The moment we’ve all been waiting for has arrived. The Roberts Court, with freshly added Justice Alito, will hear two cases this week on the Clean Water Act. The two new justices will have their first chance to grapple with the Constitution’s Commerce Clause, upon which much federal environmental law rests, from the highest bench in the land. I’m no lawyer, so I can’t really write anything about the intricacies of the Commerce Clause. The Center for American Progress did host three constitutional lawyers last year, and their remarks might be helpful. One was Doug Kendall, who is representing state officials that want the continued help of the feds because they “cannot adequately protect these resources acting alone.”

One key issue even this non-lawyer can understand is the disconnect between the Clean Water Act’s regulation of “navigable waters” and Congressional intent and the public’s desire to have a federal level of protection for water in the United States. Back in 2001, the Supreme Court ruled that the Army Corps overreached its authority by claiming control over an isolated quarry in Illinois. Acccording to the New York Times story,

The court ruled that there had to be a “significant” nexus between the regulated wetland or stream and true “navigable waters.” If not, regulation of the water body fell to the state.

At that point, the Bush administration’s Army Corp moved to change its regulation. This change was beaten back by one of the first (and sadly few) instances of the “hook and bullet” crowd teaming up with environmental groups to stop detrimental regulation changes. They got 218 Members of Congress to send a letter requesting that the regulations not be changed. (218 is the magic number needed to pass a bill in the House of Representatives.) Army Corps pulled back its proposal, and I think it has been in limbo ever since.

Recognizing a problem in the law, bipartisan groups of Congressfolk have introduced bills that would change the protected waters in the Clean Water Act from “navigable waters” to the “waters of the United States.” Neither bill has received a committee hearing yet. And I’m not holding my breath.

And now the newly realigned Supreme Court will have a chance to weigh in.

What’s at stake? The fate of half of currently protected waterways, or even 99 percent by one estimate. Stay tuned.