The Supreme Court case that’s likely to handcuff the Clean Water Act

For decades, the Supreme Court struggled to define a key term at the heart of the Clean Water Act, the landmark 1972 legislation that forms the backbone of America’s efforts to “restore and maintain the chemical, physical, and biological integrity of the Nation’s waters.”

It’s an admittedly difficult question, that is now in the hands of the most conservative Supreme Court since the 1930s. And the Court’s Republican-appointed supermajority seems poised to deal a severe blow to the clean water law, in a case that could do significant harm to America’s efforts to prevent floods and to ensure that everyone in the country has access to safe drinking water.

The Clean Water Act prohibits “discharge of pollutants” into “navigable waters.” But it also defines the term “navigable waters” vaguely and counterintuitively, to include all “waters of the United States, including the territorial seas.” In Rapanos v. United States (2006), the Supreme Court’s last attempt to define the key phrase “waters of the United States,” the justices split three ways, with no one approach winning majority approval from the Court.

Now, Sackett v. EPA brings this question to a Court that’s moved dramatically to the right after former President Donald Trump filled a third of its seats. Though the specific dispute in Sackett seems minor — it involves a couple that wants to fill in wetlands on their residential lot near an Idaho lake — the case still gives the Supreme Court everything it needs to hamstring much of the landmark anti-pollution legislation.