Particulate Matter

Most Recent Action

In response to a court order, the EPA has finalized the first update to the national air quality standards (NAAQS) for fine particle pollution (PM2.5), including soot, in 15 years. The agency is setting the annual health standard, also known as the primary standard, at 12 micrograms per cubic meter, a 20 percent reduction from the current limit of 15 micrograms per cubic meter. The new standard goes into effect on March 18, 2013.

 

Background

The EPA originally set air quality standards for particulate matter in 1971 and they were not significantly revised until 1987, when the EPA changed the standards to regulate inhalable particles smaller than, or equal to, 10 micrometers in diameter (which is about one-fourth the size of a single grain of table salt).

Ten years later, in 1997, the EPA revised the PM standards, setting separate standards for fine particles (PM 2.5). The EPA last revised the air quality standards for particle pollution (PM) in 2006. The EPA strengthened the 24-hour fine particle standard (PM2.5) by lowering the level to 35 micrograms per cubic meter (µg/m3), and retained the existing annual fine particle standard of 15 µg/m3. The EPA retained the existing 24-hour PM10 standard of 150 µg/m3. The agency revoked the annual coarse particle standard (PM10), citing the lack of evidence suggesting a link between long-term exposure to PM10 and health problems.

On February 24, 2009, the United States Court of Appeals struck down the EPA’s PM2.5 primary annual standard of 15 micrograms per cubic meter (µg/m3) and remanded for reconsideration. The court ruled that the EPA “did not adequately explain why an annual level of 15µg/m3 is sufficient to protect public health while providing an adequate margin of safety from short-term exposures and from morbidity affecting vulnerable subpopulations.” Because 2006 standards were remanded, not vacated, they remained in effect while new standards were promulgated.

The EPA missed the October 2011 statutory deadline to complete review of the current NAAQS for particulate matter within the applicable 5-year period. A lawsuit was filed by states and environmental groups in the U.S. District Court for the District of Columbia in February of 2012, alleging that EPA failed to perform its mandatory duty to revise the NAAQS for PM2.5. The district court ordered EPA to sign a proposed rule setting the NAAQS by June 14, 2012 and finalize standards by December 14, 2012. The EPA was able to meet those deadlines.

This rule is part of a group of rules known as the EPA’s Regulatory Train Wreck.

 

Authority

42 USC Sec. 7409 (CAA) – National Primary and Secondary Ambient Air Quality Standards: December 31, 1970. This section of the CAA provides the EPA authority to promulgate National Ambient Air Quality Standards (Primary and Secondary) or, NAAQS.

 

Standard

The agency is setting the annual health standard, also known as the primary standard, at 12 micrograms per cubic meter, a 20 percent reduction from the current limit of 15 micrograms per cubic meter.

The new standard does not change the existing primary 24-hour standard for fine particles, currently 35 μg/m3, or the existing daily standard for coarse particles (PM10), currently 150 μg/m3, which includes dust from farms and other sources.

The final rule differs from the rule proposed in June 2012 in that it does not change the existing secondary standards for PM2.5 to address PM-related effects such as visibility impairment, ecological effects, damage to materials and climate impacts. The secondary standards remain 15.0 μg/m3 (annual) and 35 μg/m3 (24-hour).

The EPA is projecting that all but 66 counties, out 3,033 counties in the United States, will be able to meet the new standard through their compliance with other EPA pollution rules. Therefore the cost of this rule is estimated at only $53 million to $350 million, which does not include the cost of implementing the other regulations which will be responsible for most of the PM reductions.

The EPA anticipates making initial attainment/nonattainment designations by December 2014, with those designations likely becoming effective in early 2015. It is expected that fewer than 10 counties will need to consider any local actions to reduce fine particle pollution in order to meet the new standard by 2020 (because reductions from other rules will allow counties to meet the standards).

States would have until 2020, five years after designations are effective, to meet the revised annual PM2.5 health standard. By 2020, all but seven counties, all in California, are projected to meet revised health standard without any additional actions.

The new rule also addresses several issues related to implementation of the revised standards. To ensure a smooth transition to the revised standards, the EPA will grandfather pending preconstruction permitting applications if either the permitting agency has deemed the application complete by December 14, 2012 or the public notice for a draft permit or preliminary determination has been published prior to the date the revised PM standards become effective (60 days after publication in the Federal Register).

The agency is making updates and improvements to the nation’s PM2.5 monitoring network that include relocating a small number of monitors to measure fine particles near heavily traveled roads in areas with populations of 1 million or more. These relocations will be phased in over two years (2015-2017) and will not require additional monitors.

In addition, the EPA is updating the Air Quality Index (AQI) for PM2.5 to be consistent with the final health standards.

 

Related Documents

The EPA’s PM Website

2012 Court-Ordered Standard:

Final Rule, January 15, 2013

Press release

Overview Fact Sheet

Fact Sheet: Health

Fact Sheet: Standards and Air Quality Index

Fact Sheet: Implementing the Standards

Regulatory Impact Analysis

Tables and Maps

EPA Projections Show 99 percent of U.S. Counties With Monitors Would Meet the Annual Fine Particle Health Standard of 12.0 µg/m3 in 2020

Most Of The U.S. Already Meets the Annual Fine Particle Health Standard of 12.0 µg/m3

Projected Fine Particle Concentrations in 2020 for Counties with Monitors

Fine Particle Concentrations Based on Monitored Air Quality 2009 – 2011

Proposed Rule, June 29, 2012

Correction, June 29, 2012

Hearings – July 17 and 19, 2012

Overview Fact Sheet

Fact Sheet: Health

Fact Sheet: Standards and Air Quality Index

Fact Sheet: Implementing the Standards

How to Comment– Due August 31, 2012

Tables and Maps

EPA Projections Show Virtually All Counties Would Meet the Proposed Primary Fine Particle Standards in 2020

Monitoring Data Show Few Additional Counties Would Not Meet Proposed Primary Fine Particle Standards

Monitoring Data Show Few Counties Would Not Meet Proposed Secondary Fine Particle Standards

EPA Projections Show Virtually All Counties Would Meet the Proposed Secondary Fine Particle Standards in 2020

Projected Fine Particle Concentrations in 2020 for Counties with Monitors

Fine Particle Concentrations Based on Monitored Air Quality 2008 – 2010

Visibility Index Based on Monitored Air Quality from 2008 – 2010

Projected Visibility Index in 2020 for Counties with Monitors

Technical Support Documents

EPA’s Policy Assessment for the PM NAAQS Review

EPA’s Risk and Exposure Assessment for the PM NAAQS Review

EPA’s Science Assessment

Clean Air Scientific Advisory Committee (CASAC) Review

Additional information for the PM NAAQS review

Increments, Significant Impact Levels (SILs), and Significant Monitoring Concentration (SMC) for Prevention of Significant Deterioration for Particulate Matter less than 2.5 Micrometers (PM2.5), October 20, 2010.

Comments are closed.