Air Toxics

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EPA’s standards for hazardous air pollutant (HAP) emissions from industrial boilers have been controversial for nearly two decades. Ever since EPA first proposed “maximum achievable control technology” (MACT) standards for boilers in 2003, which were then entirely vacated by the D.C. Circuit, each new iteration of the rule has raised new legal issues and often foundered in court.

On May 5, 2020, the Illinois Attorney General filed a complaint against a developer and its contractors responsible for demolishing the smokestack of a former coal-fired power plant in Chicago. The suit provides a good reminder that careful planning for the control of fugitive dust emissions is critical during decommissioning activities—and that state legal offices and regulators will keep their eyes on potential environmental issues at coal-fired plants until the last brick comes down.

On March 9, 2020, EPA published its final “risk and technology review” for the standards it adopted in 2004 to regulate emissions of hazardous air pollutant (HAP) from natural gas-fired combustion turbines. Like most other such reviews, EPA confirmed that the risks presented by HAP emissions from the source category are acceptable with an ample margin of safety. EPA also concluded that there are no new cost-effective controls for reducing those emissions.

The Environmental Protection Agency (EPA) has proposed to expand the applicability of the National Emission Standards for Hazardous Air Pollutants (NESHAP) for stationary combustion turbines. EPA originally established the combustion turbine (CT) NESHAP in 2004. On April 12, EPA officially proposed the long overdue residual risk and technology review (RTR), which is required within eight years of the final standards.

While, based on its RTR analysis, EPA proposes to leave the current CT standards in place, the proposal would expand the reach of those standards to two additional subcategories of units by lifting a stay that has been in effect since the standards were originally finalized. Lifting that 15-year-old stay would impact lean pre-mix and diffusion flame natural-gas-fired CTs. The proposal would also eliminate the startup, shutdown, and malfunction exemption for all units subject to the rule. Although all existing lean pre-mix and diffusion-flame gas-fired units would become subject to the NESHAP, only units constructed or reconstructed after January 14, 2003 must comply with substantive emission and operating limitations.

On February 7, 2019, EPA published its proposed revised Supplemental Cost Finding for the Mercury and Air Toxics Standards (MATS) and risk and technology review. The proposal re-evaluates the cost of complying with the MATS rule for coal- and oil-fired power plants, and the associated benefits of regulating hazardous air pollutant (HAP) emissions from these sources. Based on its revised analysis, EPA has determined that it is not “appropriate and necessary” to regulate HAP emissions from power plants under Section 112 of the Clean Air Act.

In the last month of 2018, EPA released two proposals that it claims will have no immediate effect—revised CO2 standards for new coal-fired power plants that EPA does not expect anyone to build, and a determination that it is not “appropriate and necessary” to have a mercury rule that it nevertheless plans to keep on the books.  The question many may be asking is why EPA would issue two highly controversial rules if they won’t have any practical effect?  The answer may lie in the precedent they will set.

On December 28, 2018, the U.S. Environmental Protection Agency (“EPA”) released a pre-publication version of a proposal revisiting the cost analysis underlying the Mercury and Air Toxics Standards (“MATS Rule”) for coal- and oil-fired electric generating units (EGUs) and conducting the residual risk and technology review required by the Clean Air Act (“Proposal”).  The Proposal would reverse a previous finding, issued by EPA under the Obama Administration, that regulation of hazardous air pollutant (“HAP”) emissions from EGUs under the MATS Rule was “appropriate and necessary” but would nonetheless leave the rule in effect.  The Proposal also concludes that more stringent HAP emission limits are not warranted by the required risk and technology reviews.