Environmental groups allege a southwestern Montana water district is illegally polluting the West Fork of the Gallatin River.
On Wednesday, the groups sent a 60-day notice of intent to sue the Big Sky County Water and Sewer District for violation of the federal Clean Water Act.
The Cottonwood Environmental Law Center, Gallatin Wildlife Association, and Montana Rivers wrote in their letter that a wastewater pond near the Big Sky ski resort is leaking pollutants without a permit into the Gallatin River.
Cottonwood Environmental Law Center executive director and lawyer John Meyer says the filing doesn’t necessarily mean the groups will sue.