SU0002167 SSNL - Laserfiche WebLink

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FILL PLACEMENT: Fill material should be placed on the upslope edges (Nearest the septic tanks) of the plowed area first. If possible, minimize traffic in the downslope area. Positioning of fill material can be accomplished by the most effective means. Importation of fill material should continue with as little compaction as possible until the height of the fill material is at the elevation of the top of the absorption bed. ABSORPTION BED AND DISTRIBUTION NETWORK PLACEMENT: Carefully place the coarse aggregate (314 - 2 inch) in the bed, on top of the fill material. Prevent ruts from forming in the bottom of the bed. Level the aggregate to a depth of six inches.' Assemble the distribution network on top of the aggregate. The laterals should be laid level. The manifold should be situated so that it will drain between doses, either out through the laterals or back into the pump or dosing chamber of the third septic tank. Place three inches of aggregate over the top of the distribution network. 4 COVERING OVER THE ABSORPTION BED: Straw should be used as a backfill material over the coarse aggregate absorption bed to a depth of at least one foot in the center of the distribution network. The on-site clay material may be used over the top of the straw and the sandy loam fill material to a depth of at least six inches. This clay material may be placed in two lifts of three inches each. After each lift emplacement, lightly water the clay material to compact it. Allow native vegetation to grow over this covering. PRESSURE DISTRIBUTION NETWORK DESIGN FOR THE PROPOSED MOUND LATERAL LENGTH: A central manifold system design may be used for both the primary I lateral system and the 100%replacement system: 100 ft absorption bed len tg_h = 50 ft/lateral x 8 (includes 100% repl. area) — 400 ft 2 LATERAL DIAMETER: 1.5 inch diameter based upon the lateral length and hole diameter and spacing. HOLE DIAMETER AND SPACING FOR LATERALS: For anticipated wastewater flows, 114 inch diameter holes spaced every 48 inches may be used. LATERAL DISCHARGE RATE: A 2 ft head should be maintained within the laterals. With 114 dia holes and 2 ft of head, discharge rate to be 1.04 gpm. Number of holes per lateral = 13 13 holes/lateral x 1.04 gpm= 14 gpm/lateral MANIFOLD LENGTH AND SIZE: Incorporating the 100%replacement absorption bed area and ten feet between each lateral, total manifold length through the beds will be: 2 5+10+5+15+5+10 = 50 ft+ approximately 30 ft from the third septic tank dosing chamber= 80 ft Delivery pipe and manifold should be 3 inches in diameter, Environmental Health may stipulate use of ABS pipe and not PVC for delivery and manifold. PUMP REQUIREMENTS: Assuming the following: Elevation head= 9 ft+2 ft pressure to be maintained + 1 ft friction loss = 12 ft of head. 4 laterals (excludes 100%replacement laterals) x 14 gpm/lateral = 56 gpm. Therefore,the pump must be capable of delivering at least 56 gpm. against 12 ft of head. A filtered pump vault (FPV)must be used with an alarm system and controls. vaffey Ag Ppeamh