SU0009927 SSNL - Laserfiche WebLink

Home Browse Search

C. SEPTIC SYSTEM DESIGN, OPERATIONAL PARAMETERS AND COMPONENTS �f5 SSS§3.7. Discussion of efficient operation, disposal field longevity, and environmental protection are based upon the environmental parameters discussed in this report. An overview of the system operation is as follows: Influent waste from the employee restroom, washer machine, sink/ dishwasher and kennel wash-downs will gravity flow into a new 2,000 gallon, two compartment septic tank. A Polylok PL-122 Effluent Filter must be installed at the outlet of the septic tank. Septic tank effluent will then gravity flow to a filter bed. A filter bed disposal system must be installed due to area constraints. SEPTIC TANK Septic tanks store the accumulated sludge, scum and effluent(clear zone)volumes, which in turn affect treatment of nitrogen within the tanks. In the following calculation,the pump-out interval factor times the QAVE times the peaking factor(PF)correlate the pump-out time interval in years with the recommended tank capacity. The peaking factor value for this project is estimated to be 2.5. Recommended tank capacity for a potential pump-out interval of three years after operation: 2.8(pump-out interval factor) (QAVE)x Peaking Factor(PF=2.5)=2.8 (280 gpd) x 2.5 = 1,960 gals. Proposed Septic Tank Capacity=2,000 gallon tank. The following calculation for .c - ' g is based upon detention time and also determines the septic tank capacity should a 2,000 gallons: Detention Time=2,000 gal total tank capacity x 0.70(30%volume lost to sludge/scum accumulation) 2.5 (Peaking factor)x 280 gpd(ADF) Detention Time=2.0 days. The minimum acceptable detention time is 1.0 days. Therefore,a 2,000 gallon septic tank is applicable for sufficient detention time with an adequate safety factor. I/ LEACHLINE/FILTER BED REQUIREMENT CALCULATIONS FOR KENNEL WASH-DOWNS, EMPLOYEES RESTROOM,WASHER MACHINE,AND KITCHEN WITH SINK/DISHWASHER: Base Tank Capacity= 1,200 gal. ADF=280 gpd Leachline Equivalent Requirement= 1,200 gallons BTC +280 ADF x 0.225 sandy silt Soil Factor(SF)at native soil-effluent interface=333 lineal feet of leachline(LFLL) required. 333 LFLL x 3 (filter bed sizing factor)=999 sq. ft. Filter Bed. 18 ft x 56 ft= 1,008 sq. ft. Filter Bed to be installed. PROPOSED FILTER BED DESIGN AND OPERATIONAL PARAMETERS: As effluent gravity flows from the septic tank, it will travel to the south end of the filter bed. Here the tight line will connect with the perforated piping network as depicted on the attached Septic System Plans. This perforated piping network will be placed over 12 inches of standard drain rock and installed as level as possible with the orifices in the four o'clock and eight o'clock positions. Two inches of drain rock are to be placed over the piping network. Filter fabric is then to be placed over the drain rock before backfilling with native soil to grade. As septic tank effluent flows into the piping network, it will cause effluent in the perforated piping to dribble out of the orifices for a relatively equal distribution throughout the filter bed, provided the piping network is installed as level as possible. 100%Reserve Replacement Area: The 100%replacement area can be accommodated in the northwest corner of the subject property as illustrated on the Septic System Plans. tl In