the steadily growing population and expanding commercial base within the city of cedar falls caused the city’s sewer system to have capacity issues. in 2006, the city asked snyder & associates to examine the bluff street lift station and the sanitary sewer collection system that drained to it. that analysis led to the development of a bluff street lift station drainage area wastewater master plan which examined the existing sanitary capacity, the likelihood for future growth, and the ability of the current system to handle existing and future sewer flows. the city proceeded with plans to replace the existing bluff street lift station and construct a new 17th street lift station to increase sewage pumping capacity and meet long-term needs of the growing community.
the 17th street lift station was designed to increase sewage pumping capacity from 17,000-gallons per minute (gpm) to 24,000 gpm with capacity for additional upgrades in the future to 37,500 gpm. the new facility includes:
- screening to protect lift station pumps from damage
- a self-cleaning component for the wet-well
- four pumps capable of delivering less than 1,000 gpm each and at least 24,000 gpm when three are operating in parallel
- emergency power in the lift station
- increased flood protection by making the lowest access to the facility more than two-feet higher than the 1 percent annual chance flood event, also referred to as the 100-year flood, and one foot higher than the previously recorded high water level in the area, which occurred during the 2008 flood.
gates and bar screens.
the new lift station has provisions for adding a fifth pump and upgrading the new pumps in the future to meet growing system demands. additionally, space was reserved for carbon scrubbers to be added as needed in the future to meet enhanced environmental requirements or neighborhood needs. the existing force main was utilized while still increasing pumping capacity by more than 40 percent. the existing lift station is to be recommissioned for use by the fire department for testing equipment.
the new facility exceeded the project goal by delivering flows below the requested 1,400 gpm minimum. optimum performance was demonstrated during the summer of 2013 when a drought reduced the flow rate to less than 1,000 gpm and continuous sewage flows to the treatment plant were maintained. additionally, the project was constructed approximately $400,000 (5 percent) under budget.
