Lime sludge is one of the byproducts of the water purification process for drinking water. For many years, Oklahoma City’s Hefner Water Treatment Plant operated a lagoon system for lime sludge with a maximum capacity of 100 million gallons per day (MGD). With high maintenance costs, a landlocked location and operational issues, the City sought to move beyond its existing system.
STV provided preliminary design, final design and construction phase services for the City. The firm’s initial evaluation of multiple dewatering alternatives selected conversion to a belt filter press mechanical dewatering system. Maintaining the current lagoon system required a 30-year net present value (NPV) of approximately $82 million; in contrast, the selected mechanical dewatering alternative produced a 30-year NPV of approximately $62 million. The mechanical dewatering system is designed for a water treatment flow of 150 MGD and can be easily expanded to 200 MGD in the future.
With an accelerated design and construction schedule, STV’s design team delivered on its shared goal with the City of Oklahoma to provide quality drinking water to residents. The City’s forward-thinking decision to mechanically dewater solids residuals with belt filter presses created the largest lime solid dewatering installation in the state of Oklahoma.
$20m
annual client cost savings
150 MGD
increased capacity
