Safely Cleaning Clarifiers: Taming A “Real Beast”

Time to clean the clarifier scum baffles, weirs and launder again. It was summer time, and algae bloomed even more fiercely than it had a month ago. Like many wastewater treatment plants, manually cleaning clarifiers at the Wolf Treatment Plant was an arduous task. Not only was it time consuming, it was difficult, and unsafe for employees.

The plant operates two 70’ clarifiers which provide a lot of surface area for algae growth.  Like many other plants, the algae growth can be especially intense in the summer months.

According to Dave Hartmann, the plant’s Chief Operator, cleaning the clarifiers was “a real beast”. To keep up with the algae, they manually cleaned the clarifier twice a week, spending roughly 4-6 hours of personnel time each week.

Workers would have to drag ladders and large, heavy fire hoses around the clarifiers, putting tremendous strain on shoulders and backs as they cleaned for hours. They were also standing above a launder with 2-3 feet of water in it.

As thick clumps of algae broke free, they were sent downstream, essentially transferring the cleaning issue to the next process and not providing a solution.

The staff was determined to make the plant a safer place to operate and they began to investigate solutions. After looking at brushes and some other methods of cleaning, Hartmann spoke to Kevin Freber, a Water Systems Manager, about an automated cleaning system that he had helped implement at the City of Watertown. A short field trip to see it in action made him realize this solution made a lot of sense.

The solution was a Weir Washer^TM automated cleaning system. It uses non-potable plant water to remove algae and other debris from the surface on the clarifier components. (See how another wastewater treatment plant employed the same solution, How A Wastewater Superintendent Made His Clarifier Safer, Run Better.)

Hartmann called Crane Engineering to order and install the Weir Washer system. It took less than two days to install on the two 70’ clarifiers, and they were able to do it themselves.

Hartmann claims that the Weir Washer systems have not only helped make the plant a safer place to work, but they’ve also helped their plant achieve more consistent operation and reduce maintenance. “There’s no good, safe, manual way to clean a clarifier. If you’re looking to keep operators safe, this is a tool that can eliminate the stress and strain involved,” said Hartmann.

Want to eliminate cleaning clarifier weirs from your to-do list? Ask us about it! We gladly provide technical assistance to municipalities in Wisconsin and upper Michigan.