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SCREEN [Refer to OAR 340-737055] 1. The pump shall be placed within a corrosion resistant screen that extends above the maximum effluent level. The use of a ~creen is not necessary if the pump does not discharge into pressurized distribution piping, and the pump kas a non-clog impeller capable of Passing a 3/4" diameter solid sphere. 2. The screen shall have at least 12 square feet of surface area, with 1/Sth inch openings. 3. A screen is always required in a dosing septic tank. (See OAR 340-73-030) VALVING 1. A gate valve in installed in the pressure line set above the inlet pipe in a readily accessible location and position, within approximately 12 inches of the riser cover (see diagram). 2. A check valve is installed between the pump and the gate valve. 3. A union disconnect of noncorrosive material is installed between the check and gate valves above the inlet pipe in a readily accessible location and position, within approximately 12 inches of the riser cover (see diagram). 4. For the purposes of preventing pump air-lock, a 1/8" or larger orifice is recommended to be installed (drilled) in the pressure line below the pump "OFF" level. This may be required by the pump manufacturer's installation instructions. PRESSURE PIPING Minimum 2" diameter. M~st meet'or exceed standards for Class 160 PVC 1120 as identi- fied in ASTM Standard D-2241. Piping shall be uniformly supported along the trench bottom. Minimum depth of installation shall be 18" or below frost line whichever is greater. Must be baffled at point of discharge: a. Serial distribution: Enter the first drop box with pressure line elbowed down below the overflow header outlet. b. Equal distribution: A surge box is recommended with the pressure pipe elbowed down below the outlet to the master distribution box. An 14 gauge, green colored tracer wire shall be placed above piping when crossing property lines or entering public property or rights-of-way. A tracer wire should also be installed from the dosing tank manhole lid to the first box of the disposal field. SETBACKS [minimum setbacks from dosing tank, with exceptions for pres- sure transport piping] 2. 3. 4. 50' from creeks, ponds, streams, etc.; springs and wells. 25' from downslope ground water interceptors and cuts manmade. 10' from water lines, property lines and escarpments. $' from building foundations, septic tanks and disposal fields.