SPOKANE, Wash. (AP) – Hecla Mining Co. has made a $77.4 million payment to the United States government as part of a settlement to clean up the Silver Valley of northern Idaho.

Hecla will pay an additional $42.3 million in August 2014 as part of the deal to clean up the Bunker Hill Superfund site in Kellogg, Idaho, which for decades produced silver and other metals.

"Hecla's payment marks the largest collection ever posted by the United States attorney's office in the District of Idaho," said Wendy Olson, U.S. attorney for the state, who announced the payments Tuesday.

Hecla, which is based in Coeur d'Alene, has also paid damages to the state of Idaho and to the Coeur d'Alene Indian Tribe as part of a settlement that totaled $263.4 million plus interest.

The settlement with the nation's largest silver producer was announced in June, following years of litigation.

The U.S. Environmental Protection Agency began cleanup of the Bunker Hill Superfund site in the 1980s. The mining and smelter wastes in the Silver Valley pose a threat to humans, animals and plant life. The wastes washed into rivers and streams and moved downstream to pollute Lake Coeur d'Alene and portions of the Spokane River.

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 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 was among the top 10 cash settlements in Superfund history, the EPA said.

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.

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 in the Kellogg area.