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F75.0 Filter Bed: Sch. 40 PVC 0.75'nominal diameter, 1/8" orifice directed at 12 o'clock 5.0 ft long. "Tum-ups"at the ends of each lateral for clean-out contained within valve cover boxes. e Rate: 1/8" with 5 ft residual head=0.43 gpm orifices/lateral x 0.43 gpm/orifice=2.67 gpm/lateral Network Discharee Rate (NDR) For Each Filter Bed = 16 laterals x 2.67 gpm/lateral =42.7 gpm Manifold for Each Filter Bed=2" Sch. 40 PVC Total Dose Volume (TDV) From Each Pump: 0.028 gals/ft x 31.3 ft x 16 laterals= 14 gals x 5 times lateral void volume=70 gals 2"x 53.8 ft manifold=0.174 gals/ft x 53.8 ft=9.4 gals Transport line=2" =0.163 gals/ft x -100 ft= 16 gals 70 +9.4+ 16=96 gals/dose-42.7 gpm=2.3 min/dose 2,180 gpd ADF=96 gals/dose=22.7 doses/24 hr period/each pump Infiltrator Specifications: See Appendix F. Standard Infiltrator Chamber SC(Shallow Cover). Use shallow cover due to water table and mounding concerns. Due to clayey/silty soil structure at soil-effluent interface, a 2.5 inch layer of clan washed sand must be laid down over a scarified soil surface before installation of chambers. This will prevent"silt-over"of the interface that may be caused by a portion of the pressurized effluent splashing down onto the native soil surface. Silt-over would cause a significant reduction in infiltration and percolation. Volume of sand required: 3,368 sq. ft of filter bed x (2.5 inches x(1=12))=700 ft',or 26 yds' Monitoring of Each Filter Bed: Monitoring of effluent with four monitoring ports or wells within,or on the perimeter of each filter bed area. Observation tubes: 4" PVC Tee at soil/effluent interface with 4" riser extending above the soil/grass surface by at least 0.5 foot,with a screw type cap (EHD Requirement). See Appendix F for schematic. IV. CONCLUSIONS AND RECOMMENDATIONS SSS§ 5.4 The surface soils underlying the proposed filter bed disposal area to approximate) four feet in depth consists of a comparatively high clay content soil with a surprising degree of permeability, as evidenced by the percolation test results. At five feet in depth, a high density clay stratum was encountered in the future filter bed test boring. Two additional borings conducted to the south of the proposed disposal area in conjunction with the other test borings conducted in the two other referenced locations, reveal that this clay stratum at the 5 and 10 ft depths may be localized and not pervasive throughout the filter bed. From the soil chemistry results, it appears that denitrification (from 5 ppm to 1 ppm NO,-N- 80% reduction)has occurred from the surface soils down to this 5 ft clay stratum.. It is theorized that the soil environment above this encountered clay stratum may become anaerobic due to high moisture content as percolating water encounters this slower permeable stratum. This is beneficial for reductions in nitrate concentrations. 17 Chesney Consulting