Yesterday, the EPA released two proposals to regulate power plant emissions of mercury, one of the nastier pollutants. One is a command-and-control, technology standard of the sort favored by the Clinton EPA. The other is a market-based, “cap-and-trade” system favored by new EPA Administrator Leavitt (and, incidentally, an approach favored by the Clinton OMB). Whichever plan is adopted will represent the first ever legally binding restrictions on mercury emissions. (No, the Clinton Administration never got around to regulating mercury. They just laid out plans to do so in the future.) For more on EPA’s recent actions, see here.