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(§ 4.3„-4.4;4.5,4 As noted,t is no on-site well on the pr erty. It is against EHD policy to sm le wells not associat with the subject property for ting purposes. (#'4.2) Considering the area has been intensely farmed for the past several decades, it may be possible for there to be elevated nitrate concentrations in the underlying drinking water aquifers. Before drilling any new well,the landowner should consult with EHD and private well drillers as to depth, quality and quantity of domestic water in this locale. (§ 7.0) CONCLUSIONS The perc test results for proposed Parcel 1 and 2 show acceptable percolation for the management of 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 only slightly 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. As referenced, since the property is zoned R-R, a double leachline system with an alternating distribution box must be installed, in accordance with EHD requirements. 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 of 42 inches and the current groundwater depth of-50 feet. This groundwater depth is unusually deep in comparison to historical measurements, and may be attributed to the severe drought. JF&8) Septic systems for any future development will be primarily 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. M . No problems are anticipated for any future septic system on the Parcels, other than typical i espan 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 space. Any new septic system structures for the property must comply with the "distance" requirements from property borders, roads, utility easements, 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. Page -4-