SAGINAW, MICH. — Every spring, Dow Chemical sponsors a fishing tournament "celebrating all things walleye" on the river that flows past its sprawling world headquarters.
Signs warn anglers not to eat the fish, which are contaminated with cancer-causing dioxins that the company dumped into the Tittabawassee River for most of the last century. Yet tournament organizers sell hats featuring the slogan "Dioxins My Ass."
Such conflicting messages are common in this picturesque and economically distressed region, where Dow is a major employer but is also responsible for poisoning a vast river valley that stretches more than 50 miles into the Saginaw Bay and Lake Huron.
Now, after three decades of promises by federal and state officials to force Dow to clean up the mess, the Obama administration is stepping in with a new plan intended to scour away decades of contamination that turned this area into one of the nation's most polluted sites.
Last month, the U.S. Environmental Protection Agency and Dow announced a deal they contend will finally address dioxin contamination from the company's chemical complex in nearby Midland, about 200 miles northeast of Chicago.
The success -- or failure -- of what happens here could affect dozens of other heavily polluted sites along the Great Lakes. The Saginaw Bay is one of 31 "areas of concern" on the U.S. side of the lakes that wash toxic chemicals into the world's largest source of fresh surface water.
Under provisions in the federal Superfund law, Dow will be required to evaluate and clean up dioxin-contaminated land along the Tittabawassee and Saginaw rivers starting this winter. Dow also agreed to work downstream from its plant to remove or cap dioxin-contaminated sediment, preventing toxic muck from churning back into the water and spreading farther into the Saginaw Bay. The goal is to restore the watershed by 2018.
"We are on the right track now," said Robert Sussman, senior policy advisor to EPA Administrator Lisa Jackson. "Once the work begins, we will have the momentum to get this done."
Given the sluggish pace of previous cleanup work, the EPA's inspector general recently had concluded the sites wouldn't be restored until 2086. The Obama administration has promised to set aside more money to speed things up and is pushing to restore a tax on polluters to help cover the tab, estimated to reach $4.5 billion.
Dioxins, a family of compounds that were manufacturing byproducts of the Vietnam-era herbicide Agent Orange and other chlorinated chemicals, are so toxic they are measured in trillionths of a gram. The most potent, known as 2,3,7,8-TCDD, was responsible for two of the nation's most infamous environmental disasters, leading to the evacuations of the Love Canal neighborhood in upstate New York and the entire town of Times Beach, Mo.
In the Saginaw area, Dow has fiercely resisted federal and state cleanup efforts and insisted the pollution doesn't threaten people or wildlife.
Company records show Dow has known since at least the mid-1960s that dioxins could sicken or even kill people. Based on independent studies, the EPA says the chemicals can cause cancer and disrupt the immune and reproductive systems, even at very low levels. The agency says there is no safe level of exposure.
Critics, including the EPA, have accused Dow of repeatedly delaying action and misleading the public about the dangers of dioxins. The company insists the contamination does not pose health risks but hailed its deal with the EPA anyway.
"We are committed -- in both our words and our actions -- to moving forward . . . to resolve the issue," Dow spokeswoman Mary Draves said in an e-mail response to questions.
One small sign of the company's commitment: Dow recently agreed to follow through on a 2004 legal agreement with Michigan officials to pay for more dioxin warnings along the contaminated rivers. The additional signs should be up by next spring -- in time for the annual walleye tournament on the Tittabawassee.
As for the watershed restoration, critics remain wary.
"This cleanup can get done, and a company like Dow can afford it," said Tracey Easthope of the Ecology Center, a Michigan environmental group. "But we are under no illusions that this will be carried out without constant pressure from concerned citizens."