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Updated: Jan 11, 2020

Note: This essay was contributed by Marianne Sullivan, MPH, a researcher, teacher and epidemiologist. Marianne’s dissertation on ASARCO’s Tacoma/Ruston smelter is cited frequently in our work. Her book, Tainted Earth: Smelters, Public Health and the Environment, was published by Rutgers University Press in 2014.

The Tacoma smelter was one of the country’s most polluting nonferrous smelters. In its century of operation in Ruston, Washington (1890-1985), it produced lead, copper, arsenic trioxide, sulfuric acid and precious metals. Primarily a copper smelter, the Tacoma smelter was unique for several reasons: it was able to process ore with a high arsenic content; it was the only U.S. producer of arsenic trioxide after 1965; and it was located in an urbanizing area.

The environmental consequences of nearly a century of smelting are widespread, including: arsenic, lead and other heavy metal contamination of mainland soils; contamination of islands and sediments in Puget Sound; and arsenic-containing slag, dispersed throughout the region. Social consequences include: residents’ concerns about health, as awareness of potential exposure to toxins has been introduced into every day activities; law suits against ASARCO; concerns about property values; and public questioning of the government agencies that were charged with regulating the plant and protecting the public’s health.

In its century of operation in Tacoma, the ASARCO plant was never adequately regulated. Throughout the 1970s and '80s, the company successfully used threats of closure and job loss as bargaining chips to forestall regulatory action that would have required cash outlays to upgrade the aging, heavily polluting facility. During the uncertain economic climate of the 1970s and early 1980s, this tactic worked to sway public opinion to some extent, as well as many regulators and elected officials.

This short article briefly describes the struggles of citizens, activists, environmental groups, lawyers, and some government officials, throughout the twentieth century, to regulate the noxious mixture of sulfur dioxide, lead, arsenic and other heavy metals that spewed from the smelter’s tall smokestack, imperiled the health of Puget Sound residents, and despoiled the environment.

The Early Years

Emissions from the smelter’s smokestack killed off natural vegetation in the area, damaged gardens, and contaminated locally grown food. Calls by citizens to curtail the pollution date back to the early part of the twentieth century. By 1905, complaints about the “smoke nuisance” would cause the company to rebuild the smelter stack, making it the tallest concrete chimney in the world, in an attempt to dissipate the sulfurous and heavy metal laden fumes.[i] In 1916, Tacoma neighbors organized the “North End Improvement Club” to protest smelter fumes that blanketed the area.[ii] The following year, the stack was raised again, this time to 571 feet. ASARCO assured angry neighbors that this new, taller stack would solve the problem. Increasing the height of the smokestack to effect better dispersion of contaminants was ASARCO’s favored strategy for mitigating sulfur dioxide related air pollution complaints. At many of their smelters in the West, they relied on this approach for “pollution control” and funded an extensive research department which helped convince government officials that “dispersion” was an effective approach to limiting damage to agriculture and forest land surrounding smelters. Though technology was available early in the century to capture sulfur dioxide emissions, ASARCO resisted this solution at Tacoma, and many of their other smelters in the West because they felt that it would not be profitable.

In the first half of the 20th century, despite episodic citizen anger and complaints to the local health department and elected officials, the Tacoma smelter was not required by any government entity to capture its sulfur emissions. In the early 1950s, they installed a recovery system that captured about 18% of input sulfur, but this did little to solve citizen complaints. Until the late 1960s, Tacoma leaders maintained that they had no power to act to control the smelter’s emissions, as it was located in the separate town of Ruston, outside of the city’s jurisdiction.

Sulfur dioxide was the pollutant that was most noticeable to the community, as it seared lawns, killed gardens, exacerbated asthma and respiratory conditions, and provoked choking sensations. Sulfur dioxide from the Tacoma smelter was also a chief contributor to acid rain in the region.

Air Pollution and the Tacoma Smelter Post-World War II

After World War II public consciousness nationwide of air pollution began to change. Industry contended that air pollution was simply a nuisance, and not a threat to health, as ASARCO did in Ruston/Tacoma. But after several air pollution disasters, some involving smelters (e.g. Meuse Valley, Belgium, Donora, PA), the public increasingly linked air pollution with health damage.

by the late 1950s this changing conceptualization of air pollution was reflected in citizen organizing in Tacoma. By then, a post-War population boom meant that more housing was being built in the path of the smelter’s summer smoke stream, and the smelter’s location was becoming decidedly disadvantageous. Though ASARCO fostered loyalty in many local residents, others began organizing to protect health and property from damage from SO2 and later, heavy metals. in the late 1950s and throughout the 1960s, concerned Tacoma residents lobbied local, state and federal officials—to little effect—to gain relief, mostly from sulfur dioxide. Despite the efforts of citizen activists from North Tacoma, neither the city of Tacoma nor the state of Washington took concrete steps to abate the smelter’s pollution during this time period.

The introduction of local, state and federal environmental regulation

With the introduction of modern environmental regulation in the late 1960s and early 1970s, new dimensions were added to what was by then an old debate over reducing the smelter’s sulfur dioxide pollution. Ostensibly, local, state and federal regulators had the authority to reduce the plant’s emissions. At the local level pollution control authority was vested in the Puget Sound Air Pollution Control Agency (PSAPCA).

Organized environmental groups became involved in regulatory struggles in the late 1960s and early 1970s. The Washington Lung Association played a leadership role, and in the mid-1970s, more groups became involved, including local advocacy groups from Tacoma and Vashon Island such as GASP (Group Against Smog Pollution), APE (Americans Protecting the Environment), IRATE (Island Residents Against Toxic Emissions), the Sierra Club and Friends of the Earth. Clean Air for Washington and the Washington Environmental Council used the courts to try to press for controls. Their combined advocacy and oversight made it clear that the actions of ASARCO and regulatory agencies were being closely monitored. PSAPCA’s relatively modest regulatory accomplishments with respect to the smelter probably would not have been possible without citizen advocacy.[iii] Additionally, citizen legal challenges established some important precedents for environmental law in the state.

The 90% Standard for Sulfur Dioxide

Shortly after PSAPCA was formed, reducing emissions from the Tacoma smelter became the agency’s number one priority. The smelter was the largest source of SO2 pollution by far in the Puget Sound region—in the mid-1970s, PSAPCA said it was responsible for 85% of the region’s SO2 emissions.[iv] The agency rejected a request by ASARCO to build a 1,000 foot stack, rather than capture sulfur emissions. PSAPCA had determined, based on research conducted by the federal government, that ASARCO could feasibly capture 90% of input sulfur. This rule was also adopted in other smelting states. Industry fought the rule fiercely, and also fought its incorporation into the federal Clean Air Act; this helped to undermine EPA’s enforcement of PSAPCA'S standard. Though PSAPCA never changed Its expectation that ASARCO would capture 90% of its sulfur emissions, the company successfully used threats of closure to gain extensions to compliance deadlines. When the Tacoma smelter closed in 1985, it was capturing, at best, about half of input sulfur, and often not meeting the looser federal standard of 51%.

Regulating arsenic in air

Arsenic and other heavy metal emissions from the Tacoma smelter were a related but separate problem to that of sulfur dioxide. The Tacoma plant was one of the largest humanly produced sources of arsenic in the world. After the introduction of high arsenic copper ore, probably in 1913, until controls (electrostatic precipitators) were installed, arsenic emissions may have been between 35 to 67 tons per day.[v]

The smelter’s toxic metal emissions remained unregulated until the 1970s. Up until then, government officials basically took the company’s word for it that toxic metal emissions were well controlled. ASARCO did install electrostatic precipitators (EPs) to capture heavy metals, the first one in 1918, and two more in later decades. Electrostatic precipitators capture heavy metals from smelter smokestreams through the use of electrical charges.  Captured metals, such as arsenic, could then be sold at a profit.

The EPs functioned as a pollution control device and captured a portion of the smelter’s toxic metals, but when studies were conducted in the early 1970s, ambient arsenic concentrations in Tacoma were measured at eight times the national average.[vi] The University of Washington researchers who conducted the study urged that a standard for arsenic in air be set. At the time, arsenic was known to cause skin cancer, and evidence was accumulating that it was a respiratory carcinogen. Today, arsenic is known to cause cancer in many different organs.

The discovery of elevated arsenic concentrations in the urine of children who lived near the smelter’s stack in 1972 led to calls from state and local health departments, among others, [vii] for PSAPCA to regulate the smelter’s arsenic emissions. In addition, state and local health department investigators and other researchers had identified significant environmental contamination with arsenic in the region in the early 1970s.

PSAPCA favored the prompt adoption of an ambient air standard for arsenic, and enlisted EPA’s assistance in this effort. [viii],[ix] The agency was already engaged in discussions with ASARCO on lowering their heavy metal emissions, and had recommended that they “…make all reasonable efforts to abate emissions of arsenic and lead to the lowest level practicable by application of the best available technology.”[x] At the time, there was no legally enforceable federal, state or local standard that would have put a limit on arsenic emissions.

In the early 1970s limited air sampling for arsenic ifound arsenic concentrations taken 2 miles from the smelter averaged 1.5 μg/m3. The maximum concentration was 9.8 μg/m3, 89 times higher than the U.S. urban average. Even in the area beyond two miles from the smelter, the maximum concentration was close to 2.0 μg/m3.[xi]

By early 1973, PSAPCA believed that ASARCO was emitting about 1,000 pounds of arsenic per day from the tall stack. But the agency had yet to estimate emission rates or measure ambient air concentrations of other toxic metals present in the smelter’s emissions such as mercury, copper, lead, and cadmium.[xii]

Setting a Local Standard for Arsenic

PSAPCA thought that EPA’s standard-setting process for arsenic could take up to a year or more, and the agency wanted to achieve control of arsenic emissions in a more timely fashion. Public hearings were held in February of 1973, and a plan was adopted for upgrading the plant’s pollution controls.

Over the decade of the 1970s, arsenic emissions from the smelter’s tall stack decreased because of the control requirements imposed by PSAPCA. But ASARCO never installed a baghouse for tall stack emissions—a proven pollution control technology that would have significantly increased capture of the plant’s toxic metals.[xiii] In addition, fugitive, or low level emissions remained a significant problem.

The presumption of health officials and PSAPCA was that controls :installed by ASARCO would lead to declining urinary arsenic concentrations in Ruston children. However, Dr. Sam Milham of the Washington State Department of Health determined in 1976 that children’s urinary arsenic concentrations were not declining as expected. [xiv] In a letter to PSAPCA, Milham wrote:

"For comparable groups, arsenic levels are about the same now as they were four years ago. If the extensive emission control activities undertaken by the Smelter have had an impact on overall community arsenic exposure, I cannot demonstrate it in this urinary arsenic data … I conclude that Ruston children are still being exposed to very high levels of arsenic in their environment."[xv]

EPA Involvement

Within EPA Region 10 some staff were very concerned about the impact that the smelter’s toxic metals emission might be having on the health of the region’s residents. In January of 1974, in an effort to direct resources toward the problem, a regional staff member wrote:

"The ASARCO Smelter pours tons of material into the atmosphere daily. Among the pollutants emitted are known to be Pb (lead), Hg (mercury), Cd (cadmium), and As (arsenic), all of which are toxic materials. A potential public health problem of unknown extent exists in this area."[xvi]

By the end of 1974, EPA Region 10 had designated the Tacoma smelter “the number one air pollution problem in the Puget Sound region.”[xvii] But the Region’s elevation of the problem did little to get EPA headquarters moving expeditiously. Headquarters was skeptical of the carcinogenic threat posed by airborne arsenic. The regulation of heavy metals, with the exception of lead, came under the air toxics provisions of the Clean Air Act. To regulate it, arsenic would first have to be declared a hazardous air pollutant and then Headquarters would have to promulgate a standard. EPA was taking a very conservative approach to regulating air toxics– between 1970 and 1990 the agency set standards for just seven hazardous air pollutants.[xviii]

The slow pace on regulating arsenic by EPA Headquarters, justified on the basis of inadequate scientific evidence, appeared to be at least in part political, since EPA was alone among federal regulatory agencies in their skepticism with respect to the science on arsenic’s carcinogenicity.

When EPA missed an August 1978 deadline to decide on listing arsenic as a hazardous air pollutant, the Environmental Defense Fund filed suit, asking the court to order EPA to declare arsenic a hazardous air pollutant or detail why it would not.[xix] It would take EPA until June of 1980 to declare arsenic a hazardous air pollutant. Almost a decade had passed since Region 10, local regulators and environmental groups had first asked for Headquarters’ help on regulating arsenic.

The 1980s saw vigorous debate over the extent to which the smelter would clean up its arsenic emissions. After remaining relatively hands-off in the 1970s, EPA Headquarters took a prominent, but controversial role under the leadership of Administrator William Ruckelshaus. With the expressed intent of promoting public participation in environmental decision-making, EPA held public meetings to ask whether residents favored further pollution controls, or plant closure and job losses. In the end, EPA took so long to promulgate a final regulation for arsenic that the plant shut down in 1985 before federal regulation occurred.

The failure to adequately regulate the smelter’s considerable arsenic releases meant that throughout the 1970s and '80s, until the smelter closed in 1985, ambient air concentrations remained high, as did concentrations of urinary arsenic in children.

Both before and after 1970, government agencies approached the problem of the Tacoma smelter’s emissions from the perspective of weighing the costs and benefits of pollution control. Without definitive evidence of health problems in the community, relative inaction could be and was justified, and the burden of proof that health was being harmed was largely on the community. The immediate costs to industry of pollution control were prioritized over the substantial costs—both immediate, and long term—to the region’s residents. The Tacoma smelter’s legacy of pollution remains an on-going challenge, as regulators and environmental scientists grapple with how to reduce exposure to and clean up the vast quantities of toxic metals that now contaminate the region’s soils.

Tacoma, WA: Health Department campaign against lead and arsenic exposure


[i] “Mammoth New Chimney Just Completed at Tacoma Smelter,” The Daily Ledger (May 7, 1905), 4.

[ii] H.Y. Walker, Tacoma Smelter Manager to Mr. Karl Eilers, Vice President, ASARCO, “Internal ASARCO Correspondence,” (September 20, 1916), Branin v. ASARCO.

[iii] Arthur Dammkoehler, interview conducted by the author, (July 20, 2005), digital audio recording, Mercer Island, Washington, file in author’s possession.

[iv] Puget Sound Air Pollution Control Agency (April 22, 1974), The Concentration of Lead, Arsenic, Mercury, Cadmium, Sulfur Dioxide and Suspended Sulfates Downwind from the Tacoma Smelter, the Impact and Control Status, and Benefits from Reduction, Interim Report for Presentation to the ASARCO Impact Task Force Being Coordinated by EPA, 28, Environmental Protection Agency Site File, Commencement Bay/Nearshore Tideflats ASARCO Smelter Facility Site File, hereafter referred to as ASDSF, 1.6.3.

[v] Estimates of historic emissions for the Tacoma Smelter have not been made in the published literature. Glass in the Washington State Department of Ecology’s Credible Evidence Report invites the reader to make comparisons with Anaconda, which emitted up to 75 tons of arsenic per day prior to installing Cottrell electrostatic precipitators. In a personal communication with this author, Glass estimated that prior to the installation of EPs, based on estimates of throughput and slag output, emissions of arsenic to the air could have been between 37 and 67.5 tons per day. However, the arsenic content of ore in the early years of the smelter’s operation is not well documented; Gregory L. Glass, environmental scientist, written personal communication, (February 1, 2008), in possession of author.

[vi] H. Alsid, B. Amundson, G. Hofer, D. Lutrick, “The Tacoma Air Pollution Study (July-August 1970),” (September 30, 1970), Air & Resources Program, Water and Air Resources Division, Department of Civil Engineering, University of WA, Seattle, University of Washington Special Collections, American Lung Association Records, 5271-1 B4 F15.

[vii] Wallace Lane, MD, to Arthur Dammkoehler and Board of Directors, PSAPCA, “Letter,” (November 9, 1972), ASDSF 1.1.1.

[viii] Arthur Dammkoehler to Wallace Lane, MD, “Letter: Lead and Arsenic Studies, Vicinity of ASARCO Copper Smelter,” (November 13, 1972), ASDSF 1.1.1.

[ix] Arthur Dammkoehler to James Agee, Administrator, Region 10 EPA, “Letter: Request for EPA Technical Assistance in Establishing Ambient Air and Emission Standards for Arsenic,” (November 14, 1972), Environmental Protection Agency Site File, ASARCO Administrative Record, Microfilm, hereafter referred to as ASAR, with microfilm number and start frame number following, ASA 208 1375.

[x] G.C. Hofer, M.J. Svoboda, A.E. Parlier, R.D. Pollock, Puget Sound Air Pollution Control Agency “Interim Report: Lead and arsenic content in the soil affected by the copper smelter located in Tacoma, Washington,” (October, 1972), King County Archives, Box Health Department Director Issue Files 68-79, Folder 10 Lead Poisoning 1972-79.

[xi] Puget Sound Air Pollution Control Agency, “Staff Report: Section 9.19 Regulation I Arsenic Emission Standard,” (February 14, 1973), ASDSF 1.1.1.

[xii] Ibid.

[xiii] John W. Roberts, Air Pollution Engineer to Chief-Engineering, “Internal PSAPCA Memorandum: Arsenic and Particulate Emission Reductions Possible with Baghouse on Tall Stack at ASARCO,” (June 16, 1975), Ecology electronic files.

[xiv] Samuel Milham, Jr., MD to Arthur Dammkoehler, “Letter,” (October 1, 1976), ASDSF [Three tables with urinary arsenic concentrations attached].

[xv] Ibid.

[xvi] James Everts, Research & Development Representative, Region X, Requestor, “Environmental Research Needs: Hazard Evaluation of the Tacoma, Washington, ASARCO Copper Smelter” (January 31, 1974) Environmental Protection Agency Site File, Commencement Bay/Nearshore Tideflats, ASARCO Administrative Record, hereafter AR, 1.1.

[xvii] Terrance R. Strong to Smelter Task Force, “Meeting Minutes: Smelter Task Force Meeting,” (December 18, 1974), ASAR ASA 211 Frame 1437.

[xviii] K.W. Olden, and J. Guthrie, “Air Toxics Regulatory Issues Facing Urban Settings,” Environmental Health Perspectives 104 Supplement 5 (1996), 857-60.

[xix] “Group Seeking Limits on Arsenic in the Air Files Suit Against U.S.,” Wall Street Journal (August 16, 1978), 3.


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