Crane's Fluid Connection Blog | Fluid Handling Tips

Aging Wastewater Clarifier? What To Do About It

Written by Sara Peters | November 25, 2014

When a Michigan wastewater treatment plant noticed their clarifier's skimmer arms were scraping the bottom of the tank, they knew something was wrong. But what they didn't realize was how wrong things had become. By the time Crane's technical resources were called in, not only were the races in the drive turntable completely worn away, but the entire lower housing was worn so badly it was beyond repair, costing the facility an additional $23,000 for replacement.

In Wisconsin, another facility blew its budget away by an additional $240,000 because nearly half the steel in the clarifier was deteriorated and needed to be replaced. 

Good things don't always come to those who wait. Waiting to repair or rehabilitate wastewater clarifiers for too long can mean big repair costs. It's important to watch for the warning signs (failing paint, exposed metal, skimmer arms running out of plane, changes in oil) indicating trouble up ahead. 

If you've noticed one of the warning signs, there are a couple of options you can consider for repair:

1. FUNCTIONAL REPAIR
Sometimes budget restraints prohibit a complete clarifier overhaul. Other times, there are pieces that need repair now, while some components, such as a drive, may still have more life left before it needs repair. 

In these cases, repairs can be made to keep the clarifier operational. There is some risk to this however, operating like new components with worn components can cause the repaired components to wear faster. 

When the entire clarifier is in need of repair, we do not recommend only fixing one piece at a time. It will end up costing you more in the end. 

2. WASTEWATER CLARIFIER REHABILITATION

If the clarifier needs a complete overhaul, a clarifier rehab is probably the way to go. This restores the clarifier to "like new" condition. A service like this typically includes (but is not limited to):

  • Blasting and coating of all ferrous metal surfaces (bridge, walkways, sludge collection mechanisms)
  • Replacement of damaged metal
  • Rebuilding of clarifier drive mechanism
  • Replacement of weirs and baffles
  • Reconditioning of concrete surfaces
  • Replacement of squeeges and plows
  • Refurbishment of beach

The effects of this service are long lasting, typically 20+ years.

Whether you decide to go with the functional repairs to keep operating in the short term, or a clarifier rehabilitation as a long term solution, when warning signs are evident, take action as soon as possible. The cost of clarifier repair increases the longer it is left to its own devices.

Is your clarifier showing the warning signs? Request a complimentary clarifier consultation. We gladly provide technical assistance to businesses and municipalities in Wisconsin and Upper Michigan.