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SEPTIC TANK CAPACITY EXAMPLE: Recomended tank capacity for a pump out interval of three yrs: 2.8(QAVE)x Peaking Factor(PF) =2.8(18 people x 15 gals/day=270 gals/day)x 1.5 = 1,134 gal tank capacity required: Use one- dual compartment 1,600 gallon tank with effluent filter, or two - 1,200 gallon tanks in series, with effluent filter. DETENTION TIME EXAMPLE: Detention Time= 1,600 gal tank capacity x 0.70 (30%volume lost to sludge/scum accumulation) 1.5 (Peaking factor)x 270 gals/day Detention Time=2.8 days. The minimum acceptable detention time is 1.0 day. LEACHFIELDS/FILTER BEDS LEACHFIELD/FILTER BED EXAMPLE: 1,600 gallon septic tank. Therefore,the Base Tank Capacity= 1,600 gal: Base Tank Capacity(BTC) +Average Daily Flow(ADF)x Soil Factor(SF) _ 1,600 gal BTC+(18 people x 15 gallons=270 ADF)= 1,870 x 0.225 SF=421 lineal ft of leachline FILTER BED=421 LFLL x 4= 1,683 sq ft or 41 feet square. IV. CONCLUSIONS The nitrate loading calculations illustrate that the anticipated number of people on the property will contribute approximately half the MCL for nitrate from the effluent recharge. Consequently, the loading calculations show the property can actually support twice the number of people anticipated, and not exceed the MCL for nitrate in drinking water. The characteristics of the soil reveal structural differences between the two soil types present on the property. More importantly however, is the high probability that subsurface soil compaction, caused by the tandem axles and wheels of semi trucks,has created a soil environment virtually absent of permeability. This is the reason that the EHD does not allow parking or driving over leachfield areas. Careful consideration must be given to any future septic system installations on the property, in areas where there have been truck parking and driving. This would include "over- excavating" leachline trenches several feet in an attempt to undercut soil compaction. Applications for repairs and additions on file with EHD reveal that the soils in the locale of the property to Ionia-term efauept management. This was indicated by the number of permit applications and the near y Arbor Mobile Home Park, which has had severe effluent management problems. 12 Chesney Consulting