Owners of property covered by wetlands near Priest Lake, Idaho, a navigable body of water, as well as one of its non-navigable tributaries, sought to fill the wetlands without obtaining a permit under the Clean Water Act. They then brought a lawsuit challenging a determination by the EPA that the wetlands on the property are within the scope of the Act’s requirement that a permit be obtained for any discharge of pollutants to the “waters of the United States.” They advocated a restrictive reading of the term “waters of the United States” and invoked isolated uses of that phrase in an 1899 statute that, they asserted, control its meaning more than 70 years later in the Clean Water Act. They based their argument in large part on the interpretive maxim that when statutory language is “transplanted” from one statute to another, it carries with it the meaning from the earlier statute.
In the Supreme Court, Public Citizen filed an amicus brief supporting EPA. The brief explains that the interpretive principle on which the petitioners rely applies only to language that had a well-settled meaning in an earlier statute, and even then does not apply if the context of the new statute, including its language and stated purposes, reveals a different meaning. Here, the phrase “waters of the United States” in the 1899 statute did not have a settled meaning, let alone the one advocated by the petitioners. Moreover, the Clean Water Act, unlike the 1899 law, is explicitly aimed at protecting the chemical and biological integrity of the nation’s waters, not just their capacity for navigation; the Act’s language and context thus foreclose limiting the meaning of the phrase to navigable waters, regardless of the 1899 statute.