New EPA Clean Air Act Regulations

The U.S. EPA adopted new national ambient air quality standards (NAAQS) for PM2.5, fine particulates with a diameter of 2.5 microns or less, on Dec. 14. PM2.5 has both an annual and a 24-hour standard. The annual standard was lowered from 15 micrograms per cubic meter (ug/m3) to 12 ug/m3, which is the lower end of the range that had been proposed by EPA in June. EPA is not proposing to change the 24-hour PM2.5 standard, which is set at 35 ug/m3. 

States must now determine whether any areas within their jurisdiction are out of attainment with the new PM2.5 annual standard. The state’s determination must be submitted to EPA by December, and the EPA will have one year to issue its final determinations as to what portions of any states are not meeting the standards.

There are a couple of unique features about this new rule. First, EPA is grandfathering Prevention of Significant Deterioration permit applications that were deemed complete by Dec. 14. This new approach protects sources that have already entered the PSD permitting process from having to revise their application now that the standards have been issued.

Additionally, EPA chose not to adopt a new PM2.5 secondary standard that was intended to specifically address visibility impacts. The June proposal would have adopted a 24-hour visibility standard of between 28 and 30 deciviews to address PM-related visibility impairment. 

Secondary standards are intended to protect public welfare, including ecological impacts and visibility, while primary standards are intended to protect public health. This was the first time that EPA proposed to adopt a distinct visibility standard, and it was controversial. Ultimately, however, the agency concluded not to adopt a visibility standard, but instead to retain the current secondary PM standards with the notion that the concentration-based standards would be an adequate surrogate for visibility protection. 

Boiler MACT and CISWI
On Dec. 20, the EPA signed amendments to the Boiler Maximum Achievable Control Technology standards, originally issued in March 2011. In order to determine how these rules might affect a biomass boiler, it is necessary to determine whether the boiler is located at an area or a major source of Hazardous Air Pollutants.  A major source is a facility that has the potential to emit 10 or more tons per year of any individual HAP, or 25 or more tons per year of aggregate HAP. Under both the 2011 rules and the new rules, existing biomass boilers at area sources are not subject to emission standards, but are subject to work practices. New biomass boilers at area sources are subject to both emission standards and work practices, but the 2012 rule amendments loosen the work practices and revise the emission standards for biomass boilers.

The most dramatic rule changes came in relation to biomass boilers at major HAP sources. Both existing and new biomass boilers at major HAP sources are subject to emission and work practice standards, and many of the emission standards got more stringent as a result of the December revisions. However, boilers at major sources now have an additional three years to come into compliance, by Jan. 31, 2016.

In a separate but related action, EPA revised the nonhazardous secondary materials rule (NHSM). This rule defines which materials are “solid waste” when burned in combustion units. Boilers that burn solid waste are considered commercial and industrial solid waste incinerators, and are required to meet extremely stringent standards. If possible, sources want to avoid becoming regulated as CISWIs.

The December revisions to the NHSM Rule were good for the biomass industry. Further clarification was given as to those fuels considered “clean cellulosic biomass,” and so presumptively not solid waste. In addition, the rule clarified the nonwaste status of resinated wood, landfill gas, and pulp and paper sludge. Hope was raised that relief for construction and demolition wood, as well as paper recycling residuals, was not far behind. EPA suggested that it might even clear the way for railroad ties to be considered fuel, however, regulatory relief for these three fuels requires further rulemaking.

Authors: Thomas Wood
Attorney, Stoel Rives
503-294-9396
[email protected]

Kevin D. Johnson
Attorney, Stoel Rives
612-373-8803
[email protected]