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 June 17, 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:
003.13A The lift station will
  be connected to two independent electrical substations;
003.13B A storage capacity of 24 hours of
  flow is provided in the upstream sewer system or by storage structures, before
  a backup or sanitary sewer overflow occurs;
003.13C A permanent engine driven electrical
  generator is installed;
003.13D A
  portable electrical generator is kept available within one hour of travel time
  and two hours of storage capacity exists before a backup or sanitary sewer
  overflow occurs; or
003.13E A
  portable pump and adequate hose or piping is kept available within one hour of
  travel time and two hours of storage capacity exists before a backup or
  sanitary sewer overflow occurs.
003.13F Another method approved by the
  Department.