Department of
Environmental Quality

The region between Mullan and Cataldo in northern Idaho, called the Silver Valley, was founded over 100 years ago for its rich lead, zinc and silver mining opportunities. In the early years, mining and milling methods were inefficient compared to today and resulted in resource minerals and other concentrated constituents (lead, zinc, silver, cadmium and arsenic) remaining in the tailings. Remaining minerals and chemicals used in the milling process are hazardous to humans, fish, and waterfowl. Today, operating mines function at a higher efficiency for extraction and milling processes and operate under both state and federal environmental laws.

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Nature of the Cleanup

At one time, the method of getting rid of mine wastes was to discharge them into the river. Even when not discharged into the river, uncontrolled tailings and other mine wastes were subject to erosion and oftentimes washed away from the work site into the South Fork of the Coeur d’Alene River and its tributary streams leading to Coeur d’Alene Lake. The South Fork’s floodplain in Cataldo not only deposited metal-laden mine wastes on the valley floor, but the “Cataldo Flats” were a popular dumping ground for mill leftovers. Additionally, early-day smelting operations were not subject to air pollution control like they are today. The release of metals and chemicals into the atmosphere was toxic.

Extent of the Cleanup

The cleanup area in the Basin is any place where mining-related contaminants have come to be present. The cleanup is divided into three areas — Operable Units 1, 2, and 3 — which encompass populated and non-populated areas of the Bunker Hill Box and areas in the South Fork and main Coeur d'Alene River watersheds. Learn more.

Records of Decision

A Record of Decision (ROD) is a legal public document issued by EPA outlining the cleanup plan that will be used to clean up a Superfund site. EPA is the lead agency for the Bunker Hill Superfund Site and has issued three RODs for the Site. The RODs generally correspond with the land area in which remedies are addressed called Operable Units (OUs). Learn more.

Basin Property Remediation Program

The Basin Property Remediation Program (BPRP), administered by DEQ,  removes contaminated soil from properties in places where humans are frequently exposed, such as yards, parks, and public properties. Cleanup also includes rehabilitation of mine and mill sites, railroad rights of way, places where people recreate, and where the site affects drinking water or fisheries. Learn more.

Idaho's Role in the Cleanup

DEQ is a "consulting party" to EPA for cleanup actions. DEQ helps shape the scope of work and the approach for implementation of the cleanup, taking into consideration local interests, local concerns, and the state’s goals and priorities. Learn more.

Soil Repositories

Soil repositories keep the public safe by locating contaminated material in a central, stabilized, controlled location which is regularly monitored to ensure public and ecological safety. Learn more.

• Page Waste Repository
• East Mission Flats Repository