Friday, March 7, 2008 | 2 a.m.
At issue is particulate matter less than 2.5 micrometers in diameter, known as PM 2.5. It causes health problems. Federal limits on the amount of these particles allowed in the air have existed since 1997 but have never been enforced. The EPA is enforcing another standard, a limit on PM 10, particulate matter less than 10 micrometers in diameter but larger than 2.5 micrometers. Ten micrometers measure about one-seventh the diameter of a human hair.
Opponents of the coal-fired power plants proposed for Nevada say one of the public’s biggest concerns should be the tiny particles that will come out of the plants’ smokestacks.
The microscopic particles are produced during combustion by power plants, diesel engines and wood fires, and studies have found they can cause heart attacks, strokes and respiratory diseases.
In 1997, the federal Environmental Protection Agency placed limits on the amount of these particles, many times smaller than the width of a human hair, allowed in the air. After five years of courtroom battles, the regulation was upheld in 2002.
Four years later, confronted by evidence of the health risks, the EPA cut the allowed amount of the smaller particles nearly in half.
Even a lobbyist who represents Sithe Global, the company proposing the 750-megawatt coal-fired power plant near Mesquite, acknowledges the case for the much tighter restriction is solid.
“The science ... was pretty compelling, that they needed to set a lower standard even though they set one only eight years earlier,” said the lobbyist, Jeff Holm-
stead, a former EPA administrator.
Despite the compelling science, the EPA has never enforced the original limits, never mind the stricter new ones.
Even if the agency did enforce them, Nevada isn’t likely to come anywhere close to exceeding the new limits, Holmstead said. He added that modern coal-fired power plants such as the one his client intends to build in Mesquite will not significantly increase the levels of fine particles in Nevada’s air because these plants will have relatively low sulfur emissions and burn low-sulfur Western coal.
That doesn’t mean Nevadans have nothing to worry about, said Dr. Christian Hyde, a radiation oncologist who lives in St. George, Utah.
“Science doesn’t show a safe threshold level” for inhalation of these particles, he said. “The more exposed you are, the more the risk.”
According to a study of the health effects of fine particles on women’s health published in the New England Journal of Medicine in February 2007, for example, even small increases in levels of the particles cause measurable increases in heart attacks and strokes.
Hyde knew nothing about particle emissions until he started researching the pollutants that would be produced by the plant Sithe Global plans to build 90 miles northeast of Las Vegas. Hyde is now convinced health effects from emissions of the dangerous particles “should be specifically addressed before this plant is given an air permit.”
They won’t be.
Two kinds of particles are regulated under the EPA’s air quality standards: coarse particles about one-seventh the width of a human hair and much finer particles. But until the EPA comes up with a way to enforce a limit on the smaller particles, it has told states to use regulations limiting the coarser particles. So the final air permit expected to be issued within weeks by the Nevada Environmental Protection Division will regulate emissions of coarse particles from the Sithe Global plant but not the more dangerous fine particles.
According to an EPA Web site, Nevada is in compliance with the 1997 regulations limiting fine particles, while areas of Southern California less than 100 miles from here are not.
Using an estimate, the Nevada Environmental Protection Division in December reported to the EPA that the state meets the new, stricter limits. The EPA is expected to rule on whether it agrees with the state’s assessment by December.
Clark County Air Quality and Environmental Management has a more precise handle on fine particle levels; it measures them in the valley and has found they are typically well below the new limits. During the hotter months, however, the levels sometimes increase to about a third of the allowed amount, according to air quality data.
How Nevada’s air might be affected by new coal-fired power plants remains unclear, and could continue to be unclear even after they begin operating.
The problem is that what is emitted from the smokestacks can combine with other chemicals in the air to create more of the fine particles. They are so small they can form as a gas when sulfur or nitrogen combine with other chemicals. All of that makes for an airborne problem that is hard to measure and extremely difficult, if not impossible, to track back to an initial source, according to Greg Remer, chief of the Nevada Environmental Protection Division’s Air Pollution Control Bureau.
The upshot is that the EPA has no way to model how much of these fine particles will be created by power plant emissions, Remer said.
It is possible to measure and even capture the fine particles before they are emitted from a source such as a smokestack, but the EPA won’t require that until it has a standard in place for such sources.
“Just because there is a standard for it doesn’t necessarily mean that stationary sources (such as power plants) are the culprit,” Remer said. “We have to implement (the rule) how EPA tells us to implement it.”
The failure to enforce any limit on the smaller particles has resulted in many new power plants being built without state-of-the-art equipment that would help reduce those emissions, according to Abigail Dillen, an attorney with EarthJustice.
“The irony is that particulate matter is one of the things the industry has been controlling for years,” she said. “We have the technology. But EPA has been giving states and industry a free pass on this since 1997.”
“EPA has been dragging its feet on solving the (fine particle) problems for a decade already,” she said. “The more recent regulations they’ve put in place allow us to maintain the very dangerous status quo for 10 to 15 years in the future.”
That statement appears to be borne out by the EPA’s somewhat nebulous timeline for compliance.
Areas of the nation where the levels are too high will be required to submit plans to the EPA detailing how they’ll comply with the new regulations, according to Eleanor Kaplan, an air quality specialist with the EPA’s San Francisco office. Those areas will have five years to reduce the levels — but can apply for extensions if they can’t meet the deadline.