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"woe November 18, 1999 Job Number: S99307 Page 9 The estimated total average yearly nitrate loading concentration for the property is estimated to be 5.78 mg/1-N, about 58% of the maximum contaminate level for the drinking water. It is anticipated that a portion of the effluent may evaporate, be consumed by surface plants, while a portion may evidentially reach ground water if no confining clay zones are present below the site. It is unknown if this will occur. If this does occur, the concentration of the percolate has been calculated to be well below the drinking water standard and will lower(by dilution)the elevated nitrate levels of groundwater. This process could be viewed as beneficial to overall ground water quality. The source of the elevated ground-water nitrate is unknown but may originate from septic uses or agriculture located to the west. The ground-water gradient in this area was found to flow east to northeast in the past years. Since there is a reasonable possibility that improperly constructed septic systems located to the west may be contributing to the elevated nitrate concentrations of ground water, it is important that any new systems in this area are designed and constructed properly. Our recommendations for the project are as follows: 1) If the site has sufficient area, the use of seepage pits should be avoided if possible. We realize that space may be a limiting factor and the use of seepage pits may be needed. If they are needed, shallow pits are preferable to deeper pits and they should be placed at the ends of leach lines. The leach lines should be placed no deeper then 36 inches, less is preferable. 2) The leach line trenches should be supplemented with an organic carbon source such as a organic silt, organic clay, or an ordinary gardening peat supplement. An appropriate amount of peat soil supplement could be purchased from a gardening store for example, and lined in the trenches to form a biomat filter. This will promote denitrification of the effluent. Charcoal is not recommended for an organic carbon source. 3) Bottled or imported drinking water should be available for use by the staff and customers of the business. The drinking of the well water should be avoided due to the nitrate water test exceeding the maximum drinking water standard. The water well could be used for irrigation and other non-consumable purposes. SSS OCA