TRAVERSE CITY — Traverse City this week will begin construction of a temporary containment area around the low point of the city’s sewer system located behind the Record-Eagle building on West Front Street.
The containment area is like a bathtub and will hold up to 3,700 gallons of sewer overflow, said Art Krueger, municipal utilities director.
“It might boil over, but it won’t go into the river,” Krueger said.
It is just one component of work that needs to be done to the aging system, according to Krueger, who gave city commissioners an update on the sewer system at a special meeting held Monday.
The system has seen sanitary sewer overflows totaling 57,000 gallons in three rain events since late May. That compares to just one overflow in 2019.
A malfunctioning lift station in the May event on Front Street added to the significant rainfall, causing spillage to burst out of the sewer system through a manhole cover at the low point, flowing into the Boardman River and West Grand Traverse Bay, closing beaches for several days.
Krueger said long-term solutions are likely to take time and be costly.
“We’re going to be doing some capital improvement projects that are quite costly,” Krueger said.
Several commissioners want to see more specific information on what upgrades are needed now and over the next several years and what they will cost.
“I have to think the citizens of Traverse City prioritize fresh water ... and if it means extra dollars on their water bills, so be it,” said Commissioner Christie Minervini.
A bond that paid for capital improvements to the system several years ago will be paid off in 2022. That bond payment is $1.2 million per year, money that will be available to invest in sewer upgrades, said Marty Colburn, city manager.
Commissioner Ashlea Walter said she’d like to see costs for improvements to the more serious areas of the sewer system and see that work given priority.
Commissioner Tim Werner said the system is intended to be supported by sewer users and he supports raising rates.
“So that’s why we can still build sidewalks and have sewer rates that are intended to pay for the sewer,” Werner said.
Werner said he would support offsetting increases for some by lowering the base rate for those who use less water in their households, such as people who live alone.
Minervini also wondered how much of the sewer problems are caused by the increase in downtown development.
Werner said the problem is inflow and infiltration, which is defined as groundwater and stormwater that enter a sewer system and overwhelm it.
“It’s an old system,” Werner said.
Much of the needed upgrades include preventing that inflow, such as plugging up manhole covers and lining leaky sewer pipes.
Some work has been done, including televised inspections and cleaning of about half the lines in the system, with 1,166 feet lined.
The city is also looking at sump pumps that are illegally hooked up to the sewer system, though in inspections of more than 130 homes and businesses, just three have been found.
Pumps should be set to drain into the ground — not the sewer system, Krueger said.
Future projects include repairing a digester at the treatment plant at a cost of about $900,000 and rebuilding 470 feet of sewer lines below Randolph Street at a cost of about $200,000.
Needed upgrades also include installing a new pump near Sixth and Locust streets to divert significant flows directly to the wastewater treatment plant, as well as the installation of an underground equalization tank near Hall Street to provide storage during high flows.
It’s no secret that high water levels and climate change are wreaking havoc on sewer infrastructure around the state, with overflows occurring regularly in other communities, he said.
“It’s just alarming,” Krueger said.
Five years ago 10,080 feet of Traverse City’s sewer lines were submerged, affecting their ability to carry wastewater to the city’s treatment plant.
Since then Lake Michigan has risen 3.7 feet, with 18,374 feet of lines now under water.
“It’s about double what we saw just five years ago,” Krueger said.