PM2.5

The U.S. Environmental Protection Agency (EPA) in February issued a final rule imposing tighter restrictions on fine particulate matter (PM2.5) or soot.  The final rule, issued on Feb. 7, strengthens the nation’s National Ambient Air Quality Standards (NAAQS) by lowering the level of the primary (health-based) annual PM2.5 standard from 12.0 micrograms per cubic meter […]

In a significant but controversial final action, the Environmental Protection Agency (EPA) on Dec. 7 retained its existing National Ambient Air Quality Standards (NAAQS) for both fine and coarse particulate matter (PM2.5 and PM10). While the EPA said the decision came “after careful review and consideration of the most recent available scientific evidence and technical […]

Residents of Texas living downwind of coal-fired power plants would be far better off today if regulators had focused on cutting particle-forming SO2 emissions rather than concentrating so keenly on ozone-causing emissions, according to a recent study conducted by researchers at Rice University in Houston, Texas. The head of the study, environmental engineer Daniel Cohan, […]

The world’s power sector last year emitted a third of global sulfur dioxide (SO2) emissions, 14% of nitrogen oxides (NOx), and 5% of total particulate emissions (PM2.5), but those emission values have fallen drastically over the last decade even though coal power generation has seen a surge, the International Energy Agency (IEA) said in a […]

This is an online supplement to the feature story “The  Need for Alternate PM2.5 Emission Factors for Gas-Fired Combustion Units” in the July 2015 issue of POWER. The history of in-stack PM measurement methods began in 1971 with promulgation of the U.S. Environmental Protection Agency (EPA) Reference Method 5, following on the heels of promulgation […]

The Environmental Protection Agency’s emission factor resource, AP-42, is not your only option for developing particulate matter (PM) emission rates. Results of a prominent PM emissions measurement research program for gas-fired plants have been successfully used to support development and application of alternate PM2.5 emission factors by both regulatory agencies and permit applicants The regulatory […]

A three-judge panel of the U.S. Court of Appeals for the District of Columbia last week upheld the Environmental Protection Agency’s (EPA’s) primary National Ambient Air Quality Standards (NAAQS) for fine particulate matter (PM2.5), dispensing to the agency its third major legal victory on air pollution in a month. The EPA in December 2012 issued […]