Buried Treasure

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WHEN RESERVE MINING sought to build the first taconite processing plant in the late 1950s, it looked no further than Silver Bay, a lakeside town 50 miles north of Duluth. Lake Superior offered both a source of water for the refining process and a convenient place to dump the pulverized leftover rock, known as tailings.

A decade later, fishermen and resort owners began reporting a greenish slime in the lake. The National Water Quality Laboratory, only recently established in Duluth, launched an investigation, which concluded that the discoloration was caused by taconite tailings. The newly formed Sierra Club filed suit against the similarly novel Minnesota Pollution Control Agency, demanding that it take action. In 1971, the MPCA, headed by Grant Merritt, grandson of one of the Seven Iron Men, started monitoring the water.

The following year, the U.S. Environmental Protection Agency released a study reporting that "asbestos-like fibers" had been found in Duluth's drinking water.

The case went before Miles Lord, the storied activist federal judge. Among those testifying for Reserve was Edward Davis, the father of taconite and a Reserve employee. He insisted the tailings were harmless.

But Lord caught the company in a lie. While its officials insisted under oath that Reserve Mining had never considered dumping its tailings on land, internal documents initially withheld from the court showed otherwise.

Lord used the inconsistency to take the company to the woodshed. In a landmark ruling, Lord ordered Reserve Mining to stop dumping its tailings in the lake. Complying with the verdict took several years and cost more than $300 million. In 1987, the struggling company went bankrupt, putting thousands out of work.

Reserve wasn't alone. As taconite companies lowered production in response to weakening demand, the number of mining jobs plunged from 14,000 in 1979 to just 3,000 five years later.

While market forces—and, later, technological advancement—were to blame for most of the job losses, many blamed Reserve's demise on the federal court ruling. Judge Lord, for his part, never apologized for his hard line. "The only protection is to make it too expensive to kill," he said in an interview years later.

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AS WITH IRON, the discovery of copper in northeastern Minnesota was accidental. In the late 1940s, a work crew carving out a road for logging hit a nugget of shiny rock just below the surface. The workers had stumbled upon the edge of what geologists call the Duluth Complex, a chunk of bedrock dating to the Midcontinent Rift, a rip in the earth's surface 1.1 billion years ago. The rift caused cracks in the floor of what would later become Lake Superior. As the magma spewed out, the heavy, sulfur-bonded metals sank to the bottom. The road crew had struck the edge of the rock formation, where the sulfides had settled nearest to the surface.

As word of the discovery spread, interest grew. By the mid-1960s, more than a dozen companies had snapped up mineral rights on a patchwork of federal, state, and privately owned land. Planning to mine copper and nickel both underground and in open pits, the companies drilled feverishly in a 95-mile band of bedrock extending north and east of Duluth.

But in 1974, when two companies announced plans to apply for permits to start mining, the state's Environmental Quality Board intervened. Fearful of unintended consequences, the agency put a moratorium on copper-nickel mining to allow time for a comprehensive study of the potential downsides. The review lasted five years, cost $4.3 million, and yielded a staggering 180 reports organized into five volumes.

"We did all sorts of crazy things that most people never even knew about," recalls Steve Piragis, who worked on the study as a young biologist. "We even had microphones along the road in downtown Ely to measure ambient noise."

The team of scientists identified two major environmental threats. First was acid mine drainage: The excavated waste rock, rich with heavy metals and sulfur, threatened, if exposed to both air and water, to poison the rainwater and groundwater flowing into surrounding streams, rivers, and lakes. Second, melting the crushed rocks under extreme heat to separate the metals would release sulfur dioxide, a toxic gas that would spread over nearby forests and watersheds, leaving a trail of acid in its wake.