Engineering Inc. - July/August 2007 - 20

W e are still required to do the work to the standards of the profession, regardless of where it is.” site at all times, from the beginning to the end of the project. “We pulled together our most senior staff who had some 20 to 30 years of experience people who had the experience of working in such conditions,” says Fagg. Iron Mountain afety was a primary concern for everyone who worked on the project.” KAren fAGG hkm s Perry sMItH Collins EnginEErs whose job it was to ensure that whatever technology the teams on the mountain needed was made available to assist the engineers on site. What’s more, the most experienced engineers and safety experts were assembled and directed to be on the In its 100-year history, the Iron Mountain Mine was noted for being the most productive copper mine in California, and one of the largest in the world. However, since the mine closed in 1963, the 4,400-acre site, located in the southeastern foothills of the Klamath Mountains, near the city of Redding in the northern part of the state, became known more for its designation as the largest source of surface water pollution in the U.S. Besides mining for copper, the mine also produced gold, zinc and pyrite (iron sulfide). Although the mine’s waste runoff did not pose a health threat to the residents of nearby Redding, the “most corrosive water in the world” according to the Environmental Protection Agency (EPA), was responsible for numerous fish kills in downstream rivers and streams. Now, more than 20 years of pollution control and remediation work by EPA and other federal and state agencies—much of it underwritten by Superfund—has neutralized almost all of the acid mine drainage and controls are in place to stop 95 percent of the copper, cadmium and zinc that previously flowed into nearby streams and the Sacramento River. Needless to say, for engineers, working in such an environment posed risks. There were numerous waste rock and tailings (ground rock and process effluents) piled on hillsides—which made the terrain unstable—coupled with massive fracturing of the bedrock overlaying existing underground mines and sinkholes. The mine itself was especially hazardous due to extensive unstable mine workings and 10, 200-foot-wide by 200-foot-high rooms that would periodically collapse on each other, causing the mountain to settle in on itself. “Safety was the highest priority for our firm and the EPA,” notes John Spitzley, principal project manager for CH2M Hill, a firm contracted to perform engineering support projects under the EPA. The Englewood, Colo.-based company is now in its ninth year of a 10-year contract. “This was an unforgiving property, so it was important to follow precisely established safety procedures inside the mine,” 20 ENGINEERING INC. July / AuGust 2007 WAtHIq KHuzAIe/Getty IMAGes
Engineering Inc. - July/August 2007

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