NASHVILLE, Tenn. (WTVF) — Tennessee's population is booming.
Developers are building new neighborhoods in rural areas not connected to city sewer systems. In many cases, the developers build sewage treatment facilities for the new neighborhoods.
NewsChannel 5 Investigates first reported that half of the state's 360 rural sewage facilities failed to meet state standards and one-fourth have serious violations, including the ponding and runoff of sewage.
My previous reporting: 'Development is our main concern': Rural communities struggle with growth and lack of infrastructure
Now a NewsChannel 5 investigation reveals the state does not have basic design standards for covering how these systems are built.
In 2019, the Tennessee Department of Environment and Conservation attempted to pass "minimum design standards," but the proposal was met with a "hostile" bill backed by "developers," according to environmental groups that said new rules are desperately needed.
"It's a tremendously alarming time," said attorney George Nolan with Southern Environmental Law Center. "There's all this development pressure to put in more of these things and certain developers don't want to have standards."
Pictures from inside a gated Wilson County community show where sewage flowed into the yard of a luxury home and then into a storm drain that leads to Old Hickory Lake.
One family filed a complaint in 2022, stating "our two dogs have both had major issues that required ER treatment."
They said the wastewater killed their plants. The operators of the system said it was a mechanical failure that caused sewage to go off-site, and that it has been fixed.
The rural systems use something called Drip Dispersal technology, which serve residential subdivisions not connected to city sewer systems. Supporters said if they are well designed and maintained they can work safely.
Rutherford County's public water utility, the Consolidated Utility District, operates 80 Drip Dispersal systems across the county that serve nearly 9,000 residents.
They are built by developers then run by the public utility.
"This functions as the septic system for the entire neighborhood," said Brett McArdle with the Consolidated Utility District.
He was standing in a field surrounded by large houses in a 95-home neighborhood.
Drip Dispersal works like this — each home has a tank where sewage settles.
Wastewater is then pumped to a secondary area where it receives ultraviolet rays and is filtered through sand.
Lastly, the water is pumped into the large field and "dripped" out of underground pipes that have small holes back into the groundwater.
"This provides the entire subdivision with service without having to place septic tanks at each individual property," McArdle said.
But for it to work properly, the system needs a lot of land and soil that will absorb the water.
The Consolidated Utility District of Rutherford County adopted strict design standards that developers must follow.
"All counties don't have these standards many counties don't have any standards like this," Nolan said.
Back in 2021, the TDEC showed a senate committee video of failing Drip Dispersal systems across the state.
"This system is in Fayette County. Unfortunately we've got these systems all across the state," said Britton Dotson with TDEC.
"This is an indication to us it's not performing appropriately. It's ponded. It's flooding," Dotson said as video showed large puddles of wastewater in an open field near homes.
It came as TDEC wanted to adopt statewide design standards developers would have to follow.
But some lawmakers pushed back and proposed a bill that would have weakened TDEC's authority to regulate the systems.
"My impression is it came from certain developers," Nolan said.
It ended with TDEC being able to inspect the systems, but no statewide standards on how they're built, which would cover elements like the size of the drip field and the number of homes that can be attached.
"And when they're not designed well, and they are installed on the cheap, then you are going to have problems with ponding sewage in neighborhoods that smell bad," Nolan said.
Our investigation found a system in Fentress County that is a lagoon filled with sewage from a neighborhood.
TDEC inspectors found the "drip field was never installed" meaning it has no underground pipes or secondary treatment.
"Where is all that sewage going? Is it leaking from the bottom of the lagoon? Is that lagoon ever filling up? If it's never filling up, that's a problem," Nolan said.
A complaint from last year reported "raw sewage running down the shoulder of the road" in the neighborhood.
The lack of statewide design standards is one reason TDEC writes the following when it approves a new system: "issuance of a state operating permit in no way guarantees that this land application system will function properly."
"We shouldn't require any of our regulators to operate with one hand tied behind their back," Nolan said.
Rutherford County saw the need for strict standards and is forcing developers to follow them.
"We simply have very high standards that we don't wish to back off of," McArdle said.
Wilson County's utility district says it has also adopted strict standards, but many counties do not have any.
Environmental groups are going before the Tennessee Board of Water Quality Oil and Gas next week to push for strict statewide design standards for rural sewer systems.
