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[6] CONCLUSIONS The traditional perc rate, the trench pump-in test result and the permeability test result on the soil from the 14 ft depth demonstrate that sumps or seepage pits must be used for the proposed septic system serving the new milk parlor. Additionally,the information obtained from the Environmental Health Department regarding the number of Application permits for seepage pits also indicates a need for this type of septic structure. The traditional perc test shows the water infiltrating and percolating initially at a slow rate and then increasing three-fold as the soil-water interface becomes wet. Since water has a great affinity for itself,percolation is promoted as the soil reaches field capacity. The final perc rate taken between 1115 and 1140 (25 min) exhibits a perc rate of 2.5 min/in. Trench pump-in test calculations demonstrate an acceptance rate (AR) in gals/sqft/day, as follows: 1. Length of trench= 12 ft 2. Width of trench= 1.5 ft 3. Depth of trench= 15 ft 4. Depth of water mantained in bottom of trench= 1.5 ft 5. Depth below bottom of trench at periphery of plume = 3 ft 6. Total water applied during test= 85 X 5 =425 gals 7. Extent of water plume area: water surface = 1.5 ft X 4.5 ft :. plume area is estimated to be: 7.5 ft X 10.5 ft= 78.8 sq ft. _ 8. Acceptance Rate (AR) =total flow absorbed= (area)(time) 9. AR=425 - (78.8)(3 hrs-24 hrs/day)=43.2 gals/sq ft/d The permeability test was conducted under ASTM D2434-84 with a constant-head permeameter. Test results found in the Appendix illustrate the sand strata at 14 ft to possess a coefficient of permeability of 0.0172 cm/s (49 ft/day). All three test results indicate excellent percolation within the referenced sand strata. The following calculations show leachline and pit/sump requirements: 1200 Base Tank Capacity (BTC) + 15 gal/person/shift X 2 shifts X 6 people = 180 average daily flow(ADF) = 1380 Calculated Tank Capacity (CTC) 1380 X 0.250=345 lineal feet of leachline. Therefore: two-one hundred foot leachlines may be used in conjunction with two 33 in. dia. X 18 ft. deep pits at the ends of each leachline: 200 lineal ft+ 2 X 60 ft leachline equivalent for two pits= 320 ft of leachline. If approved by the Environmental Health Department, sumps may be used instead of seepage pits. It is imperative that whichever structure is used, either the driller or the backhoe operator drill or excavate down into the referenced sand strata and continue through the strata. With an extend-a-hoe, this should be 18 ft below grade. With a drill rig,the boring should extend to at least 18 feet. It can be assumed that only a small percentage of the total effluent volume will percolate through the leachlines due to the clay soil at leachline depth. To facilitate leachfield percolation, the referenced hardpan layer should be breached during leachline emplacement. 3 Vaffey Ag JIVasearch