The Environmental Protection Agency is proposing the city's vast collection of toxic mine tailings be capped with a five-foot layer of clay, according to the EPA's regional office in Denver.
The recommendation is detailed in a proposal the agency mailed in a Friday "air bomb" to some 1,200 residents of Midvale, according to Sam Vance, the EPA's project manager for the Sharon Steel site. The city has long awaited some action on the problem.Vance said a clay cap is by far the most economical of all practical alternatives for dealing with the tailings, which are the legacy of years of ore-processing in Midvale. City officials estimate that by the time the almost 100-year-old industry ground to a halt in 1977, some 10 million tons of tailings had piled up at the center of milling operations, a 270-acre tract of land just west of I-15 in the vicinity of 7800 South.
Today it is a desolate moonscape, though its presence is hard to ignore because the wind carries dust from the tailings onto property in the area. As part of a separate cleanup effort, the EPA and the state Department of Environmental Quality this summer will start replacing tailing-tainted soil on some 1,000 properties around the city.
Vance and other government officials will present the EPA's formal tailings-cleanup proposal at a Wednesday, June 17, public hearing, which begins at 7 p.m. at the Midvale Middle School auditorium, 138 Pioneer St.
"We want to do the right thing, and all the information we have in this plan we're laying out is that this is the right thing," said Vance.
Of five possibilities considered, capping the material is "the best balance," he said, because it would let the site be used for recreational purposes, though it would not be geologically stable enough to allow buildings to be constructed. City officials have already said the area, adjacent to the Jordan River, would lend itself to a parklike development, and some have suggested a golf course be built there.
Vance said that a clay cap would seal the tailings, protecting humans from toxic heavy metals such as lead and arsenic.
He said price was a profound consideration in the EPA's recommendation, and that some alternatives would cost on a per-acre basis "more than the price of real estate in downtown Tokyo." An EPA cost analysis that includes 30 years of maintenance put these price tags on each alternative:
- The "do-nothing" tack, which would leave the tailings as they are and maintain the site - $1.6 million.
- A "site-control" alternative, which would consist essentially of building a fence around the tailings, applying an annual dust suppressant and doing some landscaping - $6.2 million.
- Transporting the tailings by slurry line to anyplace within 30 miles - $224 million. A popular idea involves moving the tailings to the Great Salt Lake, where they might be used as the foundation for a causeway to Antelope Island.
- Capping them with clay - $54 million.
- A "fixation" alternative in which tailings would be mixed with some other material to prevent them from leaching into groundwater - $2.3 billion.
The EPA didn't include a cost figure for a high-tech vitrification process that would turn the tailings into glass, but Vance said its price tag would be "higher than any of the others."
Vance noted that as a result of a $64 court settlement paid in 1990 by three companies considered responsible for the tailings, EPA has almost enough money to pay for the capping. The yard cleanup, pegged at $22.5 million, is supposed to come out of the same settlement, and a separate slag cleanup is expected to cost about $5 million.
He said the more expensive alternatives would require money from the EPA's Superfund, for which there is great competition. States have to pay a 10 percent match of whatever money is taking from that fund. The EPA nonetheless will entertain any proposal by the state division to move the tailings to another site, Vance said, though the state would have to initiate further study of that alternative.
The state, according to Vance, has agreed by September 1993 to present any case it may make for moving the material, and the EPA at that time will render a final decision.
"The whole valley is suffering a severe case of NIMBY (Not In My Back Yard)," said Vance. "After everybody's had their say you may find the best place to put those tailings is exactly where they are."