Case Studies

Expanding Expectations

Rural Illinois water district uses glass-fused-to-steel storage tanks to prepare for growth
Aug. 8, 2018
4 min read

Ron Popeil coined the phrase “set it and forget it” to sell his kitchen gadgets. But the phrase applies to more than slow-roasting a chicken.

Take water storage, for example. A rural district serving a vast area with limited resources and staff must be able to trust its equipment. It wants to know its tanks and pumps are operating 24/7, month-to-month and year-to-year because it does not have the time to constantly check on them.

The Solution

The Aquastore tank from CST was designed with this in mind, and districts such as Millstone in southern Illinois utilize it. District Manager Ken Richards needs to ensure every one of his 2,400 customers spread throughout a 2,080-sq-mile area is satisfied. Proper storage is critical to water quality, and Richards relies on Aquastore because it offers durability, reliability and low maintenance.

In fact, Millstone has an Aquastore tank that is over 20 years old. It has performed well, so the district opted to buy another one. 

“We took it offline for retooling and decided to build a second tank to meet our long-term demand,” Richards said. “We put the new tank online to handle storage while the old one was undergoing maintenance.”

Richards says workers did not have to detach a single panel for retooling, which saves time and money. Not having to repaint also adds to savings.

“Typically, repainting a tank has to be done in the summer, and you need to plan for roughly three months of downtime,” said Dave Hemauer, project manager at Cady Aquastore. “But it took only nine days after the tank was drained and washed out to rehab and make improvements to the older Aquastore tank. After a few days of sealer curing time, the tank was ready for sanitizing and bacteriological testing and back in service.”

This maintenance can be performed at any time of year.

The operators at Millstone are counting on both their Aquastores to withstand extreme weather conditions and continual use. The materials used in the tank’s construction make a difference in its longevity. Here is how Aquastore tanks are built:

  • A panel of high-strength, low-carbon steel is blasted and alkaline-cleaned.
  • The edges of the panel are beveled, and then it is sprayed with a stainless steel alloy.
  • The panel is sprayed with a specially formulated slurry that gives it durability, consistency and impermeability. The slurry is inorganic so it blocks corrosion.
  • The panel is then fired at temperatures above 1,500°F (815°C) to fuse the porcelain coating and the steel.
  • Tests are conducted to verify integrity and durability, including high-voltage testing to detect discontinuities.

“We prefer the Aquastore because it’s impervious to the weather and the chemicals in water,” said Joe Boyke, project manager at Clarida & Ziegler Eng., which is consulting on Millstone’s expansion.

The glass-fused-to-steel system was designed in anticipation of the wear and tear a liquid storage tank will undergo in its lifetime. By constructing a tank in a way that is resilient, CST has devised a solution that requires relatively little maintenance over time. A municipal water provider in South Dakota recently estimated that maintenance for a glass-fused to steel tank over a 60-year span would cost only $266,000.

The Results

Millstone’s Aquastore tank sports a deep blue luster that won’t fade and stands 28 ft tall and 81 ft in diameter and features an aluminum geodesic roof and cathodic protection bars on the interior. The glass-fused-to-steel panels were forged in CST’s factory in DeKalb, Ill., and shipped to the site, where they were assembled one level at a time. Scissor lifts were used to raise the dome while panels were secured underneath.

“There’s no need for scaffolding because all work can be performed from the ground and the panels fit easily together,” said Andy Rainwater, project manager at Clarida & Ziegler Eng.

Rainwater credits Cady Aquastore, the area’s exclusive CST dealer, for much of the success behind Millstone’s tanks.

“They’re always really responsive—whether it’s repair, cleanout or if we just have questions,” he said. “They’re also an essential partner when we need help with a spec or if we have specific design challenges.”

Millstone is preparing to grow, and Aquastore helps make it possible. The district sells water to nearby prisons and communities, and the boundaries of its service area will soon be extended.

“We’re rehabbing our treatment plant, and the Aquastore tanks will be the centerpiece,” said Richards. 

About the Author

CST Industries

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