Countdown to Earth Day: Phosphorus Is One of Fox River's Biggest Threats

Countdown to Earth Day: Phosphorus Is One of Fox River’s Biggest Threats


  • This month, Kane County Connects will highlight the organizations that are working to conserve and protect our local environment. Check out this “Countdown to Earth Day” feature every day from now until April 22 to learn more about the people and projects that are helping to improve sustainability throughout the Fox Valley. Today’s article comes to us from the Fox River Study Group.

A high level of phosphorus — caused by wastewater treatment plant discharge and runoff from fertilizers used for agriculture and to green up suburban lawns and gardens — is one of the chief problems facing the ecology of the Fox River.

What are we doing to solve that problem?

For the past 14 years, representatives from counties, cities, villages, wastewater agencies and watershed groups have teamed up to study and improve the quality of the Fox River under the umbrella of the nonprofit organization, the Fox River Study Group. The group has conducted extensive monitoring of the river and developed computer models to help make decisions about how best to resolve the river’s challenges.

Screen Shot 2016-04-14 at 1.38.04 PMJust this past December, the Fox River Implementation Plan — “the FRIP” — was finalized. This report outlines steps to be taken to address the problems caused by high levels of phosphorus in the river.

The Problem: Phosphorus, Algae and Dams

Phosphorus enters the river in wastewater treatment plant discharges and in runoff from urban and agricultural areas. Too much phosphorus causes excess algae and plant overgrowth in the Fox. This overgrowth consumes the oxygen in the water and causes it to drop below levels considered safe for fish, mussels and other aquatic life. Algae-laden water also creates taste and odor problems for the 300,000 people in Elgin and Aurora who receive their drinking water from the Fox River.


The problem with algae overgrowth is heightened on the Fox River because its many dams make the river behave more like a lake than a river. Dam pools provide an ideal environment for algae to thrive. The FRIP calls for a number of short-term actions and continued study of how phosphorus reductions and dam removal could improve water quality.

The Solution: Tracking, Regulation and Plant Improvements

Municipal wastewater plants — which discharge more than a million gallons of treated water per day — are making plant improvements that will cut their phosphorus loads by at least two-thirds. Some plants, such as Algonquin’s, have had this technology in place since 2012. By 2021, all major plants on the Fox River will have added basic phosphorus removal technologies.

“Removing phosphorus at the wastewater treatment plants is a huge first step,” said Rob Linke, a water resources engineer with the Kane County Division of Environmental & Water Resources and also the county’s representative on the Fox River Study Group Board of Directors. “However, there are other sources of phosphorus that wash off into our rivers and streams that need to be addressed, too.”

Phosphorus and algae also enter the Fox River from the Chain O’Lakes region upstream. Illinois EPA will complete a plan on how to reduce phosphorus in the chain to very low levels by the end of this year.

Farmers and municipalities are being asked to track phosphorus reductions in runoff when they implement best management practices to prevent fertilizer loss from farm fields and to clean up urban stormwater. The Army Corps of Engineers is studying options for dams on the Fox River to improve habitat and fish passage, and the Forest Preserve District of Kane County and North Aurora are working on removal plans for the Carpentersville and North Aurora dams, respectively.

The FRIP will be updated as these actions are taken and as the study group measures how the river responds through ongoing water quality monitoring. This is a group effort to sustain the centerpiece of the Fox Valley for generations to come.

Dams on Fox