The EPA was supposed to revisit their standards for ground-level ozone, currently 76 parts per billion (ppb) over a three year average, some years ago but for one reason or another have continued to put the decision off. It has long been known that the EPA is likely to adjust the standards down to within a range of 60 to 70 ppb.
U.S. District Judge Yvonne Gonzalez Rogers on Tuesday directed the EPA to issue its draft proposal by Dec. 1, 2014, and a final rule by Oct. 1, 2015.
The decision comes after a lengthy scuffle over the ozone rules dating back to the George W. Bush administration. In March 2008, the Bush EPA adopted new standards that limited the acceptable amount of ozone in the air to 75 parts per billion. But those standards were weaker than the agency’s own scientists had advised. And when the Obama administration came into office, then-EPA Administrator Lisa Jackson said the 2008 standards were “not legally defensible.”
Roanoke is still in attainment if the standard is set in the upper part of the 60 to 70 ppb range. Much lower than 65 ppb and the standard becomes problematic, not just for Roanoke but for many regions. While the measure may, indeed, indicate a less-than-healthy concentration of ozone, a standard that low may overlap background ozone levels that might affect a region even if no pollution activity was taking place. In the Roanoke Valley, the presence of I-81 and some nearby coal-fired power plants generate a significant portion of our ozone precursors and yet are out of our control. This could result in businesses and local governments suffering regulatory action for pollution sources cited elsewhere, burdening the localities while having no material affect on pollution.
However, a much lower standard could heighten the need to deal with sources on the macro level – tightening pollution controls for power plants and large industries whose impacts are far beyond their local borders. It’s believed, for example, that a contributor to the improvements Roanoke has seen in the last few years has been a transition to cleaner-burning diesel engines, meaning all that truck traffic on I-81 hasn’t been polluting as much. If the standard is set lower and coordinated with stronger federal or state action, and fewer penalties at the local level, it could be a significant win for cleaner air in southwest Virginia.