You've seen them - even if you don't have an immediate idea of what they do. The tall, white "domes" that reside alongside of I-35 in Duluth, on the Western Lake Superior Sanitary District's campus.

They're clarifiers and the hold and process millions of gallons of wastewater at the treatment facility.  Inside, the suspended solids contained in the wastewater is left to let gravity do the work of separating it from the liquid. It's all part of the process that the water received before its discharged - eventually, and after other processing - into the St. Louis River.

Recently, one of the larger clarifier units failed.  That failure led to the unit being taken offline, leavin WLSSD with only three remaining clarifiers to do the work. For the time being, that isn't a critical problem - at least according to WLSSD Executive Director Marianne Bohren.  The facility can get by "quite well with just three, except during period of heavy rain".

But Duluth does get heavy rain - and even if it didn't, WLSSD's capacity would be capped at a lesser amount than it was designed for.  In order to investigate the cause and solidify a fix, the WLSSD Board recently approved $3 million from reserve funds to facilitate the work.

But even as the cause of the failure of the clarifier - and it's eventual fix - is being worked on, WLSSD officials anticipate that what's happened to this particular unit could (will) eventually happen to the other three.  This is due to the similar age and composition.

That's why the WLSSD is seeking "an increased request in the 2022 legislative session to cover half of the funding necessary to renovate all four clarifiers".  The new request comes as an earlier request for $6.95 million in state bonding support to overhaul" the units failed.  That request occured before this most-recent failure.  Since that time, the need has become more apparent.

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