I don't even know why I'm surprised by this

I was reading some articles for work about Mercury Polution and reduction required by power plants, and came across the Bush Administration's Mercury Rule of 2005 which aims to reduce Mercury emissions substantially by 2010. However, the law allows utilities to either lower their Mercury emissions OR purchase credits from other plants that have made more drastic cuts. This system is the cheapest and fastest way to reduce Mercury emissions... without actually doing any widespread reducing.