NASHVILLE (AP) - The city of Franklin has agreed to take steps to limit pollution of the Harpeth River from its sewage treatment plant.

The settlement between Franklin and the Harpeth River Watershed Association was filed in federal court on Tuesday. It calls for Franklin to add pollution controls as it expands its sewage plant. Franklin also has agreed to spend $10 million over five years on upgrading old sewer lines and other projects to protect the river as part of its capital improvements budget.

As part of the settlement, Franklin has agreed to notify the public about sewage spills through its website and also by placing signs near affected streams and notifying nearby residents and businesses.

Watershed Association Executive Director Dorie Bolze said in a phone interview that step will help build public support for spending money to maintain and improve the sewage system.

Franklin also has agreed to perform extensive water quality testing as part of a comprehensive study of the entire Harpeth River watershed. Bolze said the study will be done in conjunction with the U.S. Environmental Protection Association and will be a demonstration project for the Southeast.

"Figuring out what's going on in the river is a big deal," Bolze said.

Bolze said it's important to study the entire watershed to know where pollution is coming from and where it is going.

"Impacts can happen 20 or 30 river-miles downstream," she said.

Franklin has committed up to $150,000 for its part of the project.

The settlement comes after an acrimonious fight between Franklin and the nonprofit. That included a countersuit in which the city likened the nonprofit's Clean Water Act suit to extortion.

U.S. District Judge Kevin Sharp in November dismissed the city's claim and encouraged the parties to have some "adult conversation" to resolve their differences.

Sharp must sign the settlement be fore it becomes final. The settlement will be enforceable by the court.

Neither party has admitted any wrongdoing and neither will seek attorneys' fees.