In an effort to improve the reliability of sewer lift stations throughout the community, the City of McPherson recently invested $135,000 in backup generators. The investment replaces a single trailer mounted generator purchased in 1977, which was used to supply emergency power to six lift stations in the event of a power failure. The 40-year-old system provided challenges during major power outages, including the need to travel from station to station for repetitive pumping to keep wastewater flowing in the pipes.
Backup generators are important to a community’s overall infrastructure. According to Michael Wagner, McPherson Wastewater Superintendent, sewer lines function by gravity. The City’s sewer system is composed of different drainage areas or basins that meet in one particular spot where the sewage collects in a large underground tank referred to as a wetwell. This is where the lift station is located, and a series of electric pumps “lift” the sewage from the wetwell up to a new pipe that allows for gravity feed. If the pumps lose power for any length of time, the sewage will start backing up in the pipes. Ultimately, the pipes run out of storage capacity and sewage will start backing up in basement floor drains, toilets, bathtubs and shower drains.
“This project was a substantial capital investment but, in my opinion, one of the best things we could do to help ensure that the public’s property is protected from damage due to sewer backups,” said Wagner. The new system includes the installation of permanent diesel powered generators at each lift station. “Having generators at each station and designed to automatically startup and supply power to the stations immediately upon loss of power ensures virtually no interruption of sewer services to homes,” explained Wagner.
The generator and lift station status are connected via radio telemetry to the treatment plant computer system. This allows wastewater staff to easily monitor the status of every station from the treatment plant or their cell phones, resulting in efficient response and manpower in the event there is a problem needing immediate attention.