Nutrient rich soil on the bottom of the Fox River and Chain O' Lakes feeds oxygen-choking algae and hinders boaters, but it could become a valuable commodity for the Fox Waterway Agency.
With $350,000 from the Illinois Department of Natural Resources' Mud to Parks program, the agency has begun building two huge earthen bowls that will be used to store up to 130,000 cubic yards of dredged sediment.
The material, mostly topsoil that erodes from farm fields and other areas in Wisconsin, will be dried and sold to municipalities, landscapers and other big users for $12 a cubic yard.
"It's a completely natural process," said Ingrid Danler, the agency's executive director. "It's like letting a glass of muddy water sit for awhile."
The scale of the project is huge, as a typical dump truck holds about 8 to 10 cubic yards of material. And at a total cost of $880,000, it represents a big investment the agency thinks will pay off by allowing it to clear more waterways and use the dredged material as a source of revenue.
"This project was actually something we've been pitching to our state legislators for about three years now," Danler said.
The Fox Waterway Agency is a regional government body that involves multiple federal and state jurisdictions and works with a bipartisan group of area legislators in Lake and McHenry counties.
The remaining funding for the project comes from the capital development fund of the Office of Water Resources, which is within IDNR.
The bowls are being built at Cooper Farms, which covers 23 acres between Grass Lake and Lake Marie and is managed by Chain O' Lakes State Park. The "dewatering" areas will be more than 3 acres each. There also will be a sediment recovery and recycling area.
Neither residents nor boaters will be able to see the operation, but it will allow the agency to expand dredging in the Lake Marie and Grass Lake areas and the heavily used channel that connects them.
That becomes important because 50,000 cubic yards of sediment flows into the agency's jurisdiction each year, but there isn't enough room to store it all.
"With these two cells, we can get ahead of the game. It keeps coming,["] said Wayne Blake, the agency's chairman.
There are three methods of dredging, but in this area, the agency would use a hydraulic method essentially vacuuming the sediment from the lake bottoms and pumping it through adjustable lengths of floating pipe.
With the new storage facilities, the agency will be able to do more dredging and make the waterways easier to navigate.
"We will be able to make a huge dent where we couldn't before," Danler said.
In the past, the agency paid $200,000 or more each year to have dredged material hauled away. A few years ago, a depository for the nitrogen and phosphorous rich soil was established on Ackerman Island near Fox Lake in an area about a fifth of the size of the size of Cooper Farms.
Since it opened, about 20,000 cubic yards of soil has been given away to municipalities and other entities in the area.
"We've also put the material on two farm fields, organic farmers, up in the Richmond area. The yields are amazing," Danler said.
Blake said the sediment is considered state property and, until a recent change in legislation, could not be sold. Topsoil now can be sold to businesses and individuals for use in a variety of projects.
Blake said the commodity is valuable to contractors, developers, road buildings and others.
"There has been quite a bit of interest, actually. Once the word got out, the phones started ringing. Even the city of Chicago was looking at it," he said.
Proceeds from the sale of the dried sediment will allow the agency to fund other projects, according to Danler.
"We wanted to make sure there was a market for the material," she said.
Cooper Farms will be a first for soil recycling in the area and is part of the agency's "Navigating the Future" campaign to improve the navigability and water quality of the lakes.
The Mud to Parks program was first used in 2003 to take Illinois River sediment from Peoria Lake to develop a new park in Chicago.