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Oklahoma Administrative Code (Last Updated: March 11, 2021) |
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TITLE 252. Department of Environmental Quality |
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Chapter 656. Water Pollution Control Facility Construction Standards |
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Subchapter 7. Pump Station Standards |
SECTION 252:656-7-3. Submersible pump stations
Latest version.
- Submersible pump stations shall meet the applicable requirements under OAC 252:656-7-1 (design), except as provided in this section.(1) Construction. Submersible pumps and motors must be designed specifically for raw sewage use, including totally submerged operation during a portion of each pumping cycle. Provide an effective method to detect shaft seal failure or potential seal failure. The motor shall be of squirrel-cage type design without brushes or other arc-producing mechanisms.(2) Pump removal. Submersible pumps shall be readily removable and replaceable without dewatering the wet well or manually disconnecting any piping in the wet well.(3) Electrical.(A) Power supply and control. Electrical supply, control and alarm circuits shall be designed to provide strain relief and to allow disconnection from outside the wet well. Terminals and connectors shall be protected from corrosion by location outside the wet well or through use of watertight seals. If the location is not sheltered, use weatherproof equipment.(B) Controls. Locate the motor center outside the wet well. Protect it by a conduit seal or other appropriate measures meeting National Electrical Code requirements to prevent the atmosphere of the wet well from gaining access to the control center. The seal shall be so located that the motor may be removed and electrically disconnected without disturbing the seal.(C) Power cord. Pump motor power cords shall be designed for flexibility and serviceability under conditions of extra hard usage and shall meet the requirements of the National Electrical Code standards for flexible cords in wastewater pump stations. Power cord terminal fittings shall be corrosion-resistant and constructed in a manner to prevent the entry of moisture into the cable, provided with strain relief appurtenances and designed to facilitate field connection.(4) Valves. Valves for force mains shall be located outside the wet well in a separate enclosure. Provide drain systems for below-ground enclosures. If the valve enclosure is drained to the wet well, include a method to prevent sewage from entering the enclosure during surcharged wet well conditions.