DeKalb Sewage Plant In Final Stages Of $46.3 Million Upgrade
TheKishwaukee Water Reclamation District is responsible for cleaning local sewage in DeKalb and at Northern Illinois University. A more than $45 million project aims to modernize the plant.
The District’s first wastewater treatment plant was built in 1928 and many of its older buildings are still in use. This hasn’t hurt the plant’s ability to clean sewer water. But District Assistant Engineering Manager Mike Holland says the plant still needs to move forward. And that’s why it launched the improvement projecttwo years ago.
Holland said, “We are upgrading technology that we’ve been using for 80 years and just can’t meet environmental regulations anymore."
A key regulation is the ability to filter out certain pollutants. The District upgraded the plant to handle ammonia, but without new equipment, it couldn’t effectively remove phosphorus. This will be necessary for the plant's new discharge permit under the Illinois EPA. Filtering these substances helps stop the formation of oxygen-poor zones and algae blooms.
Another big change is making the current treatment process more energy efficient. The plant uses bacteria to break down solid wastes into a product that can be spread on farm fields. Holland says the bacteria then releases a “biogas.”
"We currently use our biogas for heating in our digesters, but since it’s a combustible gas, if you can clean it up more and get it to be more pure methane, then you can run a generator off of it," he said.
But District Manager Mark Eddington says sewage waste alone won’t power the plant.
“We supplement by taking hauled waste from a lot of different food processes, restaurant grease, and that really provides a great amount of gas,” said Eddington.
With the cleaning equipment, the plant can use the methane to run most of its processes off a 375 kilowatt generator on a normal day. If something like a heavy storm requires the plant to turn on more pumps, the generator will simply reduce how much energy is needed from the grid.
Holland says this isn’t the only opportunity for energy savings.
“We’ve got some areas within our plant, the tankage that we can’t reuse, that we are thinking could be a great spot for us to fill in and put in solar panels at some point in the future,” he said.
Other vacant land will be given back to neighboring Hopkins Park for use by the public. Some has already become an official waystation for Monarch butterflies.
And then there’s optimization. Much of the bacteria used to eat organic waste does its job in outdoor tanks. The microbes are sensitive to temperature, and slow down their digestion in the winter months. Replacing these tanks will be indoor basins. Here, plant staff can more precisely control the temperature and oxygen levels of the water that's filtered by the bacteria.
And then there are "quality-of-life" improvements. Holland says the District now has a brand new main building and lab. It replaces a well worn facility that once had a more nauseating function.
“It was an old sludge incinerator building, so we took a building that used to literally burn poo and put some drywall up and made it into a lab and a home for our operators," he said.
This project hasn’t been without growing pains, however. Much of the new technology relies on more modern computer infrastructure. Eddington says that means more staff training.
“So you’re trying to teach 40 years’ worth of age how to get up to snuff on lot of technical IT-related equipment," he said.
There’s also the possibility of pricier water bills. The district aims to keep rate increases down to cost of living increases of about 1-2%. Eddington says they’re also reaching out to another community in the district’s service area, Malta. The District can then make arrangements to filter their sewage.
“The more folks we can serve, the more we can spread out those capital costs across a larger user base," he said.
At this point, the construction is 80 to 90% complete. But Eddington says the grand opening of the new facility is still about a year away.
“The devil’s in the details. So that’s when electronics and control systems and those sorts of things are really brought up to code," he said.
The changes mean a lot to the plant, but Eddington says, ideally, it should be "business as usual" for the average resident.
"They’ll continue to flush, we’ll continue to treat the water, and good Lord willing, it’ll keep going that way,” he said.