Water is Minnesota's No. 1 natural resource. Stories about our surface and groundwater resources appear almost daily. As Minnesotans consider the prospect of copper-nickel mining in the Lake Superior and Rainy River watersheds, the latter including the Boundary Waters Canoe Area Wilderness and Voyageurs National Park, it's worth recalling the state's longest-running mining industry dispute ended on March 16, 1980. That day Reserve Mining Co. stopped dumping 67,000 tons a day of taconite tailings into Lake Superior. Reserve, the first taconite-processing facility in North America, had discarded tailings into the world's greatest freshwater lake beginning in 1956.

For nearly 25 years, an incredible volume of tailings was dumped — the equivalent of a railroad car every two minutes. It's hard to appreciate that quantity of waste entering Lake Superior unless you observed firsthand this roaring deluge of black, mucky tailings.

Today, taconite pellets produced at the Silver Bay plant — now operated by Northshore Mining — are shipped on the Great Lakes to blast furnaces in Indiana and Ohio. Northshore, owned by Cleveland-Cliffs Inc., is the principal employer in the area and one of six Minnesota taconite operations.

Northshore's tailings basin is several miles inland, unseen by tourists traveling Hwy. 61. Silver Bay touts itself as "the best of the North Shore," including Black Beach, the Gitchi Gami State Trail, Palisade Head, the Baptism River and three state parks. The Silver Bay Marina protects watercraft from storms on the mighty inland sea of Superior. Part of nearby Tettegouche State Park was once proposed as the tailings disposal site. Then-Gov. Wendell Anderson said no after a midwinter trek in the area with snowmobiles and many attorneys. The Nature Conservancy later protected the area, leading to the state park designation.

Today's coexistence of taconite production and tourism in Silver Bay was dramatically different in 1969, when the first enforcement action began against Reserve Mining. The conflict continued into 1977, when the state, under court order, issued permits for Reserve to deposit its tailings at the Mile Post 7 site. The intervening years were tumultuous — lawsuits in state and federal courts, constant media attention, threats against state officials, uncertainty for Reserve's employees, bottled drinking water for Duluth residents when asbestos-like particles were found in the tailings, the removal of a U.S. district judge and tension among DFL Party officials.

Not until the PolyMet and Twin Metals projects has there been as extensive media coverage and friction between proponents and opponents of a mining venture. The stakes — jobs, economic development, environmental impact and the credibility of regulatory agencies — are enormous.

Six books have been written about the Reserve case. The most recent is "Iron and Water" (University of Minnesota Press) by Grant Merritt, the commissioner of the Minnesota Pollution Control Agency from 1971 to 1975. Merritt is arguably the most important individual in the conflict as a citizen advocate, lawyer and state official. His perseverance to get the tailings out of Lake Superior cannot be overstated. Merritt devotes a dozen chapters in his 2018 book to the Reserve case.

The Reserve battle was well-known to Minnesotans in an era before the internet and social media. The Star Tribune and Pioneer Press archives include hundreds of articles. There are 138 boxes of documents at the Minnesota Historical Society.

The case occupied public officials, including Anderson and Gov. Rudy Perpich, Attorney General Warren Spannaus, leaders in the Legislature, U.S. Reps. John Blatnik and Jim Oberstar, federal Environmental Protection Agency Administrator William Ruckelshaus, and federal judges Edward Devitt, Miles Lord and William Webster (later the director of the FBI and CIA). Anderson's first act as governor in January 1971 was to join the Lake Superior Enforcement Conference convened by the U.S. Department of the Interior to review the environmental effects of Reserve's dumping into Lake Superior.

Then and now

As Minnesota contemplates a new copper-nickel mining industry, is the Reserve Mining dispute relevant in the debate over proposals by PolyMet and Twin Metals?

Reserve's permits were approved in 1948, a different era of environmental awareness, to process taconite — low-grade iron ore — into pellets at Silver Bay and discard its tailings into Lake Superior. Federal and interstate water quality standards were not enacted until 1965. There was no comprehensive environmental impact review before the National Environmental Policy Act (1970) and its Minnesota counterpart (1973).

The assumption in Reserve's permit application was that the tailings were "mere sand" and would sink into the cold depths of Lake Superior, not migrate in the lake nor impact drinking water. Within a few years, local residents noticed increased turbidity. The tailings plume was migrating farther than the 9-square-mile area insisted in its permit by state Conservation Commissioner Chester Wilson.

As Merritt recalls in his book, "On many days it was easy to see the green water all along the shore toward Two Harbors as well as out in the open water of the lake toward Wisconsin." Citizen complaints were ignored by state agencies. Reserve's spokesman called the green water both an "illusion" and "a natural phenomenon." By 1968, citizen groups called on Reserve to stop lake dumping, as did the 1970 DFL Party platform.

The Lake Superior Enforcement Conference created by Interior Secretary Stewart Udall concluded that the tailings endangered public health. An Interior report in 1969 insisted that Reserve end its lake disposal in three years. Reserve's president told conference attendees that "no one is more interested in preserving the high quality of Lake Superior than Reserve mining." His words are similar to a 2015 commentary by the PolyMet CEO: "PolyMet is committed to developing Minnesota's first copper-nickel mine the right way. A way that is safe and protective of the environment."

The PCA began permit revocation proceedings in 1969. Reserve then proposed a "deep pipe" system 150 feet below the surface. The EPA rejected it and notified Reserve that it was in violation of federal water pollution standards. In 1972, the Justice Department filed suit against Reserve. Judge Lord closed the plant in April 1974, but his decision was overruled three days later by the Court of Appeals. Legal maneuvering continued. Reserve agreed in 1977 to build an on-land disposal site seven miles inland.

The nearly 10-year environmental review of the PolyMet proposal culminated last year with permits issued by federal and state agencies. Several state permits have been challenged in court by citizen groups. In the Reserve case, the citizen groups were allies of the regulatory agencies while urging the earliest date to end the dumping of tailings.

Reserve had operated for a dozen years, albeit violating its permit, before the public health impact of its tailings was formally challenged. The company employed hundreds at its Babbitt mining and Silver Bay processing operations. Economic arguments were pivotal in the Reserve case as with the prospect of copper-nickel mining.

Other than several days in 1974, the plant did not close, although Judge Devitt did so order in 1977 if an on-land agreement was not in place within a year. The Mile Post 7 site opened ahead of schedule in 1980. In 1986, Reserve declared bankruptcy, and the plant closed for several years. Northshore now produces 6 million tons a year there and is the first taconite company with a new pellet product following a $100 million investment by Cleveland-Cliffs Inc.

The Reserve case offers an important lesson to today's mining debate: Once an operation commences with employees and suppliers in place, it is difficult to stop. Regulatory agencies, citizen groups and tribal organizations all have more resources than in the 1970s. The mining industry and its political supporters are better organized to promote hard rock mining. And the rhetoric is more heated than in the Reserve era. As Star Tribune columnist Lee Schafer wrote recently, the copper-nickel battle is as much about politics as economics.

During the Reserve case, the PCA Citizens' Board considered land disposal sites and was an example of public decisionmaking on a complicated permit decision. In 2015, the Legislature terminated the Citizens' Board, without a public hearing, after it required additional environmental review of a proposed feedlot expansion. The refrain heard today from mining advocates about complying with Minnesota's "highest environmental standards" is less credible with the elimination of the Citizens' Board.

A distinction between taconite tailings and waste rock from processing of copper-nickel ores is that taconite deposits are generally chemically inactive. Spread across the Iron Range are tailings impoundments that are part of the industry landscape. There have been no major impoundment failures, although there are concerns that the PCA is not enforcing mercury and sulfate standards.

While the chemistry of the tailings was not a central issue in the Reserve case, the dimensions of the micron-sized tailings became a drinking-water and air-quality challenge, since they were indistinguishable from amosite asbestos, a known carcinogen. Long-term health impacts of these fibers remain an issue. In copper-nickel mining, the metals are embedded in rock, producing sulfuric acid when exposed to air and water.

Finally, Reserve was a joint venture of U.S. steel companies — Armco and Republic — that weren't named on the permits. The companies were involuntarily joined to the litigation and assessed costs for filtered water plus penalties. Requests to tie the corporate balance sheet of PolyMet's parent company, Glencore, to the permits for any future liability seem reasonable.

If anything, higher stakes now

The Reserve Mining case captivated Minnesota during the 1970s — the early years of the environmental movement — and was a test of legal strategy and resolve between state officials and a company with prominent corporate owners, significant economic impact and strong regional political support. Economic, public health and environmental impacts were ultimately balanced by the courts. The dispute was resolved with a solution that protected both jobs and Lake Superior, after tailings were dumped into the lake for 25 years.

Minnesota today is debating a new type of mining. But the consideration of the long-term consequences to the environment and economy, by elected officials, regulators and the courts, is no different than in the Reserve case. If anything, the stakes are higher.

When one drives by the Northshore plant in Silver Bay, taconite pellets are stacked high waiting for shipment. Here an incredible amount of waste materials was simply dumped into the lake — a total of more than 600 billion tons. From the first enforcement action in 1969 to stop this disposal, it took 11 years to turn off the tailings chutes.

There is little information in Silver Bay or nearby Tettegouche State Park about a dispute that consumed Minnesota for almost a decade. We hope there is an opportunity in the years ahead, at the 100-acre delta formed by the tailings and the park's visitor center, to inform Minnesotans about a monumental battle a half-century ago to protect Lake Superior.

Peter Gove worked for Gov. and U.S. Sen. Wendell Anderson and succeeded Grant Merritt at the Minnesota Pollution Control Agency. Robert Herbst was commissioner of Natural Resources during the Anderson administration and later was assistant secretary of the Department of the Interior. Eldon Kaul represented the PCA during the Reserve Mining case. David Zentner was a member of the PCA Citizen's Board from 1974-79 and is a past national president of the Izaak Walton League.