf the upcoming new_General Plan may require 11 commercial facilities along Highway.99 which must operate with decentralized systems, to treat their. F wastewater to a higher degree. NLS§ 4.1. The nitrate loading calculations show the resultant effluent from the proposed project will have a nitrate-nitrogen concentration under the Maximum Contaminant Level.= A new well must be drilled for this project. Water frorti-this well must meet all the County;=State and Federal requirements. It is recommended that.the.well water be tested for the applicable constituents before final well completion. -- Domestic water use for this project, and landscape°water use within the leachfield area, must-be kept C �) to an absolute minimum because of the slow permeability soil stricture.at:leachline depth. This can be accomplished with low flow toilets and spring-loaded fixtures in the sinks. _ .# .. 10 Chesney.Consulting