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.J (§ 7.0) CONCLUSIONS FF7 test results for proposed Parcel 1 and Parcel 2 show acceptable percolation for the ment of any future typical septic system effluent flows at leachline depths of 42 inches. As m the perc test results, as the soil becomes increasingly saturated, the percolation rate potential decreases. As noted, deep percolation tests (Approx. 10-25 feet deep)representative of sumps or seepage pits were not conducted because of the favorable (in terms of permeability) surface soils encountered, representative of leachlines. However, it will be a requirement by EHD that any proposal to install aseptic system on this property will require seepage pits. This requirement must be conveyed to a potential buyer of the subject property. In addition, it must be conveyed to a buyer the possibility that additional percolation testing may have to be conducted if there is a proposal to install a leachfield outside of the 100 foot radius of the percolation tests conducted. 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. Therefore, sufficient distance exists between the bottom of a 25 feet deep seepage pit and the current groundwater depth of 105 feet. (§ 6.8) Any septic system for a future development will be dependent upon the number of bedrooms within a new house. Determination of a bedroom is made by closets. If a room has a closet, it is designated as a bedroom. (§ 6.7) 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, and irrigation ditches, etc. Inundation from irrigation water may be a concern. 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 clayey, sandy silt soils, anaerobic conditions may prevail over time which may decrease the expectant life of any new septic system. Lifespan will be dependant upon the efficiency of the septic system to manage typical effluent flows. Page -5- Chesney Consulting