Pump Station Requirements
The most efficient method for collecting wastewater is by gravity through manholes and sewer lines. A gravity sewer system does not have any mechanical parts and does not require electricity. Unfortunately, from time to time it is necessary to install and operate a pump station so that wastewater can be lifted over a hill, out of a valley, or around an obstruction. All pump stations are labor intensive, costly for the City to operate and maintain, and if left unattended can be the source of sewer spills. As a part of the City’s on-going effort to prevent sewer spills, protect the environment, and protect personnel, the City has adopted a set of Wastewater Pumping Station Specifications. (These specifications can be downloaded using Acrobat Reader). Click here to download a copy.
The City has attempted to standardize the equipment used in all pump stations so that there will be a large spare parts inventory at all times. A list of approved vendors is available upon request. Each station must meet certain minimum requirements as specified by the City. Typically, the City allows ITT Flygt Pumps or an approved equivalent. www.flygtus.com. The use of above ground type pumps are strictly prohibited
Among the specifications pertaining to pump station design is the requirement for SCADA or Supervisory Control And Data Acquisition. The SCADA system transmits all pertinent information about the pump station to the Advanced Water Reclamation Facility (AWRF) where a central computer tracks the station’s performance and alerts facility operators to certain failures and conditions. A graphic on the computer screen at the AWRF shows station conditions in real-time and allows facility operators to make a virtual visit to the station several times each day without actually driving to it. See www.jkduren.com for more information.
In addition to the SCADA system, each City pump station must include an auto-dialer. This “voice box” of the station transmits a vocal message across the phone lines to several different telephone numbers each time a problem arises (power goes off) or ceases (power is restored). Please see www.racoman.com/products.html for more information.
An emergency back up generator is a critical piece of equipment for each pump station and is now required by the Georgia Environmental Protection Division (EPD). The City is in the EPD’s “zero tolerance” zone and faces stiff fines if any wastewater is released into the environment. See www.dnr.state.ga.us/dnr/environ/ for more information. The City requires that all generators below and including 100 KVA be powered by natural gas and that all generators above 100 KVA be powered by diesel. Each generator must have an automatic transfer switch and be capable of automatic exercise cycling. More precise specifications are available by downloading the City’s Wastewater Pumping Station Specifications.
An emergency, complete pump station bypass is required for each station. This bypass piping system will allow the City to place the suction end of a large portable pump down in the wetwell, and connect the discharge of the portable pump to the bypass standpipe. Personnel can then pump the sewage through the forcemain to the next manhole.
Wetwells must be coated with a two-part epoxy. As you can see, this wetwell is being coated and has almost been completed.