Exclusive: Franklin will increase wastewater into the Harpeth River

Show Caption Hide Caption Video: Heavy rain raises level of Harpeth River Heavy rains caused the Harpeth River to rise on Sunday, April 22, 2017.

The Tennessee Department of Environment and Conservation approved a new permit on Thursday to allow the city of Franklin to increase its wastewater discharge into the Harpeth River.

TDEC issued a National Pollutant Discharge Elimination System (NPDES) permit regulating discharge from the Franklin wastewater treatment plant. The permit is effective July 1.

The city, among the nation's fastest growing for more than a decade, is building a $100 million treatment plant that will allow 16 million gallons of wastewater daily – up from the 12 million discharged at its current plant.

The new permit has been the source of controversy. A lawsuit by environmental group Harpeth River Watershed Association had contributed to delays in approval of the new permit.

Of particularly concern to the group and others is the amount of phosphorus that will be allowed into the river under a new permit.

But, City Administrator Eric Stuckey said, Franklin has continued to improve its phosphorous limits and that the permit reflects its ability to do that.

“That is more restrictive,” Stuckey said. “But that’s a level we’ve been able to permit and outperform over time. Some of the things in the lawsuit were things we were already working on in terms optimization of the operations of our plant. It’s difficult to credit one thing or another. It’s a really a focus on improvement and understanding our impact.”

In the announcement, TDEC Director Tisha Calabrese Benton explained the new permit will decrease the phosphorus levels allowed.

“The new permit holds the line on phosphorus levels as well as those of other pollutants,” Benton said.

The rate under the current permit is 5 milligrams per liter and is being reduced to an equivalent of 1.7 milligrams per liter. She explained that the system of measuring is changing, but TDEC did provide an equivalent level.

Benton added that the city of Franklin has proactively kept the phosphorus level well below the 5 milligrams allowed. She said while not addressing the city's efforts in the new permit, it does require Franklin to inform TDEC should there be any changes in the chemical discharges.

“It (the permit) also has an action level in it so that if they were to stray from what their action discharge had been the permit requires them to alert us even if it doesn’t raise to environmental permit limit,” she said.

The permit changes are "based on discussions that we’ve had with TDEC and other stakeholders,” City of Franklin Water Management Director Mark Hilty said. “The point of this is to be protective of the river. We are going to continue to exceed the expectations of the permit. I try not to look at the perspective of this permit is getting what we want. We want good stewardship of our resources and that’s getting what we want.”

The new permit comes after public hearings and a public comment period. Benton said additional meetings also were held with interested parties.

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Franklin had been operating under a permit that had not been updated since 2010. Benton said such permits are kept in effect even after expiration dates until new permits are approved.

The permit will expire on June 30, 2022, according to the NPSE permit document.

This is a developing story. Check back for updates.