Lead air quality review should wait for current data

April 28, 2011

The Environmental Protection Agency shouldn’t decide whether to change the air quality standards for lead until it can evaluate data from the most recent tightening of requirements, the General Aviation Avgas Coalition told the agency April 28.

The EPA requested comments on a draft integrated review plan for the National Ambient Air Quality Standards (NAAQS) for lead. But monitoring stations are still being implemented to evaluate the effects of the last change to the standards, a tenfold reduction in lead levels that took effect in 2009. The coalition called for the EPA either to determine that a revision of the standard is not appropriate or to extend the assessment phases of the review to evaluate the more recent data. The GA Avgas Coalition, which includes AOPA, is working toward a viable transition to an unleaded avgas for piston aircraft.

The Clean Air Act requires a periodic review of air quality standards and, if appropriate, revisions of the criteria. The first revision to the 1978 standard came with the dramatic reduction published in 2008, which took effect the following year: from 1.5 micrograms/cubic meter to 0.15 micrograms/cubic meter. The revision may have a significant impact on lead emissions, exposure, and any related risk analysis, the coalition said, and the review timeline should allow for consideration of the recent change’s effects.

That revision also required extensive monitoring, reporting, and modeling of lead levels at locations around the country; other requirements, including monitoring at 15 specific airports, were added in 2010. Many sites from this new monitoring network will not have a year’s worth of data until 2013, the coalition wrote.

“Because implementation of the 2008 lead NAAQS could result in significant reductions in lead emissions, revising the lead NAAQS is premature until the impact of those changes can be realized, measured, and considered in the next NAAQS review,” the coalition wrote, urging the EPA to consider new and valuable lead monitoring data in its review.

The GA Avgas Coalition comprises AOPA, the American Petroleum Institute (API), the Experimental Aircraft Association (EAA), the General Aviation Manufacturers Association (GAMA), the National Air Transportation Association (NATA), the National Business Aviation Association (NBAA), and the National Petrochemical and Refiners Association (NPRA). The groups came together to ensure that a continuous supply of the existing aviation fuel is available, assuring the utility of the piston-engine fleet; establishing a process that, working with the FAA, develops and implements a comprehensive program to facilitate the qualification of an unleaded avgas replacement for 100LL; and establishing a timeline that allows adequate time for transitioning to an unleaded solution.