EPA Decides to Retain 2010 SO2 NAAQS

From OMA Connections Partner Dinsmore: “On February 26, 2019, EPA announced its decision to retain the current sulfur dioxide (SO₂) National Ambient Air Quality Standard (NAAQS). The current primary SO₂ NAAQS of 75 parts per billion (ppb) averaged over one hour was established in 2010. …

“Several industry groups asserted that the current SO₂ NAAQS was too tough and argued that EPA should weaken the standard. They recommended that EPA raise the NAAQS to 110 – 150 ppb, but environmental groups argued the standard was not protective enough of human health and should be lowered to 50 ppb. Ultimately, EPA rejected both arguments and determined the current standard “is requisite to protect public health, with an adequate margin of safety, from effects of SO₂ in ambient air.” It noted that this was consistent with the April 2018 recommendation of the Clean Air Scientific Advisory Committee, an independent advisory board. EPA also supported its decision by reiterating that SO₂ levels in the United States had dropped by more than 85 percent between 1990 and 2017 and more than 60 percent since 2010.

“As a result of this decision, revisions to state implementation plans will not be triggered, and existing sources will not face potential imposition of requirements for installation of additional controls for SO₂. However, the one-hour standard remains a potential barrier to permitting new projects with significant SO₂ emissions.”