Built in 1957, the Louisville Metropolitan Sewer District's Western Flood Pump Station safeguards 138,000 west Louisville residences in the combined sewer (CSO) service area from flooding. As the first flood pump station activated when area flooding occurs, the Western Flood Pump Station (WFPS) is also the first full-scale renovation for any of the original Louisville area flood pump stations, which were built in the 1950s.
GRW was the lead design firm for the design-build of the 1.2 billion gallon per day (BGD) WFPS renovation project which involved replacement of seven vertical pumps (three 54,000 gpm pumps and four 162,000 gpm pumps), seven motors (three 450 Hp and four 1250 Hp), pump lubrication systems, bar screens and trash removal system, three 48-inch gate valves and flap gates, four 72-inch multi-shutter gates, a 30-ton bridge crane, and structural improvements to accommodate the new pumps and motors. The project also involved replacement of the existing HVAC system, roof, bathroom and office facilities.
The pump station electrical and instrumentation systems were also replaced including a backup 13,800 V electrical service from a different LG&E substation than the current electrical service, two 13.8/4.16 KV liquid-filled transformers each sized to operate the entire pump station load, a 13.8 KV/480 volt stepdown transformer for building service loads, a 5 KV class medium voltage motor control center with motor protective relays for control of the seven flood pumps, a seven step 3300 KVAR automatic power factor capacitor bank to maintain a lagging power factor above 80 percent, a local PLC to automatically control the pumps and remotely monitor the station from the Morris Forman Water Quality Treatment Center, pressure transducers to measure wet well level, resistance thermal detectors (RTDs) for pump bearings and motor windings, vibration monitors for the motors, and a hazardous/explosive gas detection system. All of this work occurred while the pump station remained in service with no more than one pump out of service at a time.
During design and construction, GRW worked closely with Louisville MSD and the US Army Corps of Engineers (USACE) to ensure project goals, such as a 50-year design life, were met. As a result, rigorous witness testing and inspection routines were implemented to ensure that each pump and motor component met the stringent equipment specification requirements before being shipped to the project site.