The City of Toccoa, Ga., needed to retrofit or replace an existing underground lift station that pumps raw sewage to a holding pond at 2500 gpm with a head of 65 ft. The systems three below-grade pumps were unable to effectively handle high flows at peak times. Utility personnel also were constantly being exposed to raw sewage fumes while inspecting the underground pumps during maintenance, a common problem with below-ground pump stations.
A Patterson Pump Co. MPVT™ multi-purpose vertical turbine pump was recommended for retrofitting the operation. City utility officials were convinced that the single, above ground pump would do the same job as the three dry pit, non-clog pumps, and be able to handle higher flows at peak times. With the pump discharge, motor and controller all being above grade, maintenance could be done in a clean and safe environment above the wet well.
The city selected a 12 inch pump driven by a 50 hp vertical hollow shaft motor. The pump is constructed of cast iron and capable of pumping a maximum of 4,500 gpm, with solids up to three inches in size.
To install the new vertical turbine pump, a hole was cut in the wet well and the pump was dropped in. Only minor piping changes had to be made to complete the installation.
“Retrofitting our old lift station with a Patterson MPVT pump was unbelievably easy,” said Bill DeFoor, utilities director. “We simply set it down and framed it.”
“We now can check proper operation and do any necessary maintenance above ground,” he said. “Thats not only a better working condition, its a real time saver.”
The MPVT pump uses a standard, off-the-shelf motor, offering the highest efficiency while providing lower operating costs. It has a life span up to four times longer than its below grade competitors. No special tools or maintenance personnel are required to operate and repair the pump.
Bearings can be replaced without costly and time-consuming teardown of the entire pumping unit, and a special impeller-to-shaft mounting allows fast removal. The pump also features high hydraulic performance and the lowest rotor vibration and noise levels in the wastewater treatment market.
