"We just felt that we could and should do more than EPA was asking on mercury," says Dean Van Orden, chief of the air information division of Pennsylvania's air-quality bureau. "We think it's significant so many other states are doing the same thing, including coal-producing states."
Pennsylvania's plan would cut mercury emissions 80 percent by 2010 in a first phase and 90 percent by 2015. By contrast, CAMR cuts 21 percent of mercury nationwide by 2010 and 70 percent by 2018. With costs of mercury-control technology falling sharply, tougher regulations were the right thing to do, some state officials say.
Pennsylvania and others are also not participating in emissions trading. While "cap and trade" systems worked for sulfur dioxide and other pollutants, many states argue that mercury is different because it is a toxin rather than a mere pollutant. Already, more than 3,200 health advisories warning of mercury contamination in fish from streams and lakes have been issued in 48 states.
And because mercury particles can begin dropping out of the air just a few miles from where they're emitted, state officials worry the trading system might create new mercury "hot spots" within their borders.
Illinois is another state taking a pass on CAMR, even though it's a major coal- producing state. "We are not doing CAMR or mercury trading – no trading," says Jim Ross, manager of the Illinois EPA's division of air-pollution control. "We have proposed our own mercury rule that requires greater reduction and is much faster than the federal rule."
US EPA officials say that states opting out of CAMR is no surprise.
"We always knew many states would want to do something different and that's fine," says Mr. Wehrum. "We also knew many would choose CAMR as a smart way to regulate that's economically efficient and easy to administrate."