Nebraska Administrative Code
Topic - ENVIRONMENT AND ENERGY
Title 123 - NEBRASKA DEPARTMENT OF ENVIRONMENTAL QUALITY
Chapter 5 - DESIGN STANDARDS AND SPECIFICATIONS
Section 123-5-003 - Lift Stations
Current through March 20, 2024
003.01 Lift stations will be protected from vandalism by fencing or lockable structures. Lift stations will be located so they are accessible to maintenance vehicles during all times of the year.
003.02 Where ground water is encountered, lift stations will be designed to withstand buoyant forces.
003.03 Multiple pumps will be provided for all lift stations, except where four or fewer service connections are served and the total flow is less than 2000 gallons per day. Where two pumps are provided each will be capable of pumping the peak hourly flow. Where three or more pumps are provided, they will be sized to pump the peak hourly flow when the largest pump is out of service. The control system will have the ability to automatically alternate the pumps in operation.
003.04 Lift stations pumping raw wastewater will be designed to achieve a velocity of at least 2.0 feet per second in the force main.
003.05 Pumps handling raw wastewater will have suction and discharge openings at least four inches in diameter and be capable of pumping solid spheres at least three inches in diameter. This requirement does not apply to grinder pumps. Each pump will have an individual intake opening.
003.06 For custom built wet wells, the wet well floors will be sloped toward the pump inlets to minimize the accumulation of grit and wastewater solids.
003.07 Check valves and shutoff valves will be placed on the discharge pipe of each pump with the check valve located between the pump and the shutoff valve. Check valves will be located on horizontal pipe sections, except for ball check valves, which may be located on vertical sections. For satellite lift stations, the check valves and shut-off valves will be located in a separate chamber out of the wet well. Check valves that are an integral part of the pump may be used if the pump and valve can be removed from the wet well without maintenance personnel entering the wet well.
003.08 Where a valve pit is installed adjacent to a lift station it will include a drain line back to the lift station wet well. The drain line will include a flap valve to prevent gases from entering the valve pit.
003.09 Where a wet well/dry well type lift station is used, the dry well will be sealed off from the wet well so that wastewater and sewer gases cannot enter the dry well.
003.10 Where dry wells are located below the ground surface, permanent mechanical ventilation will be provided. Wet wells will be provided with permanent mechanical ventilation if valves, screens, or other equipment is located in the wet well that must be inspected and maintained by personnel entering the wet well.
003.11 When continuous mechanical ventilation is provided in wet wells, it will provide at least 12 complete air changes per hour. Continuous ventilation in dry wells will provide at least six complete air changes per hour. Intermittent mechanical ventilation, in either case, will provide at least 30 air changes per hour. The direction of forced air will be into the wet well or dry well.
003.12 Each satellite lift station will be equipped with an alarm system that is activated by power failure or a high water level. If the lift station serves at least 25 service connections and less than 24 hours of storage capacity exists at the lift station and in the collection system before a backup or sanitary sewer overflow occurs, the alarm will be telemetered to the responsible parties 24-hours a day. Where less than 25 service connections exist or where 24 hours of storage capacity is provided an audio and visual alarm will be provided.
003.13 Lift stations must be provided with emergency provisions to avoid backups into basements or sanitary sewer overflows. One of the following emergency provisions will be provided at each lift station:
003.14 All satellite lift stations will be designed with a riser pipe on the downstream force main. The riser pipe will be fitted with quick connection couplings and shutoff valves, as necessary, to be used in emergencies with a portable pump.
