After yearslong litigation with community groups, staunch opposition from residents and recent resistance from the state environmental agency, the U.S. Army Corps of Engineers announced Tuesday it was dropping a plan to expand a toxic waste dump on the Southeast Side of Chicago.

Over the next two decades, the proposed 25-foot vertical expansion along the Lake Michigan shoreline would have taken in an additional 1 million cubic yards of contaminated sediment dredged from the Calumet River — the Corps’ solution to the disposal site’s now-full 45 acres.

“This is very good news and a victory for Chicagoans and all of us who care about protecting healthy communities and Lake Michigan,” said Howard Learner, executive director of the Environmental Law and Policy Center and lead attorney for community groups in litigation against the Army Corps.

After denying the Army Corps all of the state water quality permits needed to proceed, the Illinois Environmental Protection Agency sent a letter in January saying the proposal was contrary to some environmental regulations, including an Illinois law that prohibits the construction of new landfills or the expansion of existing landfills in Cook County.

To drop its proposal, the Army Corps withdrew its formal approval of an environmental impact statement for the project it issued in 2020, which Learner called “outdated” since it used data from 2018. The agency’s withdrawal follows a course of action the Environmental Law and Policy Center suggested to bring litigation to a “reasonable closure.”

In a news release, the Army Corps said it will work with the state, the city and the Illinois International Port District to explore “sustainable and feasible alternatives.”

The Army Corps has argued it needs somewhere to dispose of the sediment that has to be routinely dredged from the Calumet River so that commercial ships can pass through waterways connecting the Great Lakes to the Mississippi River basin.

When the Alliance of the Southeast and Friends of the Parks sued the Army Corps in 2023, the community organizations claimed that the federal agency didn’t consider alternative locations for a new dump or adequately assess the risks of expanding the current site.

In 2018, the Alliance of the Southeast rallied neighbors against the other sites — all located in the city’s 10th Ward — where the federal agency was proposing to store the toxic waste before it decided to expand the existing site.

“We are already overburdened with toxic landfills, toxic industry; we have a lot of air pollution, land pollution, water pollution. So we’ve had enough,” said Amalia NietoGomez, the alliance’s executive director. “It is our hope that the Army Corps look at sites that are outside of already overburdened communities. … This has been a hard-won fight that we’ve had, and we would not want another community to have to do the same.”

The agency’s original plan to manage dredging operations in the waterways was approved in 2020. The next year, Congress allocated funding for the vertical expansion of the disposal facility.

In the Tuesday news release, the Army Corps said it “remains committed to maintaining a safe and fully operational navigation system in Calumet Harbor and the Calumet River.”

“The Corps remains committed to maintaining commercial navigation in the Calumet Harbor, Calumet River, and the Cal-Sag Channel,” said Col. Kenneth Rockwell, commander of the Chicago District. “We will work closely with federal, state, and local partners to explore alternative solutions that balance environmental considerations, economic needs, and the long-term viability of these waterways.”

In the January Illinois EPA letter, acting Director James Jennings urged the Army Corps “to explore alternative means to manage dredged materials,” including its disposal at permitted landfills or even “upland beneficial use,” which would entail its use on dry land for habitat creation, land reclamation, soil enhancement or even construction materials.

“The ball is now in the court of the Army Corps of Engineers to come up with a better alternative, a better solution,” Learner said.

Since 1984, the Army Corps has been dumping toxic sediment dredged from the Calumet River into the containment site, which contains mercury, arsenic and polychlorinated biphenyls or PCBs. After reaching capacity or after 10 years, whichever came first, the property was to be returned to the Chicago Park District to restore as a park for the largely Black and Latino community.

Four decades later, the property hasn’t been turned over.

Gin Kilgore, interim executive director of Friends of the Parks, said in a statement Tuesday that the Army Corps did “the right thing.”

“Now we can start turning our sights to capping the existing (disposal site) and turning it into the park they deserve and was promised to residents decades ago,” she said.

Learner said the win represents not only a legal victory.

“This is an opportunity, particularly with the change in leadership at the Park District, to step up with the long-delayed, long-promised new lakefront park on the Southeast Side that will be used and enjoyed by people in the community and all Chicagoans,” Learner said. “I know I’ve said this before … the lakefront is for people and parks, not toxic waste dumps.”

adperez@chicago tribune.com