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l .If the entire chambered filter°bed area(8;833 ft') is considered, which-is plausible.because of louvers that are.built into the sides-of.the chambers, we find a manageable effluent volume under an LTAR of: 0.200 gals/ft2lday x 8;833 ft' = 1,767 galsiday. Because the soil nitrate-nitrogen concentration throughout.the soil profile is comparatively low, this will attenuate the amount of nitrogen migrating downward with the-percolating effluent. Some effluent will nitrify in the sand bed due to large porosity of the sand particles allowing oxygen intrusion. As the effluent enters the native'soil, the denitrification.potentialof the soil should denitrify an indeterminable percentage of nitrate. +' NLS§ 4.2, SSS§ 6.7. The design of the chambered filter bed to be placed high in elevation will take ' advantage of the indigenous soils that:possess favorable'qualities to inhibit nitrification, most notably tight soils with medium clay content percentages, iii addition to promoting denitrification. These tight,hardpan-type soils,as well as other soil types, can produce a rare.phenomenon referenced in the scientific literature in which the soil undergoes "heaving" and can replace the void space with-in the chambers with expanded soil. There is no test method to investigate for this phenomena and it was not witnessed in the two feet deep backhoe trench test. NLS§ 4.1. The nitrate loading potential-calculaten, n Page 17 reveals the,percolating effluent may have a resultant nitrate concentrate of 13.9 ppm, ich-is below the drinking water Maximum Contaminant Level (MCIO�of 45 ppm. _ e With regard to the calculated nitrat - it loading to the underlying.groundwater.table, it is "important to recognize that when adding one concentration of a solute(e.g., NO3-N concentration determined in the effluent recharge) to another concentration of a solute (e.&,NO3-N concentration determined in groundwater table), where both solutes are in ppm; the result is not cumulative or the sum of the two solutes. Parts per million is a mass ratio(mg per106 rng). For example, the Nr(the resultant average concentration of nitrate-nitrogen.in effluent recharge'in ppm-of NO3-N), was determined to be 3.1 ppm by the Hantzsche-Finnemore Equation, .This equals 3.1 milligrams of nitrate in 106 milligrams of water (one liter). If this 3.1 pprn concentration is added to the same volume of water-(1 x 106 milligrams) of the concentration determined in the water table underlying the proposed west disposal area, which was 20.2 ppm NO3-N{90 ppm NO3),then the resultant concentration is now: 3.1 milligrams per liter+ 20.2 milligrams per liter=23.3 milligrams in 2 x 106 milligrams (2 liters, or parts per 2 million) of water.. Therefore,to convert back to.ppm, the numerator and denominator must be divided by 2 with the result of 11.6 milligrams NO3-N per 1 x 106 milligrams, or 51.8 ppm nitrate -NO3. Therefore, the mixing layer located at the top of the first aquifer consisting of recharge effluent and existing phreatic groundwater theoretically will undergo a ilution effect from the percolating effluent. It is recommended that a flowmeter be placed on the transport line from the lift station by the office trailers. Consequently, only one meter,will,be needed, instead of installing two flowmeters - one on each pump discharge line-before the effluent is dispersed throughout the chambered filter bed system. 21 Chesney Consulting