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The Bunker Hill Superfund Site spans northern Idaho and eastern Washington in an area known as the Silver Valley. Mining and milling operations started in the mid to early 1880s, which resulted in heavy metal contamination throughout the area.

Lead and other heavy metals can pose a risk to people’s health particularly to young children and pregnant women. As a result of this human health concern, the US Environmental Protection Agency (EPA) added this site to the National Priorities List in 1983. Although cleanup efforts have reduced exposures to susceptible populations over the last 30 years, the nature of the cleanup requires ongoing local oversight to ensure completed remedies are protected and additional cleanup activities continue as communities grow and land use changes.


Bunker Hill Baghouse Fire

September 3, 2023 marks the 50th Anniversary of a pivotal moment in the history of the Bunker Hill Mining & Metallurgical Complex Superfund Site still impacting the Silver Valley in Northern Idaho today. Below is a high-level timeline of the decisions and events leading up to and after the baghouse fire. This is a complex history and we hope you will return as we build on this timeline as a resource for all; today and for future generations to come.



Clean Air Act Established

The first federal legislation regarding air pollution control.

Photo Credit:  Marc Wieland on Unsplash


Air Quality Act

Expands Federal Government activities pertaining to air pollution control.


Photo Credit: Clean Air Act (United States). (2023, August 12). In Wikipedia.



Gulf Resources & Chemical Corp. Acquires Bunker Hill.

As part of their acquisition, they decide to begin modifications to the smelter that will allow them to process more ore to compete in global trade. These upgrades increased the capacity of the sinter (crushing and roasting of ore) and blast furnace (making of lead). 

Photo Credit: Bunker Hill Mine and Smelting Complex. (2023, August 7). In Wikipedia.


Clean Air Amendments and EPA Regulatory Pressure

Amendments establish procedures under which the EPA sets national standards for ambient air quality:

  • In order to meet these standards, Bunker Hill needs to fix leaks and install new bag filters to capture twice as many particulates in order to reduce their lead emissions by half.

  • Bunker Hill is set up on a plan from the EPA to complete needed upgrades by 1975.


Photo Credit: Clean Air Act (United States). (2023, August 12). In Wikipedia.

On March 29, the EPA informs Bunker Hill ​ it will impose air pollution control standards on their lead and zinc operations in Kellogg, ID.

On April 3, a $100,000 campaign contribution from a Gulf Resources & Chemical Corp. bank account is made to Nixon's re-election campaign, the committee of which Gulf Resources CEO is a member of.  Click here to read Woodward and Bernstein's 1972 news article covering this as part of their Pulitzer Prize-winning coverage of the Watergate investigation.



Nixon issues Executive Order 11615

Executive Order 11615 imposes a 90-day freeze on all prices and wages throughout the U.S. in an effort to counter inflation. 

Photo Credit: White House Photo Office Collection, 01/20/1969 - 08/09/1974; Nixon Presidential Materials Staff, College Park, MD.


Bunker Hill Public Dissent

Frank G. Woodruff, President of Bunker Hill, states in a public hearing that, "The EPA regulation is ill-conceived, currently unattainable and unnecessarily restrictive."


Photo Credit: Michigan Tech University.


Photo Credit: Richard Nixon. (2023, August 11). In Wikipedia.


Nixon Reimposes Partial Freeze / Bunker Hill Baghouse Fire

Nixon reimposes a temporary freeze on labor / wage costs, but omits raw materials. 

During this time, the upgrades increasing the smelter's sinter and furnace capacities lead to the baghouse being unable to keep up with the increased processing load. This leads to high levels of lead contamination in workers. To remedy this, Bunker Hill adds more fans to the system, including one in the smoke stack. This increased vacuum power results in hot cinders from the furnace being pulled into the baghouse, igniting the September 3rd fire.


Bunker Hill Bypasses All Filtration Measures

Gulf Resources & Chemical Copr. holds a secret board meeting and decides to bypass the baghouse completely, operating the smelter without any pollution control. They choose to do this rather than shut the smelter down for repairs, the revenue to be made from increased lead prices at the time (and fixed wage/labor costs) outweighing - in their determinations- contamination costs. This choice was made despite their knowledge of the already high lead levels in area children, knowledge they obtained (unbeknownst to


Photo Credit: Bunker Hill Mine and Smelting Complex. (2023, August 7). In Wikipedia.

parents) through urine tests conducted via local, company-paid doctors. As a result, lead emissions increased to 35.3 tons per month,  compared to 8.3 tons per month recorded in previous years. (This 8.3 tons being what they were supposed to reduce by half as per the EPA mandate.)


Two children from the Silver Valley are taken to  Coeur d' Alene, ID where they are hospitalized for lead poisoning. This triggers reporting to the CDC. The CDC goes on to find 22% of the children within one mile of the smelter had more than 80 micrograms of lead per 0.1 liter of blood and almost all children in Kellogg have more than 40 micrograms per 0.1 liter of blood. (For reference, the CDC currently recommends public health actions be initiated when the level of lead in a child's blood is 3.5 micrograms per 0.1 liter of blood or more.)

TIFO co-founder, Ian von Lindern, is sent to Kellogg to conduct a lead study as an employee of Idaho's Department of Health and Welfare.

By year-end, Bunker Hill hits record revenue to the tune of $25 million (which equates to approximately $160,604,437 today).


Photo Credit: Bunker Hill Mine and Smelting Complex. (2023, August 7). In Wikipedia.


Baghouse Resumes Operation

The Bunker Hill baghouse is returned to operation.


In April, Bunker Hill mandates that employees with blood levels higher than 80 micrograms per 0.1 liter have 90 days to reduce those levels or they will be dismissed.

In December, the entire smelter is shut down for five days, unable to meet the EPA standards for Sulfur Dioxide.


Lawsuits Against Bunker Hill

In 1977 a lawsuit (Yoss and Dennis) is filed on behalf of nine children for harm from the lead smelter emissions. Going to trial in 1981, it is settled after more than a month. An additional suit (Prindiville) is brought on behalf of several dozen additional children and is similarly settled in 1983.


Photo Credit: Bunker Hill Mine and Smelting Complex. (2023, August 7). In Wikipedia.


1982 & 83

Bunker Hill Smelter Closes Indefinitely & Classified as a Superfund Site

In 1982 the smelter is closed indefinitely.

In 1983, Bunker Hill smelter and surrounding region is added as a Superfund Site to the National Priorities List by the EPA, initiating a massive remediation effort ongoing today.


TerraGraphics Environmental Engineering Established

Ian von Lindern and Margrit von Braun start the company TerraGraphics Environmental Engineering, contributing to decades of remediation work at the Bunker Hill Superfund site.

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Interested in learning more about the Bunker Hill Mine and Smelting Complex? Check out these resources:

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