Washing the Wastewater

a fascinating trip into the world of local sewage

Emily Kuhn, illustrated by Beth Czech, photos by Andrea Paulseth

JUST CONTEMPLATING LIFE AT THE OL’ SEWAGE PLANT. Last year, the City of Eau Claire’s Wastewater Treatment Plant treated 2.06 million gallons of your, um, used water.

What is the first thing you do when you get up in the morning? How about the last thing you do before going to bed at night? “Using the facilities,” or whatever phrase you prefer, is an act that everyone does, but not too many think about. In fact, I think it’s fair to say that most people take that ability for granted. Well, after taking an in-depth tour of Eau Claire’s Wastewater Treatment Plant, I can promise you that I’ll never use the ladies’ room without first thanking the City of Eau Claire!

Responsible for treating 7.3 million gallons of wastewater daily, the plant operates 24 hours a day, seven days a week, just to keep Eau Claire residents’ toilets working … that is, they ensure that whatever is flushed does not re-appear as a flooded, smelly mess at 2 a.m. when you’re trying to sleep. In fact, about 25,000 residential and commercial customers rest easy, thanks to the plant’s careful monitoring of over 320 miles of sewer pipelines.

“There’s so much going on that people have no concept of,” stated plant supervisor Craig Hendrickson, who, in the early morning hours the day of this interview, responded to call about a grease-clogged sewer pipe that was blocking the flow of wastewater. “(This job) is one of the most interesting entities of the city. Even though it’s ‘yucky,’ we have the ability to take a product that’s pretty messy and put it back into the environment in a very clean state.”

Indeed, when the plant is not busy responding to sewer emergencies like back-ups and clogs – in addition to, of course, a regularly scheduled pipe maintenance system – the plant ensures that every drop of the 2.06 million gallons of wastewater it treats each year leaves the plant as clean as possible. Specifically, the plant’s lab carefully tests both the biochemical oxygen demand (the “strength” of the sewage coming in) and the total suspended solid levels (the amount of suspended organic waste) of all incoming water. By regulating these two aspects, the plant ensures their effluent matter meets specific restrictions put in place by Wisconsin’s Department of Natural Resources. For instance, wastewater entering the facility might contain 300 parts per million of organic waste materials, but it will leave with only 15 parts per million.