Laserfiche WebLink
2~ <br /> <br />3. <br /> <br />[Refer to OAR 340-73-O55] <br /> <br />The pump shall be placed within a corrosion resistant screen that <br />extends above the maxim~um effluent level. The use of a screen is <br />not necessary if the pump does not discharge into pressurized <br />distribution piping, and the pump bas a non-cloy impeller capable <br />of pa~sing a 2/4" diameter solid sphere, <br />The screen sha1~ have at least 12 square feet of surface area, <br /> with 1/Sth inch openings. <br /> A screen is always required in a do~ing septic tank. (S~e OAR <br /> 340-73-030) <br /> <br />VALVING <br /> <br />A gate valve in installed in the pressure line set above the <br />inlet pipe in a readily accessible location and position, within <br />approximately 12 inches of the rimer cover (see diagram). <br />A check valve is installed between the pump and the gate valve. <br />A union disconnect of noncorrosive material is installed between <br />the check and gate valves above the inlet pipe in a readily <br />accessible location and position, within approximately 12 inches <br />of the riser cover (see diagram), <br />For the purposes of preventing pump air-lock, a 1/8" or larger <br />orifice is recommended to be installed (drilled) in the pressure <br />line below the pump "OPF" level. This may be required by the pump <br />manufacturer's installation instructions. <br /> <br />PRESSURE PIPING <br /> <br />Minimum 2" diameter. <br />Must meet'or exceed standards for Class 160 PVC 1120 as identi- <br />fied in ASTM Standard D-2241. <br />Piping shall be uniformly supported along the trench bottom. <br />Minimum depth of installation shall be 18" or below frost line <br />whichever is greater. <br />Must be baffled at point of discharge: <br />a. Serial distribution: Enter the first drop box with pressure <br /> line elbowed down below the overflow header outlet, <br />b. ~qual distribution: A murge box is recommended with the <br /> pressube pipe elbowed down below the outlet to the mas~er <br /> distribution box. <br /> An 14 gauge, green colored tracer wire shall be placed above <br /> piping when crossing property lines or entering public property <br /> or rights-of-way. A tracer wire should also be installed from the <br /> dosing tank manhole lid to the first box of the disposal field. <br /> <br />.S__ETBA~KS [minimum setbacks from dosing tank, with exceptions for pres- <br />sure transport piping] <br /> <br />1- <br />2. <br /> 3. <br />4. <br /> <br />50' from creeks, ponds~ streams, etc.; springs and wells. <br />25' from doWnslope ground water interceptors and cuts manmade. <br />10' from water lines, property lines a~d escarpments. <br /> 5' from building foundations, septic tanks and disposal fields. <br /> <br /> <br />