11-14-2016 Council Packet - Laserfiche WebLink

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10 or more Sewage tanks shall be sized as other establishments per Minnesota Rules chapter 7080. c. Pumping stations. In order to standardize installation and electrical connection methods, the following pumping station requirements must be met in addition to Minnesota Rules chapter 7080: 1. Electrical connection. A watertight, lockable electrical box must be mounted on a four -inch -by -four -inch treated redwood or cedar post. ii. All electrical connections shall be made within the box. Pump connection must not be made using a direct line (plug-in only). Wire entry to the electrical box shall be sealed with a watertight material such as foam or putty. iii. Alarm and pump floats shall be on separate electrical circuits. iv. Electrical wire from the power supply must not run over any tanks but must be laid beside the tanks and placed in conduit along the electrical post. v. Electrical cords from the pump and floats must be run through a two-inch PVC (or equivalent) conduit (schedule 80) with a one -inch gap between the conduit and the electrical box. Electrical cords must not run through or under the manhole cover. Wires must not have ground contact. 2. Pumping chamber. Pressure pipe exiting the pumping chamber must be laid on a uniform slope up to the soil treatment area for proper drain back. The pressure pipe must be sleeved inside a larger diameter pipe for additional support if spanning ground that has been excavated. If the pipe at the tank must be lower than union to get elevation for drain back, a one -quarter -inch weep hole must be used. ii. When the soil depth above the pressure distribution pipe is less than 3% feet, insulation must be added to achieve an insulating factor equal to 3% feet of soil to decrease the potential for freezing (Styrofoam or concentric piping are acceptable methods). Piping under hardcover, such as tennis courts or driveways, shall be insulated pipe or equivalent. iii. A reserve capacity equaling 75 percent of the anticipated daily flow must be allowed in the pumping chamber between the alarm activation level and the pump tank inlet. d. Drainfields. 1. Trenches. Trenches must meet Minnesota Rules chapter 7080. 2. Mounds and at -grades. Mounds and at -grades must meet specifications per Minnesota Rules chapter 7080. (3) Compliance standards. a. A new system shall be located, designed and constructed as a code system. Page 3