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(§ 7.0) CONCLUSIONS The perc test results for proposed Parcel A and B show acceptable percolation for the management of any future septic system effluent flows at typical leachline depths. As noted from the perc test results, as the soil becomes increasingly saturated, the percolation rate potential decreases. Given that the perc tests were run for four hours, inducing maximum soil saturation, it is evident that the native on-site soils will manage any future effluent flows,provided the leachfield(s) are sized appropriately. EHD requires that there be sufficient distance for"treatment"of septic effluent before it encounters the groundwater table. This distance is normally regarded to be five feet for leachlines and 10 feet for sumps and seepage pits. Therefore, sufficient distance exists between the bottom of a maximum depth leachline trench at 42 inches and the current groundwater depth of--15 feet. (§ 6.8 Although there is no proposal to build on proposed Parcels A and B, a septic system for any future development will be dependent upon the number of bedrooms within a new structure, or the number of toilets. Leachline length in this locale is stipulated by EHD to be 100 feet for each bedroom. Determination of a bedroom is made by closets. If a room has a closet, it is designated as a bedroom. From the total lateral length of leachline, a filter bed area can also be calculated, if so desired. (§ 8.7) No problems are anticipated for any future septic system on the Parcels, other than typical lifespan concerns. An engineered septic system will not have to be installed for this project unless there are continual failures. The new system must have at least a 50% standby replacement area / incorporated into the design, which will be easily achieved due to the surrounding open areas. Any new septic system structures for the property must comply with the "distance" requirements from property borders, roads, irrigation ditches, etc. It is important to recognize that all septic systems have a lifespan, which is dependant on several factors and is therefore difficult to determine. Septic system leachline failure would primarily result from the advanced formation of a"biomat" or "clogging mat" on the wetted soil/effluent interface. This mat is composed mostly of aerobic and anaerobic bacteria and bacterial products consisting of a slime of polyuronides and polysaccharides. If the soil/effluent interface is well aerated, a variety of soil microfauna such as nematodes and protozoa may digest the clogging mat bacteria. Since the shallow subsurface soils on the property consist of fine sands and clays, anaerobic conditions may prevail over time which may slightly decrease the expectant life of a septic system,/ Lifespan will be dependant upon the efficiency of the septic system to manage typical effluent flows. In addition, soil moisture content of the subsurface soils will play an important role in septic system operational capacity. For example, if heavy rains are experienced in any given winter, subsurface soil moisture content will increase,thus decreasing permeability. In unsewered areas and/or areas that have been, or currently are under agricultural production, it is highly recommended that bottled water be used for drinking and cooking purposes. Page -4-