We still have a lot of work to do, but there is no doubt that our water is safer to fish from and cleaner to swim in than it was when Congress passed this law. Yet even as we continue to make progress, it is time for another transformative change.

This law has given the nation the tools needed to begin cleaning up the nation's increasingly contaminated waters, and it has proven to be one of the most important, effective, and highly regarded environment laws in the world.

The Clean Water Act turns 40 today. As many know, a 40th birthday can be a momentous occasion for some, an "it's all downhill" moment for others, and just another year for the indifferent.

Nothing is more essential to our health, economy, and quality of life than clean water. In the face of a changing climate and ongoing threats from Congress, it is more important than ever to stand strong for clean water.

From Mother Nature Network's Russell McLendon: 1972 was a watershed year for American water. That fall, an unusually unified Congress overrode Pres...