Thursday, October 18, 2012

UCSD open house gives public view of essential processes

UCSD open house gives public view of essential processes

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If you invited friends or family to join you for an open house at a wastewater treatment plant, would they laugh? I’m not naming any names, but I was on my own when I set out for the recent open house at the Urbana-Champaign Sanitary District’s facility on East University Avenue. 

To my delight, however, plenty of other local residents were curious enough about the plant come out for a look around. According to the estimate of UCSD executive director Rick Manner, approximately 200 people stopped by over the course of the day—enough to make him consider holding the event annually.

Manner and his staff were motivated to host an open house because they wanted the people who are served by the plant to see what was accomplished in its just-completed, two-year renovation. Updates to the plant included new buildings to accommodate some of the treatment processes that take place there, as well as new space to accommodate employees as well.

[Photos by author: primary clarifier; control room; water sample; at the outfall.]

Of course, since most visitors to the plant came knowing little of the processes used to treat wastewater, the highlight of the open house was a guided tour that allowed us to see them firsthand.

I was fortunate to fall in with a group that included a Champaign father who had brought along his two young daughters and a friend of theirs. At the outset of our tour, the girls were quick to say they had come only because they hadn’t been given a choice. But their tune soon changed, and their lively interest made the afternoon more enjoyable for everyone involved.

Our tour was led by Dave Hermes, whose regular role is supervisor of maintenance at the plant. He provided concise explanations of what we were seeing at each stop, and answered our questions with the patience of a theme-park tour guide.
We started at the building where sewage entering the plant undergoes an initial screening to remove paper and grit. The material taken out in this process is the only byproduct of the plant that goes to a landfill, and the quantity of it is surprisingly small, on the order of a Dumpster or two a week.

We then proceeded through the plant in the same order that wastewater does: to the enormous, circular open-air tanks set deep in the ground where primary clarification takes place; to the concrete weirs where the wastewater churns with bacteria and other microorganisms in a process called “activated sludge”; to secondary clarifiers; to the tallest structures at the plant, nitrification towers, where the water runs down through stacked layers of honeycomb-like plastic, and toxic ammonia is converted to nontoxic nitrates by the action of another group of microorganisms; and finally to the building where water runs through a fabric filter; and back outdoors, where a chlorine-based disinfectant renders the effluent of the plant fit for human contact and capable of supporting aquatic life.

At each stop, a tightly sealed jar of the water from that stage was available for close inspection.

Our tour ended where the discharge from the plant pours into the Saline Branch, one of the most significant tributaries to the Salt Fork of the Vermilion River. As our group dispersed, I overheard the father of the young girls ask for reactions to the tour. “It was more interesting than I thought it would be,” allowed one. “Definitely not boring,” added the other.

One measure of how well the UCSD’s northeast treatment plant does its job is the diversity of aquatic life that thrives downstream from it. Executive director Manner called my attention to the discovery this year of a fish called the big-eyed chub in the Saline Branch. It’s a species that hasn’t been found in Champaign County since 1899.

Tune in next week for a story about the fish survey that prompted that phone call.