by Leslie Lytle, Messenger Staff Writer

At the May 20 meeting the Sewanee Utility District Board of Commissioners considered a request by the Wetlands Project coordinator Deb McGrath to extend the project a year or more. SUD manager Ben Beavers shared his concerns with the board.

The trial constructed wetlands, a research project undertaken jointly by the University of the South and the University of Georgia in 2015, studies wetlands’ effectiveness in cleaning wastewater. Elaborating on McGrath’s request to extend the project, Beavers said, “She wants to start sampling next summer, 2026, which would be 10 years [of operation], and get a year’s sampling to the summer of 2027. And she actually wants to go another year. I don’t know how I feel about that.”

“If they are going to continue using it, they need to take better care of it,” Beavers insisted. “They have to keep it mowed and weed-eated. There are enough mosquitoes there already.”

“The BOD [biological oxygen demand] in that lagoon has been affected almost out of range because of the duckweed and stuff that has crept in there,” said Board President Charlie Smith. [Note: BOD is a measure of the ability to support life based on the oxygen level of the water.]

“We’re going to explore ways to remediate that,” Beavers said. “If we use chemicals, I don’t know what the impact would be on their wetlands, but we have to be more concerned with the health of our lagoon than their project.”

Board member Clay Yeatman asked if there were biological controls for the mosquito problem, such as mosquito larvae eating gambusia fish.

“Before they started the project, there were millions of [gambusia]. Six months afterwards, we had duckweed and no gambusia.” The speculation is the aquatic environment would not support the fish due to the reduced BOD from the duckweed.

“Is the duckweed a problem in other lagoons?” Smith asked.

“Not yet,” Beavers said. “But there are geese and ducks and turtles that go back and forth [potentially spreading the duckweed].”

“I guess we can let it go through the summer and see what happens. It’s gotten to the point we need to shut it down unless there are good signs.”

Beavers will craft a response to McGrath stating the board would revisit keeping the project open if maintenance was kept up. Beavers will also request a legal agreement protecting SUD from liability.

The Messenger contacted McGrath inviting her to comment on the board’s decision.

“I agree with Ben. The duckweed has been a terrible problem. We certainly did not intend to bring duckweed in with the native plants that were installed. But aquatic invasives have a way of arriving on their own. Duckweed can be brought in by birds and other means. We tried seeding lagoon C with 100 grass carp [to control the duckweed]. We also installed an aerator to increase dissolved oxygen. A year later we couldn’t find any living fish. We would love to be rid of the duckweed.” McGrath is consulting with University Domain Manager Nate Wilson about the most effective chemical treatment. “It’s possible using chemicals to kill duckweed in lagoon C will kill wetland plants,” she conceded.

McGrath has hired a company to mow around the wetlands. She hopes to have an opportunity to talk with the SUD Board about her long-range plans. “The 2022-2024 monthly sampling demonstrated that the wetland is treating lagoon C water further, but two years isn’t really enough data to demonstrate anything more than a trend. I’d like to restart sampling the summer of 2026 through summer 2028 [to have ] a second consistent two-year monitoring record.”

In other business, the board discussed a complaint from a Jackson Point customer about dirt in his water. Beavers said SUD’s service line had been flushed, but pointed out, “hydrants are few and far between there.” SUD sampling at the customer’s meter and the nearest hydrant (one mile away) showed 0.23 turbidity, with 0.5 the allowed limit. Between 0.3 and 0.5 water begins to show signs of being cloudy, Beavers explained. SUD had received no complaints from other customers in the area. Beavers said there were many possible causes for sediment in the customer’s water. A leak on the customer side of the meter could be allowing dirt to enter the water line. Also, because the residence was a weekend home, the surge in pressure when the water was turned back on could cause sediment to break loose in the pipes. Beavers acknowledged the pressure was high in that area.

Pressure reduction was among the projects Beavers updated the board on. Failed pressure reduction valves were scheduled to be replaced at Jackson Point and Sewanee Summit. Pressure reduction valves in the Old Sewanee Road and Old Jumpoff Road areas were not functioning properly, according to Beavers, but the pressure demands were not as high there. SUD will replace the valves in the Old Sewanee Road and Old Jumpoff Road areas in conjunction with the Pressure Reduction and Leak Detection Project funded by SUD’s American Rescue Plan Act grant.

Other upcoming capital projects include the replacement of the membrane filters at the water plant, scheduled for Nov. 3-5; and painting the water tank, estimated cost, $400,000. Beavers is investigating grant opportunities.

Reporting on his research into firms to perform a rate study for SUD, Beavers said Raftelis, who initially quoted a $50,000 cost, would do a more limited analysis for $25,000-$30,000. Beavers also received a quote, substantially less than $25,000, from the firm who did Monteagle’s rate study. He will have a quote from the firm that did Big Creek’s rate study at the June meeting, giving the board three quotes to consider.