DULUTH — A project that marks the final stretch in a decades-long effort to cleanse a century of pollution from the St. Louis River received a major boost this week.

The Environmental Protection Agency (EPA) announced more than $22 million to remove contaminated sediment in the river's Thomson Reservoir in Carlton, Minn. The money makes up a large portion of the $36 million project, with the Minnesota Pollution Control Agency and PotlatchDeltic, a forest products company that once operated a paper mill in Cloquet, paying the remainder.

The funding "marks a crucial step toward the delisting of the St. Louis River Area of Concern, and ultimately its restoration as a healthy ecosystem," EPA Great Lakes National Program Office Director Teresa Seidel said in a news release.

Federal bipartisan infrastructure money will help pay for cleanup at the 330-acre Thomson Reservoir, constructed in 1908. The water is polluted by long-ago unregulated discharge from paper, matchstick, toothpick and building material manufacturing, along with sewage.

The federal and state environmental agencies, along with PotlatchDeltic, will work together to apply a layer of activated carbon pellets over 225,000 cubic yards of contaminated sediment. The pellets bind to contaminants, preventing accumulation in bottom-dwelling organisms to protect aquatic life.

The reservoir project signals the final agreement between the state pollution control agency and the EPA to finish remediation work in the St. Louis River on the Minnesota side, the EPA said. A few more projects remain on the Wisconsin side.

The largest of the river's remediation projects is the U.S. Steel Superfund site, paid for by the EPA and U.S. Steel. It will reopen next summer as permanently protected green space with a 2-mile trail extension along the water, a 1-mile wheelchair-accessible loop circling a peninsula, bridges and interpretive signs honoring the Anishinaabe's ties with the river.

The EPA has said cleanup and restoration work of the river should be finished by 2030, if not sooner. Work on the reservoir will begin this summer.