Scientists converge on Illinois to find out how ancient landscapes affect water quality – Chicago Tribune

The reversal of the Chicago River in 1900 is still celebrated as an engineering marvel, and the clean drinking water supply it helped make available in Lake Michigan spurred the explosive growth that made Chicago a world class city.

Rather than ending up near the city’s water intake cribs, Chicago’s sewage could instead be sent downstream and eventually to the Mississippi River.

It was a huge health win for Chicagoans, but communities downstream likely took a dimmer view of the engineering feat. Leaders in St. Louis reportedly asked a court to stop the river’s reversal, but by the time a judge ruled in their favor, the effluent was already on its way south via the rivers that make up the Illinois River basin.

It’s hard to say what could have been for communities such as Lockport and Joliet, which turned their backs on riverfront areas, filling them with industry.

Sewage treatment has been vastly improved in the 12 decades since, but even after processing, the waste discharge from a world class city likely continues to alter the chemistry of waterways between Chicago and the Gulf of Mexico.

It’s not the only factor contributing to a rise in “nutrients” — nitrates, phosphorus and other elements lead to increasing incidents of water quality emergencies, federal scientists said. The nutrients fuel algae populations, which then strip water of elements such as oxygen and kill off all other aquatic life.

As they figure out how to tackle the situation, the scientists enlisted a helicopter that took off from Bult Field on Tuesday in Monee, dragging underneath it a huge, somewhat trapezoidal framework adorned with certain devices.

Afterward, geophysicist Burke Minsley mentioned he’s heard lots of conspiracy theories linked to the airborne conglomeration.

He didn’t elaborate on those theories, but coming at the same time as a mysterious object floating over the country was labeled a “spy balloon,” he assured the low-flying mission on display at Bult was nothing nefarious. Minsley’s cohorts even added a whimsical smiley face to a sensor on the front end of the apparatus.

Minsley, a research geophysicist with the U.S. Geological Survey, stood before a crowd of about 30 people Tuesday at the little airport in Monee, detailing the USGS project. It involves a monthlong series of aerial sweeps by the helicopter and dangling equipment over the Illinois River basin. The project will transmit electromagnetic signals into the ground and collect the resulting data to create a rough map of underground features.

The Illinois River basin, which includes all the river’s tributaries including the Kankakee River stretching into Northwest Indiana, is one of four areas nationwide chosen for the scans. The other three basins are the Delaware River in the Mid-Atlantic region, the upper Colorado River, which famously flows through Grand Canyon National Park, and the Willamette River in Oregon.

Each river basin has unique qualities that made them worth studying, though they also are representative of others around the country, said Judith Coffman Thomas, a USGS hydrologist based in Dekalb.

“They’re basins that are important to the public and have specific water quantity and quality issues,” she said.

One of the elements making Illinois River compelling to the federal scientists is the problematic nutrients.

“We’re in our infancy in understanding how to predict these harmful algal blooms,” Coffman Thomas said. “How can we get ahead of them?”

Part of that process is figuring out the sources of the nutrients and what happens to them along the way. When scientists began to dig into that task they realized they knew very little about the interaction between water in underground aquifers and its visible counterpart in river systems such as the Illinois.

So they’re collecting what Minsley likened to “X-rays” of buried geologic structures — bedrock formations and channels where groundwater flows unseen. They’re also trying to get a better understanding of how ground water supply connects to surface flows.

Drinking water quality is a “motivating factor” for the project along with the algal blooms, though this project doesn’t address water quality directly.

Rather, “It’s more a broad regional look that will give us an understanding of how the system works,” Minsley said.

Interestingly, the scientists are less concerned about surface water contaminating underground aquifers than they are of the underground water’s effect on the surface water.

“There is reason to believe groundwater has a significant contribution to nutrients in Illinois river basin,” Coffman Thomas said.

But, she said, a better understanding of the relationship between the two water systems will also inform studies addressing emerging contaminants such as pharmaceutical residue and forever chemicals that could appear in the water supply.

“It will help us better understand how we can prepare ourselves or develop standards,” Coffman Thomas said.

Many facets of long lost landscapes buried for millennia still are affecting lives on the surface. Ancient riverbeds still contain the loose gravel and other material that allow water to move unseen underfoot. Valleys filled in by mountains of dust ground up by mile-high glaciers and blown by arctic winds across what would become the plains of Illinois still inform our aquifers.

By taking to the sky, the federal scientists are taking a closer look at just how those ancient features are impacting modern lives.

Landmarks is a weekly column by Paul Eisenberg exploring the people, places and things that have left an indelible mark on the Southland. He can be reached at peisenberg@tribpub.com.