New technology coming to Wastewater Treatment Plant will kill stench at landfill

CLARKSVILLE, TN (CLARKSVILLE NOW) – The city’s Wastewater Treatment Plant is one step closer to a $40 million upgrade, one that should bring to an end the seasonal stench coming from the landfill in Woodlawn.

The project will get $15 million in funding from the American Rescue Plan Act.

“This grant funding will allow for important infrastructure upgrades that will benefit residents and businesses throughout the community,” states Sen. Bill Powers said in announcing the grant.

The big project: Thermal dryers

The grant will help pay for a new six-story building containing thermal dryers that will be constructed on the current wastewater plant site, according to Mark Riggins, general manager for Clarksville Gas & Water.

Thermal dryers dry out the leftover sludge – a byproduct of the water treatment plant’s purification process – making it easier to properly dispose of in ways besides just dumping it in the landfill, Riggins said.

Rhonda Fulton, marketing coordinator for Gas & Water, described the thermal dryer process.

“Dewatered wastewater sludge is tumbled in a rotary drum with an added heat source to dry the sludge even further to create a Class A biosolid. It will then get pelletized to create a product that is easier to handle,” she said.

After the sludge is removed for processing, the purified liquid is emptied into the Cumberland River, and that has been the practice from the beginning. For those concerned about the health of the river, Riggins said the purified wastewater is cleaner than drinking water.

The leftover sludge has been sent to the Bi-County Landfill. “The solids themselves, they are treated, and there (are) different ways that you can treat those and then dispose of those,” Riggins said.

Damage from the flood

Before the 2010 flood, crews at the Wastewater Treatment Plant processed the sludge to a class that they could be applied to land. “And people use that as fertilizer,” Riggins said. “We hauled it out there to a farm, or something like that, that they wanted, and then we had a … manure spreader that people could load into that and then spread onto their farms.”

According to epa.govthe end product of wastewater treatment plants is often a Class A humus-like material without a detectable levels of pathogens that can be applied as a soil conditioner and fertilizer to gardens, food and feed crops.

But Riggins said the flood caused major damage to the wastewater plant, and going back to the process of creating fertilizer was going to be expensive. “That sludge … it’s (called) biosolids, right now it is taken to landfill and disposed of.

“Now, back then when that decision was made, the landfill was willing and happy to take that,” he said.

But over the last several years, the smell has become a problem. “There (are) a lot of complaints (from nearby neighbors) about the smell at the landfill,” Riggins said.

Mark Neblett, executive director for the Bi-County Solid Waste Management System, said they get about five loads of sludge a day, and it smells pretty bad.

“The 0ther problem is, it’s hard to blend with the other waste to get compaction,” Neblett said, noting that if there is too much sludge mixed in with the regular refuse, it creates a kind of quicksand, causing heavy equipment to get stuck .

Long-term solution

When looking for a solution, Riggins said a consultant suggested Gas & Water haul the sludge to a different landfill, at a cost of $15 million.

“I just felt like that was a waste of ratepayers’ money,” he said. “If I am going to spend $15 million, I want this to be something that is going to work for this plant for eternity.”

Riggins said that with the new thermal dryers, the output will be reduced by up to 70%, and the process will allow the sludge to be once again be classed to use as fertilizer for farmers.

“We are grateful to the State of Tennessee Department of Environment and Conservation for their approval of our grant application,” Clarksville Major Joe Pitts said. “The funding will help solve a long-standing issue at our wastewater treatment plant. Credit to Mark Riggins and our employee family at CGW for their work in securing these funds.”

The next step is for the project to go out to bid, and the project should be complete in about two years, Riggins said.