摘要：As oil and gas development increases in western states, states are responding at different speeds to protect human health and the environment. Colorado and Wyoming are recognized as having taken relatively early action to regulate air pollution emissions from oil and gas development, with Wyoming adopting its first sector-specific requirements in 1999. In contrast, New Mexico and Utah have been relatively slow to act. Furthermore, the U.S. Environmental Protec tion Agency did not adopt emissions standards for most oil and gas production activities until 2012, when it relied on Colorado and Wyoming as proving grounds for control technology. The regulatory history in these four western states shows that concern about ozone nonattainment was an important driver for control requirements in Colorado and Wyoming. These two states also have a history of relatively stringent pre-construction permitting requirements for small sources. In some areas, National Environmental Policy Act requirements for cumulative impact assessment drove adoption of tighter controls to mitigate impacts of growth. Moving forward, federal emissions standards will even out control requirements for new sources across the western states. However, con trol efforts that go beyond the 2012 federal standards will likely be needed in ozone nonattainment areas in western Wyoming, northeastern Utah, Colorado’s Front Range, and in Indian Country. Further efforts will also be needed to ad dress greenhouse gas emissions including methane.
