The largest mining company in Idaho's Silver Valley will pay $263.4 million plus interest to settle one of the nation's largest Superfund lawsuits — one of the top 10 such settlements in history, the U.S. Environmental Protection Agency said Monday.

The U.S. Department of Justice on Monday announced that Hecla Mining Co., of Coeur d'Alene, Idaho, will pay the money to the United States, the state of Idaho and Coeur d'Alene tribal governments for releasing mining wastes into the environment during decades of silver production

"We are really pleased with this settlement because it helps us get certainty and hopefully begin a new era moving forward in the valley," Dennis McLerran, EPA regional director in Seattle said.

The settlement was filed Monday in federal court in Boise, Idaho. Hecla was the last major defendant remaining in a huge Superfund lawsuit filed in 1991.

Of the money, 75 percent will go to the EPA for cleanup work. The remaining 25 percent will go to federal, state and tribal entities to help repair the environment and restore wildlife in the valley, the EPA said.

Hecla is the nation's largest silver producer, operating the Lucky Friday Mine in the Silver Valley and a mine in Mexico.

The company said it would not comment on the settlement until after trading had closed on the New York Stock Exchange on Monday.

The lawsuit was originally brought in 1991 against Hecla and other mining companies in the Silver Valley by the Coeur d'Alene Tribe, seeking penalties for damage to water, fish and birds caused by millions of tons of mining wastes that were released for decades into the South Fork of the Coeur d'Alene River and its tributaries.

The EPA has been performing cleanup work in the Coeur d'Alene River Basin since the early 1980's, and the lawsuit also sought to recover cleanup costs.

The governments have already reached settlements with other mining companies that had historic operations in valley, which is 50 miles east of Spokane, Wash. That included ASARCO, which along with Hecla was a primary defendant. ASARCO reached a settlement in 2008 to pay nearly $500 million toward cleanup.

Like the ASARCO settlement, the Hecla deal is among the top 10 cash settlements in Superfund history, the EPA said.

"This agreement will help pay for the U.S. government's cleanup activities, secures natural resource damages, and will restore critical habitats to fish and wildlife in the Coeur d'Alene River Basin," said Ignacia S. Moreno, assistant attorney general for the environment at the Justice Department.

The Bunker Hill Superfund site is one of the nation's largest and most contaminated, with widespread releases of toxic metals such as lead and arsenic that have sickened residents for decades. Despite years of cleanup, much contamination remains.

"This settlement brings decades of litigation to a close and provides a clear path to continue restoring the health of the environment, economy and communities of the Coeur d'Alene Basin," Idaho Governor C.L. "Butch" Otter said.

The consent decree is subject to a 30-day public comment period and approval by the federal court.

Under the deal, Hecla has agreed to pay $102 million in cash and $55.5 million in cash or stock 30 days after entry of the consent decree. The company would pay an additional $25 million in cash 30 days after the first anniversary of the decree, $15 million in cash 30 days after the second anniversary, and $65.9 million by August 2014.

Before the EPA cleanup began, the Silver Valley was so saturated with pollution that it stripped the hillsides of vegetation and poisoned the blood of children, causing physical and emotional problems that continue to this day.

The EPA has spent nearly 20 years removing lead from the environment here, and claims great success because the average blood lead level of children has dropped to about normal, which is 2 micrograms per deciliter of blood. Critics scoff at those results, because only a handful of children are being tested.

Cleanup efforts have centered on public health, including replacing soil in about 5,800 residential yards.

Meanwhile, Hecla Mining continues work to expand its Lucky Friday Mine. The company is spending $200 million to increase silver production by about 60 percent and extend the mine life beyond 2030. A worker died at the mine after a roof caved in earlier this year.