On March 27, 2012, the U.S. Environmental Protection Agency (EPA) released its proposal to regulate greenhouse gases emitted from newly constructed fossil-fueled (e.g. coal, natural gas) power plants. Known as the greenhouse gas New Source Performance Standards (NSPS) for power plants, the rule proposal places limits on the amount of greenhouse gases that a new fossil-fueled power plant can emit. The pre-publication version of the rule proposal is available here.

It is fair to say that the approach taken by EPA in this rulemaking is unprecedented. The structure of the Clean Air Act has led EPA to historically propose emission limits by source category or subcategory. For example, in the power industry, what this has meant is that EPA has looked at the best performing, or group of performing, coal-fired power plants and has set limits for all coal-fired power plants based on that standard of performance; EPA has looked at the best performing, or group of performing, gas-fired power plants and has set limits for all gas-fired power plants based on that standard of performance; and so on. This structure and precedent has ensured that EPA stayed within their legal role of making technical determinations to reduce emissions at sources, while not making sweeping energy policy and fuel choices for the entire country – a role strictly reserved for Congress and the states.