"The Impact of Ambient Air Quality Rules on Fossil-fueled Power Plants" was the Hot Topic Hour on December 15, 2011

The following three speakers discussed the challenges that will be faced by operators of fossil fueled power plants as a result of the new NAAQS for PM_2.5, SO₂, NO₂ and ozone and suggested actions to help utilities achieve compliance.

Bob Paine, Technical Director for Environment at AECOM, discussed the “Challenges for Modeling Compliance with Short-term NO₂ and PM_2.5 Ambient Standards."  Among the more significant challenges are:

§  Very low ambient standards for NO₂ and PM_2.5 are resulting in new nonattainment areas.

§  Emission limitations in these areas must be solved with dispersion modeling.

§  Modeling is also used for permitting new sources.

§  NO₂ modeled compliance is complicated by secondary formation of NO₂ from NO and a new, strict 1-hour standard.

§  PM_2.5 modeled compliance is complicated by high existing concentrations and secondary formation of PM_2.5 from SO₂ and NO_x emissions.

§  There are many conservative modeling approaches that lead to concentration over-predictions.

§  New Source Review permitting is very difficult with these new NAAQS and conservative modeling approaches.

He concluded that more realistic and unbiased modeling assessment methods are needed in light of tightening standards.

John Kinsman, a Senior Director and Environment and Air Issues Manager at the Edison Electric Institute (EEI), gave a very good overview of the compliance issues facing the Utility industry as a result of the NAAQS regulations as well as an overview of the status and attainment schedule for all regulations that can affect the stack emissions from power plants. He provided data to demonstrate that by 2016 after the MACT rules are implemented by utilities, emissions of PM _2.5 from utilities will be only 8 percent of the total man-made emissions from all sources, SO₂ will have been reduce by 92 percent from 1990 levels and NO_x will be down to two million tons from 6.7 million tons in 1990. In his opinion the Utility industry will have done way more than their share to reduce air pollution and that any further reductions must come from other sources.

He stated that the utility industry was still in limbo and listed the regulatory uncertainties that still face the industry:

§  Litigation

§  5-year reviews to reevaluate standard levels.

§  Designations – especially given new approach to using modeling for 1-hour SO₂ NAAQS.

§  State implementation plans (SIPs) to apportion necessary actions.

§  Regional EPA “transport rules” to address new PM and ozone NAAQS (following CSAPR and previous transport rules).

§  Cost/benefit

§  Attainability/background levels.

§  Implementation

§  Modeling – designations

§  Modeling – new sources

§  Offsets in non-attainment areas

§  Primary (health) vs. "secondary” (environment/welfare) standards.

Gale Hoffnagle, CCM, QEP, Air Quality Consulting Practice Leader at TRC Companies, Inc. discussed “Complying with the NAAQS for SO₂.”  He stated that the new short-term NAAQS (1 hour average) for SO₂ and NO_x as well as those for ozone, lead and PM_2.5 make existing and new sources subject to tremendous pressure on emissions. The new one hour SO₂ NAAQS is 7 to 10 times more restrictive than the prior NAAQS and very few sources can meet this NAAQS. He discussed challenges posed by the SO₂ NAAQS in detail and suggested the following actions for utilities to achieve compliance:

• Do their own modeling.

• Raise their stack height.

• Buy more land around the source.

• Increase plume height with more heat.

• Scrubbers to reduce SO₂ emissions may not help because the heat of the plume (and thus the plume rise) is reduced.

• Reduce fuel sulfur content.

• Monitor on your own to prove that your facility meets the NAAQS.

The Bios and Abstracts are linked below.

BIOS, ABSTRACTS, PHOTOS - December 15, 2011.htm