Oklahoma City expands filtration capability with glass-fused-to-steel tank
Oklahoma City has undertaken systematic, thoughtful planning to meet the demands of a growing city. Built in the 1920s, the Overholser Water Treatment Plant is a monument to the past with a timeless mandate: to supply clean water during periods of high demand, especially the scorching Oklahoma summers. A critical function of the plant is filtration, during which the water passes through a sand and carbon filter. To clean the filter, the flow is reversed; the filters are backwashed and the residual material is removed to a settling lagoon.
As the city grew and demand increased, so did the stress on the plant’s filtration system. Increased volume meant the filter required more cleaning, but the tank housing the filter was undersized. It was recommended that the city replace the old tank with an Aquastore glass-fused-to-steel storage tank. Compared to concrete or welded tanks, the Aquastore tank offers a factory-applied silica glass coating that forms a hard, inert barrier on both the interior and exterior surfaces, guarding against weather and corrosion. Using a sidewall erection process, the panels are bolted together, forming a ring. When completed, the ring is lifted with jacks so the next ring can be assembled directly underneath. Crews don’t have to leave the ground, and the whole process takes as little as 4 ft of space beyond the tank's foundation, offering a safe, quick solution to the construction process.
With the new tank and its 300,000-gal capacity, backwashing takes about 15 minutes, with enough water left in the tank to backwash another filter.
The Oklahoma City Utilities Department tests the city’s water at three treatment plants every two hours, exceeding the regulatory requirement of every four hours. Residents may not realize it, but their water quality is ensured by a leading-edge filtration system and cutting edge storage solution.