Section 58.01.16.441 - FACILITY AND DESIGN STANDARDS FOR MUNICIPAL WASTEWATER TREATMENT OR DISPOSAL FACILITIES: INDIVIDUAL RESIDENCE WASTEWATER PUMPING STATIONS01.General. Section 441 regulates individual residence pump stations, individual residence grinder pump stations, and individual residence septic tank effluent pump stations. However, this rule does not regulate grinder pumps or their vaults that are inside of individual residences or other structures. Certain individual residence wastewater pumping stations may be under the jurisdiction of the Idaho Division of Building Safety, Plumbing Bureau. For further defining and delineating of the Plumbing Bureau's and the Department's statutory and regulatory duties and responsibilities with respect to individual residence wastewater pumping stations, see the Memorandum of Understanding referred to in Section 008. a. Flooding. Wastewater pumping station structures and electrical and mechanical equipment shall be protected from physical damage by the one hundred (100) year flood. Wastewater pumping stations shall remain fully operational and accessible during the twenty-five (25) year flood. Local, state and federal flood plain regulations shall be considered.b. Accessibility and Security. The pumping station shall be accessible by maintenance vehicles during all weather conditions.02.Design. Design of wastewater pumping stations shall meet the applicable requirements of Subsections 441.02.a. through 441.02.c.a. Pumps. i. Multiple Units. Duplex pumps for individual residence wastewater pump stations are not required. However, for developments having five (5) or more similar facilities, one (1) working spare pump for each size shall be provided and be readily available at all times.ii. Pump Openings. Pumps handling raw wastewater shall be capable of passing spheres of at least three (3) inches in diameter or be a grinder pump.iii. Priming. The pump shall be placed so that, under normal operating conditions, it will operate under a positive suction head.b. Controls. Water level control sensing devices shall be designed to allow for automatic control of pumps.c. Valves. Suitable means to facilitate pump removal and to prevent backflow shall be provided. All shutoff and check valves shall be accessible for maintenance.03.Submersible Pump Stations - Special Considerations. a. Construction. Submersible pumps and motors shall be designed specifically for raw wastewater use, including totally submerged operation during a portion of each pumping cycle. An effective method to detect shaft seal failure or potential seal failure shall be provided.b. Pump Removal. Submersible pumps shall be readily removable and replaceable without personnel entering or dewatering the wet well, or disconnecting any piping in the wet well.c. Electrical Equipment. Section 009 provides a reference to the requirements of the National Electrical Code, compliance with which may be required by other law. i. Power Supply and Control Circuitry. 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.ii. Controls. The motor control center shall be located outside the wet well, be readily accessible, and be protected by a conduit seal or other appropriate measures to prevent the atmosphere of the wet well from gaining access to the control center. The seal shall be located so that the motor may be removed and electrically disconnected without disturbing the seal. When such equipment is exposed to weather, it is recommended that it meet the requirements of weatherproof equipment NEMA 3R or 4.iii. Power Cord. Pump motor power cords shall be designed for flexibility and serviceability under conditions of extra hard usage. Ground fault interruption protection shall be used to de-energize the circuit in the event of any failure in the electrical integrity of the cable. Power cord terminal fittings shall be corrosion-resistant and constructed in a manner to prevent the entry of moisture into the cable, shall be provided with strain relief appurtenances, and shall be designed to facilitate field connecting.04.Alarm Systems. Audio-visual alarm systems with a backup power source shall be provided for pumping stations. The alarm shall be activated in cases of wet well high water levels and shall be visible from the outside of the structure.05.Emergency Operation. The pumping station must be sized to allow for one (1) day's flow between the high water alarm and the building service invert or the pressure discharge pipe, whichever is closer to the high water alarm.06.Instructions and Equipment. Wastewater pumping stations shall be supplied with a complete set of operational instructions, including emergency procedures, maintenance schedules, tools, and such spare parts as may be necessary.07.Operation and Maintenance. An operation and maintenance manual shall be submitted to and approved by the Department as required by Section 425. Adherence to the terms of this approved manual shall be required. The owner shall be responsible for maintaining the wastewater facility in a manner that assures its designed operation.08.Force Mains. a. Velocity and Diameter. At design pumping rates, a cleansing velocity of at least two (2) feet per second shall be maintained.b. Special Construction. Force main construction near streams or water works structures and at water main crossings shall meet applicable provisions of Section 430.c. Design Friction Losses. i. Friction Coefficient. Friction losses through force mains shall be based on the Hazen and Williams formula or other acceptable methods. When the Hazen and Williams formula is used, the friction losses for varying values of "C" shall be evaluated for different types and ages of pipe.ii. Maximum Power Requirements. When initially installed, force mains will have a significantly higher "C" factor. The effect of the higher "C" factor shall be considered in calculating maximum power requirements and duty cycle time to prevent damage to the motor. The effects of higher discharge rates on selected pumps and downstream facilities shall also be considered.d. Identification. Where force mains are constructed of material which might cause the force main to be confused with potable water mains, the force main shall be appropriately identified using trench tape saying "raw sewage," "biohazard," or other appropriate wording.e. Leakage Testing. Leakage tests shall be specified including testing methods and leakage limits. Testing shall conform with Sections 401.3.6 and 505.3.3 of the "Idaho Standards for Public Works Construction," incorporated by reference into these rules at Section 004.f. Thrust Blocking. Thrust blocking shall conform with Sections 401.3.4 of the "Idaho Standards for Public Works Construction," incorporated by reference into these rules at Section 004.g. Maintenance Considerations. Isolation valves shall be used if force mains connect into a common force main.h. Cover. Force mains shall be covered with sufficient earth or other insulation to prevent freezing or other physical damage.Idaho Admin. Code r. 58.01.16.441