(AP) — The Harpeth River Watershed Association has filed a federal lawsuit against the city of Franklin over its wastewater treatment plant. "The Harpeth is one of the unique freshwater river systems in the Southeast, but unfortunately we have reached a critical point where this sewage discharge threatens the health of the river, especially during the summer months, when the river is naturally a low-flowing river and already experiencing poor water quality caused by upstream sources," said Dorie Bolze, HRWA executive director, in a statement. City officials haven't responded to the lawsuit, but have defended the plant, saying in a statement that the group's claims are "exaggerations and misunderstanding of the regulatory requirements."