The Ogeechee Riverkeeper is suing state environmental officials.
The suit against the Environmental Protection Division alleges the agency kept the public in the dark following the largest fish kill in Georgia history.
After the fish kill soiled the southeast Georgia river in May, EPD traced its probable source to a textile plant.
Instead of imposing a fine, the agency agreed to let Screven County's King America Finishing fund $1 million worth of unspecific river improvement projects.
Riverkeeper Dianna Wedincamp says, the deal was a "slap on the wrist" and the public had a right to comment on it.
"Our biggest issue since the beginning has been the lack of communication between the officials who are supposed to protect the public health and the public," Wedincamp says. "Being that this was the largest fish kill in Georgia history and that so many citizens were affecte by this, this should have been one of those instances where the people were involved."
An EPD spokesman declined to comment, citing ongoing litigation.
The Riverkeeper filed suit to stop the agreement in an administrative law court.