City of Paris – Southeast Lift Station
The City of Paris built a lift station to serve the southeast portion of town in the mid 1960’s. As development increased in that portion of town, so did the deterioration of the sewage collection system.
The combination of increased development and increase deterioration of the collection system lead to overflows in the collection system. A flow equalization basin was installed in the mid 1980’s, but nuisance conditions associated with the basin were problematic. As time went on, conditions grew worse—which resulted in additional overflows.
Another issue was that the flowrate of the existing lift station was not adequate to achieve “flushing velocity” in the force main–and solids settled out as a result. The settled solids decomposed under anaerobic conditions in the force main; resulting in extreme levels of hydrogen sulfide immediately downstream of the force main discharge point.
Hayter Engineering was hired to design a replacement lift station. The goal was to increase the capacity of the station so that the overflows in the collection system were eliminated and so that the flowrate in the force main was high enough to result in a flushing velocity.
The design consisted of the following components:
• Two 3,000 GPM (4.32 MGD) 140 HP submersible pumps
• Motor Control Center (MCC) for 480V / 3-Phase power
• Concrete wetwell structure
• All components and piping for 3 pumps (2 current and 1 future)
• Valve vault with 12” plug valves and check valves
• Removable trash basket with motorized hoist system for removal
• Hoist and trolley system with superstructure for pump removal
• Strap-on ultrasonic flow meter in a concrete vault
• Gravel access road, site work, and manproof chain link fence
• 800 feet of 12” gravity sewer line
• Over 3,700 feet of 18” force main with 2 air/vacuum valve vaults
• 24” road bore and casting