WASHINGTON, D.C. — A proposed stricter standard on acceptable levels of cancer-causing dioxin in soil is confusing to some in scientific circles, alarming local governments and has Utah environmental regulators keeping a watchful eye.

The Environmental Protection Agency is considering adopting regulations which would make the "acceptable" level of dioxin in dirt a hundreds of times stricter than the current standard — potentially re-opening the door on cleanup that has essentially been closed on three Superfund sites in Utah.

Those sites are the old defense depot in Ogden, Wasatch Chemical in Salt Lake City and the north area of Tooele Army Depot.

Duane Mortensen, the Superfund branch manager for the Utah Department of Environmental Quality, said those sites are on the tail end of the remediation process — basically done — except for mandated five-year reviews to ensure public health remains protected.

Any change in EPA regulations would require a re-examination of the site's condition, potentially costing more dollars.

"If they change the risk numbers for a particular contaminant, we would have to determine if the remedies are still protective (of public health) and then we would have to decide what else needs to be done," Mortensen said.

Dioxin is a family of chemicals found in soil, water and even in some food consumed at the dinner table. It is generated by activities as mundane as burning household waste or from industry such as smelters or coal-fired energy plants. Dioxin, according to the EPA, is most commonly introduced through soil erosion or storm water runoff in urban areas.

Although its presence from man-made sources has been reduced by as much as 92 percent since the late 1980s, the EPA is considering hiking the standard, even in advance of a study that is due out in December.

That approach, according to the American Chemistry Council, is "scientifically flawed," because it forges ahead of the reassessment to examine risks associated with dioxin. The council cited potential impacts to the U.S. food supply, cities, states, business and the economy.

"For the life of us here, we can't figure out why EPA is doing what they are doing," said David Fischer with the American Chemistry Council. "The longer the EPA has taken on this reassessment, the less of a problem dioxin really is. That is sort of the part that gets lost."

The proposal has led the U.S. Conference of Mayors to sound off in opposition, asserting that a baseless change in rules would imperil the status of Superfund projects across the nation, and deter economic development on so-called "brownfields" — zones struggling with a legacy of industrial use.

In Ogden, where the site of the former Defense Depot Ogden was nominated to the EPA's Superfund list in 1984, cleanup is done and soil remediation deemed finished.

It is one of the sites in Utah where dioxin was listed as a "contaminant of concern," and removal of dioxin from soils is below the current threshold of a thousand parts per trillion, or in more understandable terms, one part per billion.

At those current levels, Fischer said he does not believe dioxin represents a public health threat through its presence in soil, which has not been a typical exposure route either.

"There's a real question for us — of what is the danger that needs to be addressed and how (changing the standard) would be more protective of human health," Fischer said. "This is going to create a lot of problems for sites folks thought were cleaned up and solved."

This year, for cleanup at the depot site in Ogden, the Department of Environmental Quality, the EPA and the military signed off on an amended groundwater-monitoring plan. Instead of assessing contamination through a pump and treat method, the monitoring has now shifted to simple sampling of the groundwater. Dioxin, at this stage, is no longer listed as a concern for the site, which spans 1,100 acres and is now home to an industrial park that has been deeded to the city.

Ogden, too, has its fair share of "brownfields," which are like contamination toddlers in comparison to the giant Superfund designations.

Brownfields are areas where redevelopment has been hindered because of real or perceived contamination. Ogden was one of the latest recipients of a $400,000 brownfields grant from the EPA to conduct an assessment of its west-side industrial area.

Many of the properties have sat abandoned for years, stifled from development by investors fearful they'd be buying up a cleanup process with an exorbitant price tag.

Tom Christopulos, the city's economic development manager, agreed that any change in the EPA's rulebook could escalate costs.

"Will it drive up the cost of remediation worse than it already is? Remediation is still an expensive process and it's that process that leads to the significant challenge of economic development."

The city has two remediation zones that have just been completed, but many more loom in the future.

"The biggest challenge we have economically is you increase the level of unknowns and the level of uncertainty. Nobody wants to finance something that is uncertain."

While DEQ's brownfields manager William Reese said he was unaware of any sites in Utah where dioxin is a concern, he — like others — are waiting to see what the EPA does and what implications may follow.

Concerns in other areas of the country have prompted strongly worded requests for the federal agency to back off its plan to impose stricter standards.

Oklahoma environmental regulators sent a letter to EPA, insisting the "current proposal would add to the remedial roadblocks already in place."

Christopulos said the imposition of stricter standards would be like "wandering through a mine field over the next year. I don't need any more hurdles."

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