(A) General. The city will not accept any newly constructed pumping stations not designed according to the sewage pump station design standards and specifications on file at the Wastewater Division Office. Pump station design and specifications will be strictly enforced.
(B) Minimum requirements for new pumping stations.
(1) The float switch shall be a simple, dependable, level-sensing automatic pump or alarm control device that operates reliably in sewage wet wells, water reservoirs, ditches or process vats. The float body shall be of high density polyethylene and the cable jacket shall be made of synthetic rubber for outstanding performance in a wide-range of corrosive environments. Each float should sense the movement of the liquid level past its mounting elevation. It should turn on and off at essentially the same point on a rising or falling level. Single floats shall be used for differential control of pumps. Floats should contain one or two mercury switches each of which can be normally-opened or normally closed. A weight kit should be available for individual float suspension.
(2) The float hangers and pump lifting bales shall be made of 316 stainless steel.
(3) The electric cabinets shall be constructed of 316 stainless steel.
(4) Conduit for float cables shall be of one and one-half inch PVC. Each pump cable shall have its own conduit of adequate size and shall be of PVC.
(5) The valve vault shall have a two-inch PVC drain to the wet well with a PVC check valve and a trap to prevent liquid and odors from backing into the valve vault.
(6) Check valves shall be the rubber flapper swing check valve. It should be simple in design, have no moving parts and the flapper shall not pivot from the hinge pin, it should flex to open. Check valves should be non-slamming in design because the flapper should only travel 35 degrees to reach the 45-degree seat and the flapper should be spring loaded with resiliency, so it closes before column reversal or near zero velocity, hence, the severity of slamming is negligible. Without moving parts to wear out, the rubber flapper check should be virtually maintenance free.
(7) Pump guide rails shall be 316 stainless steel.
(8) There shall be an auxiliary pump connection to the force main.
(9) An eight-foot high chain link fence shall surround the station wet well, valve box, and electrical control boxes. A minimum 25-foot by 25-foot area with a double swing 13-foot gate. The fence shall be of two-ounce aluminum coated six-gauge fabric.
(10) An auxiliary transfer switch and cable connection shall be provided that is adaptable to the city portable generator.
(11) Pumps (minimum duplex station). The pump(s) shall be capable of handling raw, unscreened wastewater. The discharge connection elbow shall be permanently installed in the wet well along with the discharge piping. The pump(s) shall be automatically connected to the discharge connection elbow when lowered into place, and shall be easily removed for inspection or service. There shall be no need for personnel to enter pump well. Sealing of the pumping unit to the discharge connection elbow shall be accomplished by a simple linear downward motion of the pump. A sliding guide bracket shall be an integral part of the pump unit. The entire weight of the pumping unit shall be guided by no less than two guide bars and pressed tightly against the discharge connection elbow with metal-to-metal contact. No portion of the pump shall bear directly on the floor of the sump. The pump, with its appurtenances and cable, shall be capable of continuous submergence underwater without loss of watertight integrity to a depth of 65 feet and shall meet requirements of the National Electrical Code for such units. An effective method to detect shaft seal failure or potential seal failure shall be provided. Pump suction and discharge openings shall be two inches minimum and the pump shall be capable of passing a three-inch sphere. The electrical system and components, including motors, lights, cables, conduits, switchboxes and the like shall comply with NEC requirements for Class 1, Group D, Division 1 locations.
(12) Aluminum access frame(s) and door(s), minimum rated 150 lbs./sq. ft., complete with hinged and flush locking mechanism and level sensor(s) cable holder. Frame shall be securely placed, mounted above the pump(s) or valves. Each door shall have a safety handle to maintain the door in the open position. Doors shall be of skid proof design. A sliding nut-tray shall be incorporated into the design of the access frame. The sliding nut-tray shall be located on three sides of the frame to facilitate the mounting and moving of the upper guide bar, brackets and cable holder. Furnish and install upper guide bar brackets, guide bar, galvanized chain and cable holder.
(13) An access road shall be provided with sufficient width for the city’s lift station maintenance truck.
(14) Force main shall be four inches in diameter or larger.
(15) Wet well shall have storage capacity for one-day flow.
(1960 Code, § 38-4-8) (Ord. 5334, passed 10-17-1994)