Monday, September 9, 2024
11:30 AM - 12:00 PM
Between a Tank and a Hard Place – Serving Two Tanks with One Pump Station
Water Supply

Kentucky American (KAW) owns more than 20 booster pump stations throughout their Central Kentucky service area, serving a population of about 500,000 in portions of Franklin, Bourbon, Scott, Owen and Fayette Counties. Many of these booster stations are housed in concrete vaults with most of the equipment and piping located below-grade. These vaults often qualify for Confined Space Entry requiring Maintenance staff to complete specific OSHA training in order to access these areas. Even with the special training and tools, these vaults are difficult to work in due to limited space, insufficient lighting, and even pests. Many are reaching the end of their useful lives and are in need of significant repairs or wholesale replacement. To address these issues, KAW initiated a program to replace these stations with above-ground facilities that feature updated equipment, additional sensors and safe access for staff. Of the 20 pump stations in KAW’s system, Cox Street is one of the oldest and most unique sites. There are two storage tanks (one steel reservoir and one elevated steel spheroid) that provide the suction head and storage for two separate pump station vaults - Cox Ground and Cox Elevated. The tanks were constructed between 1948 and 1955 and both have overflows that are lower than the present-day hydraulic grade, meaning they are unable to provide flow into the system without the assistance of the pump stations. This also means that in order to prevent them from overflowing, each tank requires dedicated altitude valves which are located in two more below-grade, concrete vaults. These assets are all packed into a half-acre lot located in downtown Lexington with a nearly 20-foot grade change across the site that required a concrete staircase to access the site on foot. KAW engaged Stantec to design a new pump station within the existing site that could replace all four of the existing vaults (pump stations and altitude valves) and serve both tanks at different hydraulic heads. This required considerable input from the Operations and Maintenance staff regarding the layout of equipment and orientation on-site and significant coordination with the pump station designer, Engineered Fluids Inc. (EFI), regarding the station hydraulics and piping design. This coordination extended into Construction where the Contractor (CJ Hughes) had to phase activities that allowed work to be completed while keeping access, power and communication to the existing facilities in place until the new station could be started and tested.