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rV. CONCLUSIONS AND RECOMMENDATIONS he soil physical characteristics under the proposed wastewater disposal area reveal permeable soils i�n the upper and in the lower horizons. The upper soils within the profile contain a higher-than- expected clay content of 10%. This should be a sufficient clay content to impede saturated flow conditions of percolating effluent and provide biological wastewater treatment. The wastewater disposal system has been designed based on comparable wastewater flow volume data from a similar facility, correlated with the soil test results. The infiltration rate of 8.5 minutes per inch obtained from the Double Ring Infiltrometer test is equivalent to an effluent acceptance rate of 0.857 gals/ftz/day, as published in various scientific literature (e.g., California SWRCB Guidelines for the Design. Installation and Operation of Mound Sewage Disposal Systems.) Since the project will be on a flowmeter, average wastewater flow volumes can be easily calculated on a daily, weekly or monthly basis. Time intervals will be stipulated by EHD. As referenced above, the maximum daily flow of 1,000 gpd has been used for mounding analysis, nitrate loading calculations and filter bed sizing. If it is determined in the future that the average daily,/low exceeds this figure, there is more than ample area to enlarge the filter bed, along with additional replacement area. These areas are shown on the portion of the Site Plan illustrating the filter bed orientation. Certain appurtenances change the characteristics of the wastewater effluent such as filters within the septic tank and kitchen food-waste grinders. An effluent filter must be installed. If there is to be a kitchen or food processing facility within any of the proposed buildings, disposals or food waste grinders should not be used. It is imperative that no chemicals, solvents or petroleum products, other than very low concentrations of household cleaners be introduced into the septic system. Additionally, if there is to be any food production,preparation or processing facility in any of the buildings anytime in the future, a grease trap (interceptor tank) may have to be installed before this waste stream enters the septic tanks. It is important to recognize that all wastewater disposal systems and disposal areas have a lifespan. This lifespan is unpredictable due to the numerous operational and environmental factors involved. Clean-outs have been specified at the distal ends of the laterals. By using a long "bottle-brush" arrangement, the interiors of the laterals can be cleaned of biological slime build-up. Biomat buildup that will occur within the gravel bed and particularly at the soil/effluent interface is a naturally occurring process that is typically managed by allowing the filter bed to rest and rehabilitate naturally. Biomat decomposition may be accelerated by pumping air into the disposal system piping of a resting filter bed. It is conservatively estimated that the landscape grass cover over the filter bed area will take up approximately 30% of the effluent and consequently 30%the nitrogen from the Business Park project. Using an average daily flow estimate of 1,000 gpd and a nitrogen concentration of 88 mg N/L (See Page 8), we have the following landscape grass water needs and nitrogen concentrations theoretically absorbed by the grass, after the Business Park is completely built-out: The following Worksheet is found in A Guide to Estimating Irrigation Water Needs of Landscape Page -11- Chesney Consuhing