Workers from the Environmental Protection Agency respond to an oil spill Oct. 26 at a fork of the Chicago River known as Bubbly Creek. (EPA)

The EPA likely won’t be able to determine the source of a late October oil spill in the Chicago River because the agency was notified about the spill two days after it occurred, the EPA said Tuesday. 

Geoffrey Baer gets ready for a new voyage along the Chicago River with viewer questions about the history of our city’s favorite Y-shaped waterway.

Workers from the Environmental Protection Agency respond to an oil spill that was reported Oct. 26 at a fork of the Chicago River known as Bubbly Creek. (EPA)

Officials responding to last week’s oil spill in the South Branch of the Chicago River have recovered dead wildlife from the water, including 43 fish and four turtles. The source of the spill is still unknown, according to the EPA. 

Workers from the Environmental Protection Agency respond to an oil spill Oct. 26 at a fork of the Chicago River known as Bubbly Creek. (EPA)

The EPA says the source of an Oct. 26 oil spill remains unknown, but cleanup efforts continue this week along the 1.5-mile stretch of the south fork of the South Branch of the Chicago River.

Flooding in Albany Park in April 2013 (Center for Neighborhood Technology / Flickr)

There are more soggy days ahead. Find out how you can help ease the burden on the Chicago River and reduce the risk of flooding.

Hundreds of anglers participate in the #ChicagoFishes event Oct. 13 to celebrate decades of cleanup efforts to the Chicago River. (© Shedd Aquarium)

An American eel caught by a 5-year-old angler last week is possibly the first such eel ever recorded in the Chicago River, according to the Illinois Department of Natural Resources.

A duck found dead in the Chicago River. (Courtesy of Friends of the Chicago River)

Dozens of mallards have been found dead over the past month in multiple locations along the Chicago River, marking what one expert says is the largest occurrence of birds dying in the river in decades.

There’s a new floating attraction along Chicago’s Riverwalk. We go for a look.

(Smart Destinations / Flickr)

As more cruises and kayaks join commercial barges on the river, some tour boat operators are concerned about safety. Learn the “rules of the road” for Chicago waterways.

A. Finkl & Sons Co. (Noah Vaughn / Flickr)

Plans for new office buildings, apartment complexes and hotels along the North Branch of the Chicago River are underway.

The Chicago River is a lot cleaner than it used to be. And after years of litigation, the Metropolitan Water Reclamation District and environmental groups have agreed to a settlement and will work together to make the river even cleaner. 

The decadeslong fight to clean up the Chicago River took a step forward last week with the resolution of two lawsuits targeting phosphorous discharge that has polluted waters from Chicago to the Gulf of Mexico.

(Roman Boed / Flickr)

Geoffrey Baer dives into the history of Chicago’s water and answers viewer questions about ghostly paper images haunting a South Side neighborhood and memories of a space-themed park.

Mayor Rahm Emanuel leads a tour of a new section of the Chicago Riverwalk, which will be open to the public Saturday. (Courtesy City of Chicago)

The completion of the three-block stretch marks the end of construction on the 1.25-mile promenade, providing pedestrian and bike access along the south bank of the river.

A bighead carp (U.S. Geological Survey / Flickr). Inset: An Asian carp burger at Asian Carp Grill 2015. (Margaret Frisbie)

Adventurous eaters concerned about Asian carp entering the Great Lakes will have a chance to devour the invasive fish at a special event held along the Chicago River next week.

(Metropolitan Water Reclamation District)

The notoriously polluted Chicago River is about to get cleaner with disinfection technology at a Skokie water treatment facility.