As mentioned in an article here, the return of the Toxic Release Inventory's Form A to its older reporting levels -- back to 500 pounds instead of 2000 pounds of releases, if you don't want to get technical about it -- was attached to the spending bill and signed into law. It was pretty much a race between the judicial, legislative, and executive branches to see who would get this one first after Bush left.
If you do want to get technical about it, then this particular Post article, like almost all news articles that I know something about, is misleading. A sentence reads "The legislation restores the standard established by law in 1986, compelling all facilities to inform the public of any chemical releases that total 500 pounds a year or more, lowering the 2,000-pound threshold Bush had adopted." I could see not mentioning that it was actually two thresholds that were affected (one for releases and the other for waste generated). But the standard was never set by law, in 1986 or anytime else. The law leaves it up to EPA to set a reasonable standard. That's why the threshold can change in the first place. The older Form A level, which is what we're returning to, didn't even exist at all within the law as passed in 1986 -- it was added to TRI for 1995.