On Jan. 3, EPA published a proposed rule potentially allowing "major source" air pollutant emitters to be downgraded to "area source" emitters. Major sources are subject to maximum achievable control technology (MACT), which often results in a significant reduction in air pollution. Area sources are not subject to the MACT standard. Under the current rules, major sources retain that designation permanently — a policy EPA refers to as "once-in, always-in." The proposed rule would repeal the current policy. Environmentalists have criticized the rule for being too lenient on big polluters. Yesterday, the House took action. The bill appropriating funds to EPA includes language which would forbid EPA from using money to implement the rule, according to BNA news service (subscription). The bill passed the House and will soon be reconciled with the Senate version. The bill will likely be vetoed by President Bush for exceeding his budget request. Regardless, this is an interesting case example of Congress's ability to use its power of the purse to counter the administration's deregulatory actions. It's a strategy Democrats should continue to examine during the remainder of Bush's second term.