Issue Date: April 2, 2007
WHEN IT COMES to curbing air pollution, the Environmental Protection Agency historically has set the targets for cleaning up, and states have responded by implementing EPA's national goals. But the case of reducing mercury pollution from power plants shows that the tide is turning.
A number of states have decided that they can do more to protect public health than can EPA's rule. As a result, they are requiring deeper and faster cuts in mercury emissions than the federal agency has.
This is a precedent-setting change in U.S. air pollution policy, says Felice Stadler, manager of the mercury program at the National Wildlife Federation (NWF).
In addition, some states may end up putting a crimp in EPA's emissions trading strategy for reducing power plants' releases of the neurotoxic metal. Under this scheme, utilities can continue spewing mercury if they purchase allowances to pollute from facilities that have cut their releases to below required levels. A number of states are opting out of the national trading plan, others are challenging the scheme in court, and some are doing both.
In the U.S., coal-fired power plants are the largest source of mercury releases to the environment. Coal contains tiny amounts of mercury, generally less than 1 part per million, or between about 5 and 36 lb of the metal per trillion Btu of energy. Each year, U.S. power plants release about 48 tons of mercury to the atmosphere when they burn coal, according to EPA.
Policymakers are concerned about airborne mercury primarily because some of it deposits in watersheds. Both bacteria and abiotic chemical processes can convert deposited mercury into methylmercury, a form of the metal that can be taken up by fish. People, especially children and pregnant women, are advised to limit or avoid consumption of mercury-contaminated fish because the metal is linked to neurological problems.
Bush Administration officials express pride that they crafted the first regulation anywhere in the world to curb emissions of mercury from the electricity-generating sector. They repeatedly tout this Clean Air Act rule, which was issued in 2005, as a major environmental accomplishment.
EPA's rule is designed to cut current annual mercury emissions of 48 tons from power plants by 21% in 2010 and by 69% sometime after 2018, perhaps as late as 2025. Under the regulation, plant operators won't have to install equipment that specifically controls mercury until 2018. This is because the first round of cuts in mercury will come as a by-product of another EPA rule, one reducing utilities' emissions of sulfur dioxide and nitrogen oxides.
States say EPA's rule sets the bar too low. Stadler says states are demonstrating that it's possible to control mercury emissions from power plants within the current decade and not have to wait until 2018 or beyond.
NOT LONG AFTER the Bush Administration issued the rule, state and local air pollution regulators began pushing a plan for individual states to issue rules that would slash mercury emissions from power plants faster and deeper than does the EPA rule. The National Association of Clean Air Agencies (NACAA) developed the strategy to eliminate 80% of the mercury released from coal-fired power plants by 2008 and 90-95% by 2012. The group estimates its approach would add $1.00 to $2.00 to the monthly bill for residential electricity (C&EN, Nov. 21, 2005, page 8). The plan excludes the trading of mercury, says NACAA, which was recently formed from the merger of the State & Territorial Air Pollution Program Administrators and the Association of Local Air Pollution Control Officers.
State and local air pollution agencies prefer a strong, effective federal rule on mercury to provide the uniformity and certainty that electric utilities desire, says S. William Becker, executive director of NACAA. But state and local regulators "won't sit idly by when the federal government promulgates a deficient rule" like EPA's rule on mercury, he tells C&EN.
Some states are adopting even tougher measures than those in the NACAA plan. For instance, Connecticut has enacted a statute mandating a 90% reduction in mercury emissions by July 2008. Other states, however, are unable to adopt more stringent limits than the one set by EPA because of laws prohibiting them from setting environmental standards that are tougher than national ones, Becker says.
Meanwhile, 15 states are opting out of the national mercury-trading scheme established under the Bush regulation. Utilities in five of these states—Delaware, Massachusetts, New Jersey, New Mexico, and New York—likely would have purchased emission allowances if these states had joined the national trading program, according to an analysis by NWF.
Three of the 15 states opting out of the trading program don't have coal-fired power plants—Idaho, Vermont, and Rhode Island—but utilities have drafted plans to build two coal-burning generation plants in Idaho. Under the EPA rule, these new plants would have to purchase mercury emission allowances from facilities in other states before they could begin operation. Idaho is considering a rule that would restrict emissions of mercury from newly constructed coal-burning facilities.
Even though the federal trading program "isn't ideal" because of the states opting out of it, the scheme will still work as intended to lower the cost of cutting mercury emissions, says Jeffrey R. Holmstead, a former EPA assistant administrator who was the architect of the Bush Administration's 2005 mercury rule. "I'm quite confident of that," because most of the nation's coal-fired capacity is in states that buy and sell emission allowances, says Holmstead, a partner in the Washington, D.C., office of the law firm Bracewell & Giuliani, where he heads the environmental strategies group and consults with utility clients.
Most of the states opting out of the EPA trading program for mercury don't have significant coal-fired generating capacity, Holmstead tells C&EN. The exception is Pennsylvania, he says. According to the Energy Information Administration's (EIA) preliminary figures for 2006, Pennsylvania ranks fourth nationally in net electricity generation from coal, behind number one Texas, number two Ohio, and number three Indiana.
Stadler of the NWF agrees that the states opting out of the trading program won't disable the national scheme. But Pennsylvania and another major coal-producing and -burning state, Illinois, are showing that cuts in mercury pollution are possible through state action without participation in the federal trading system, she says. Illinois ranks sixth in the nation in net generation of electricity from coal, according to EIA.
Holmstead says Pennsylvania's new requirement for an 80% cut in mercury by 2010 and 90% by 2015, as well as its choice not to be part of the federal trading system, will be costly to the commonwealth's electric utilities and their customers.
STADLER SAYS the actions that states are taking to reduce mercury won't affect a pending legal challenge to the Bush Administration's rule. Sixteen states and a coalition of environmental groups are asking a federal court to jettison the Bush Administration's mercury rule and force EPA to issue a tougher regulation in its place. They argue that EPA went afoul of the Clean Air Act in creating a cap-and-trade program for a pollutant that is neurotoxic. Instead, they claim, EPA should require coal-fired power plants to install mercury control technology specified by the agency.
Becker says EPA's mercury rule shows how important it is for states to have the ability to regulate air pollution more stringently than does the federal government. He points out that some members of Congress, as part of legislation to curb releases of greenhouse gases, want to curtail states' ability to impose limits on air emissions that are tougher than federal standards.
Because of many states' actions to cut emissions of the metal faster and deeper, fewer people will be harmed by exposure to mercury than if all states merely adopted the weaker federal rule, Becker says. When EPA can't or won't make strong moves to protect the public from the risks of air pollution, he says, states will "do what's right for public health and the environment."
- Chemical & Engineering News
- ISSN 0009-2347
- Copyright © American Chemical Society