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Analysis of water drawn from the domestic well on Parcel I reveals a nitrate concentration of 12 ppm nitrate (NO3). The construction details of this well are unknown, although as referenced, it is 180 feet deep. Nitrate concentration in the domestic well serving Mr. Browns residence is 7 ppm. Construction details of this well are also unknown, but it is known to be 280 feet. The Maximum Contaminant Level (MCL) for NO3 in drinking water is 45 ppm. Therefore, the underlying deep aquifers have not been significantly affected by nitrate sources. Nitrate sources may include confined animal facilities, fertilizer applications, and/or surrounding septic systems. The pesticides DBCP and EDB were below detection limits (BDL) which is equivalent to non- detect(ND). [51 CONCLUSIONS The perc test results for Parcel 1 suggests there will be sufficient effluent percolation at the shallow leachline depth of 42 inches. The perc tests indicate that percolative capacity is relatively static with soil saturation, but is heavily influenced by head pressure. It is important to note that all septic systems have a lifespan. This lifespan is dependant on several factors and is therefore difficult to determine. However, from the number of repairs and additions, it is evident that septic systems have longevity within this area. Septic system 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 consist mostly of a sandier soil material, aerobic conditions will probably prevail over time which may delay leachline failure. Seepage pits and sumps are not permitted in this area due to the high water table. If a new septic system is ever installed on Parcel 1 or the Designated Remainder, the leachfield must be hydraulically protected during the rainy season to prevent inundation. A 50% standby replacement area must also be incorporated into the design of the septic system. All related septic system structures and a possible new domestic well must comply with the published "distance" requirements from property borders, roads, irrigation fields, etc. The nitrate concentrations determined in the underlying groundwater indicate there has been very low impact considered back round nitrate levels. Mr. Brown's well, which is 100 ft deeper than Mr. Kelley's well, illustrates a 42% decrease in nitrate concentration (12 ppm vs. 7 ppm). Regardless of the nitrate concentration of any well water in rural areas, it is recommended that bottled water should always be used for drinking and cooking purposes. 3 valley Ag Research