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I-The primary constituent of concern for the EHD after the introduction of wastewater to the soil environment is nitrate-nitrogen. The behavior of nitrogen in the vadose and plreatic zones of the soil environment are extremely complex, variable and very difficult to predict. On a mass balance basis, the three species of nitrogen (NO3-N, NH4-N and Org-N) demonstrate decreasing concentrations with increasing depth in the soil tested from under the leachline. For example, NO3-N concentrations decreased 80%, from 5 ppm at the 5' depth to 1 ppm at the 14' depth under the leachline. This decrease may be primarily attributable to denitrification. The TKN concentration decreased 62%, from 232 ppm at the 5' depth to 88 ppm at the 14' depth under the leachline. The virgin soil indicated variability in nitrogen concentrations with increasing depth, specifically NI-14-N and Org-N. There was a decrease in NH4-N and an increase in Org-N concentrations at the 9' depth, in comparison to the 5' depth. At the 14' depth, the NH4-N increased, but the Org-N was below detectable levels (BDL). The virgin soils also demonstrate similar denitrification potential as the soil under the leachline. The NO3-N concentration at the 5' depth was actually 1 ppm higher than under the leachline at 6 ppm, and decreased to 2 ppm at the 14' depth; a 67% decrease in NO3-N concentration. As referenced, the subsurface soils are extremely tight and compact, and become more so with increasing depth. Reviewing the magnesium percentage of the Cation Saturation, a very high percentage and concentration of magnesium is noted. This high magnesium percentage is binding the high sand percentages and creating this tight soil. And although there is comparatively low clay content in the soils creating a Sandy Loam soil throughout the profile, this high mag content is most likely causing greater anaerobic environments with increasing depth, thus promoting denitrification of nitrate produced from nitrified ammonium. The TKN concentration decrease may be attributable to Org-N ammonification and microbial assimilation of NH4-N. The results of the soil testing below in Table 2, compare soil samples from under the leachline (LL) and under virgin soil (VS), for each sampled depth (5', 9' and 14'). Page -4- Chesney Consulting