1986-07-21 Septic System Report - Laserfiche WebLink

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CITY OF OR ON 0 GENERAL CONSTRUCTION REQUIRFYIENTS FILL TRENCH DRAINFIELD SYSTEM TO BE USED WHERE: Seasonal perched water table is deeper than 5 feet. Percolation rate is between 60 and 90 min. per inch. Slope is 18% or less. CONNECTION TO HOUSE House to tanks may be PVC (ASTM D-3034 or better), cast iron or clay tile. PVC should be sand -bedded in flat runs over long distances. No outside air test required but joints must be tight. TANKS Two (2) precast concrete tanks are required. Min. size 1000 gal. and 750 gal.; we recommend 2 1000's. Tanks must have 20" manhole riser to within 12" of final grade, and at leas:. one 4"-6" inspection stack to surface. Baffles must be ac d resistant and may be plastic, fiberglass, or precast with tank. DRA INFIELD Trenches in top 3' of natural undisturbed soil. Not in cut or fill areas. Place at least 6" and not more than 12" or sand oma -.Zoe} -between bottom of scarified trench and =ter rock. Maximum width 36". Maximum length per line 1001. Rock 6-12" below pipe and 2" over top. Tile may be PVC or plastic with It," holes every 36" or closer. Use hay or un- treated building paper over rock. Backfill - maximum depth 36", minimum depth 8", 12-24" preferred. Trench bottom must be level or have slope of not more than 4" per 1001. DISTRIBUTION Drop boxes or distribution box depending on layout and topography. A pre.G,ire distribution system using 13-15" pipe and pump from t, .ks is high1Q recommended for the fill trench system. -• r Ok PUMPING : If pumping is needed between tank and drainfield, pump should go in a 3rd tank or in baffled chamber in 2nd tank. The idea is to retain the 2nd tanks capacity for solids retention. An alarm device and reserve capacity of one days sewage flow are required. QUESTIONS ? CALL THL SEPTIC SYSTEM INSPECTOR AT 473-7357•