Cross-posted from the Natural Resources Defense Council.

Today, the EPA announced the most important actions to clean up air pollution from dirty coal-burning power plants since the Clean Air Act was last updated in 1990.

EPA’s proposed mercury and air toxics standards for power plants that burn coal and oil are projected to save as many as 17,000 American lives [PDF] every year by 2015. These standards also will prevent up to 120,000 cases of childhood asthma symptoms and there will be 11,000 fewer cases of acute bronchitis among children every year.

The standards also will avoid more than 12,000 emergency room and hospital visits and prevent 850,000 lost work days every year.

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The proposed standards should reduce mercury emissions from power plants burning coal and oil by 91 percent, acid gas pollution by 91 percent, direct particulate matter emissions by 30 percent, and sulfur dioxide (SO2) emissions by 53 percent, down to 2.1 million tons of annual SO2 emissions [PDF, pg. 541].

Due to these tremendous health benefits, the proposed standards are estimated to yield monetized benefits of $59 billion to $140 billion annually, compared to annual compliance costs of approximately $10.9 billion. This represents $5 to $13 in health benefits for every $1 spent to reduce pollution.

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Further, EPA projects that the proposed standards will create up to 31,000 short-term construction jobs and 9,000 long-term utility jobs.

More detailed information about the proposed air toxic standards may be found here.

Coming on the heels of an EPA report that projected the Clean Air Act will save approximately 4.2 million lives by 2020 even without the additional life savings from today’s proposal, the Clean Air Act has earned its place as America’s most successful environmental-public health law.

Yet in spite of these enormous public health benefits, industry naysayers have decried the power plant cleanup standards and may only increase those complaints in the coming days and weeks. Some utility industry lobbyists have complained that the expected standards will ask too much, too soon, and that coal-fired power plants already have taken great strides to reduce their air pollution.

So on the day that EPA’s long-anticipated mercury and air toxic standards are being proposed, before some of us pore through the materials that EPA has made available, I thought it would be useful to examine how we got here.

The following Q&A format is designed to address commonly raised issues surrounding why EPA is only now proposing these air toxics standards, some 21 years after the 1990 Clean Air Act amendments.

Q. How long has the Clean Air Act been used to clean up toxic air pollution, and when did Congress adopt the approach that EPA is following with today’s proposal?

A. EPA answers these questions nicely in its “Plain English Guide to the Clean Air Act“:

Before the 1990 Clean Air Act Amendments, EPA regulated air toxics one chemical at a time. This approach did not work well. Between 1970 and 1990, EPA established regulations for only seven pollutants. The 1990 Clean Air Act Amendments took a completely different approach to reducing toxic air pollutants. The Amendments required EPA to identify categories of industrial sources for 187 listed toxic air pollutants and to take steps to reduce pollution by requiring sources to install controls or change production processes. It makes good sense to regulate by categories of industries rather than one pollutant at a time, since many individual sources release more than one toxic chemical. Developing controls and process changes for industrial source categories can result in major reductions in releases of multiple pollutants at one time.

Q. What approach does the Clean Air Act use to reduce toxic air pollutants?

A. Again, quoting EPA’s guide to the Clean Air Act, “[t]he 1990 Clean Air Act requires EPA to first set regulations using a technology-based or performance-based approach to reduce toxic emissions from industrial sources.” This approach is called the Maximum Achievable Control Technology (MACT) program and requires performance standards to be based upon the emissions reductions achieved by the cleanest facilities in an industrial sector, the average of the top 12 percent of lowest emitting plants or equipment. As the agency’s guide explains, “in most cases, EPA does not prescribe a specific control technology, but sets a performance level based on a technology or other practices already used by the better-controlled and lower emitting sources in an industry.”

Q. How many toxic air pollution standards has EPA issued already under the 1990 Clean Air Act, and what types of industrial sources have been covered?

A. EPA has adopted over 120 toxic air pollutant standards under the act, covering literally hundreds of different types of industrial operations and equipment categories. These include chemical plants, oil refineries, hazardous waste incinerators, iron and steel foundries, battery manufacturers, pharmaceutical plants, lead smelters, semiconductor manufacturers, and fiberglass plants, among many others.

Q. Have other industries been reducing mercury emissions by levels comparable to what EPA is proposing power plants must achieve? If so, what pollution control devices have these other industries been using?

A. Yes. Many other types of industries have been reducing mercury emissions and many other toxic air pollutants under the Clean Air Act’s MACT program. For example, municipal and medical waste incinerators have been achieving 90 percent mercury reductions since the late 1990’s using a technology called activated carbon injection that many power plant operators also will employ to meet the proposed mercury standards.

Q. What toxic air pollutants do coal-burning and oil-burning power plants emit?

A. Power plants emit approximately six dozen toxic air pollutants [PDF] out of the 189 toxic air pollutants specifically listed for regulation in the Clean Air Act. These include mercury, arsenic, dioxins, lead, hydrochloric acid, chromium, nickel, and radionuclides.

Q. Why did EPA not start reducing toxic air pollutants from power plants after the 1990 Clean Air Act amendments when it started reducing those pollutants from other types of industries?

A. In 1992 EPA published a list of industrial categories for which it would develop toxic air pollution standards under the law’s new MACT program. NRDC filed suit against EPA alleging that the agency unlawfully omitted power plants from that list. Under the act, EPA was supposed to conduct a health effects study addressing whether the agency should regulate toxic air pollution from fossil fuel-fired power plants using MACT standards. The law requires such regulation if EPA determines that it is “appropriate and necessary.” As a result of the original lawsuit, NRDC and EPA entered into a settlement agreement in 1994, under which EPA was required to complete the study and report to Congress by November 1995. Following several delays, EPA submitted the report to Congress [PDF] in February 1998 — but still without making a determination about the appropriateness and necessity of MACT standards. Following notice of intent to file an “unreasonable delay” lawsuit by NRDC and the Sierra Club later in 1998, the original NRDC settlement agreement was modified twice more to require EPA to make the necessary regulatory determination by Dec. 15, 2000. Then-EPA Administrator Carol Browner did so and determined that it was “appropriate and necessary” to reduce toxic air pollutants from fossil fuel-fired power plants using the law’s protective MACT standards.

Q. So why did the Bush administration EPA not issue toxic air pollution standards for coal-fired and oil-fired power plants?

A. Soon after taking office, signs emerged that the Bush administration would not follow the law and issue the MACT standards for power plants required by the Clean Air Act. In a now-notorious April 2001 speech [PDF] that was recorded and transcribed without his awareness, a utility industry lobbyist told his coal industry audience that EPA had been planning to use the agency’s existing authority under the Clean Air Act to require large and prompt reductions in toxic air pollution from coal-burning power plants, namely MACT standards. Never fear, the lobbyist assured his colleagues, he and his friends in the Bush administration White House had a plan: the administration would create what the lobbyist called the “next generation of regulatory programs” for power plants. Predicting precisely what unfolded under the Bush administration, the lobbyist boasted that “the goal here will be to gain a foothold, an irreversible foothold on the next generation of reasonable cost effective SO2 and NOx reduction, plus air toxics that we can all live with and that someone else can’t undo.” Observing that “mercury is the killer,” the lobbyist signalled that eliminating the obligation to comply with MACT standards to reduce mercury and toxic air pollutants would be the very highest priority for the utility industry. And the Bush administration obliged that desire fully.

Q. So what did the Bush administration do instead?

A. In 2004, the Bush administration EPA issued rulemaking proposals that made clear it had no intention of following the law to require MACT standards that would reduce all toxic air pollutants from power plants. Then in early 2005, the administration confirmed that fear by retracting EPA’s prior commitment to protect public health by requiring MACT standards for toxic pollution from power plants, issuing a so-called “rescission rule”. Simultaneously, EPA issued a mercury “cap-and-trade” rule that purported to require significant reductions in power plant mercury emissions but in fact delayed any mercury regulation for 13 years. That rule disclaimed any need to reduce the remaining 70 or so toxic air pollutants from power plants and left power plants’ toxic air pollutants like arsenic, lead, dioxins, acid gases, and heavy metals completely unregulated.

Q. What happened to the Bush EPA mercury rule?

A. In February 2008, the U.S. Court of Appeals for the D.C. Circuit ruled [PDF] that EPA had illegally evaded the Clean Air Act’s protective safeguards — MACT standards — that should have required deep and timely reductions in toxic air pollution, including mercury, from the nation’s coal-fired power plants. The court further ruled that EPA had illegally substituted a mercury pollution trading scheme for the protections required by the Clean Air Act. The court vacated the EPA rules and made clear that EPA now had a firm legal obligation to adopt MACT standards to reduce all toxic air pollutants from power plants. The unanimous court ruling even went so far as to mock EPA’s defiance of the plain language of the law. The court compared EPA’s actions to the capricious Queen of Hearts in Alice in Wonderland, since EPA had — in the court’s words — “substituted [its] desires for the plain text” of the law. See my earlier post on this court ruling here.

Today’s proposed toxic air pollutants standards respond to that court decision and finally follow the law to require reductions in all toxic air pollutants from power plants for the first time since the 1990 Clean Air Act amendments.