Nearly two weeks after the Burlington Department of Public Works discovered a broken pipe under the Winooski River, officials say they are on the verge of stopping the flow of sewage into Lake Champlain.
The pipe has been spewing more than 175,000 gallons of untreated wastewater into the river and Lake Champlain every day since at least July 12, according to the department.
By Tuesday, officials hope to begin operating a pump that would remove all of the contents of the broken pipe and send them to the Burlington North Wastewater Treatment Plant through an above-ground line, according to Rob Goulding, a spokesperson for the Department of Public Works.
So far, the price tag of the temporary rerouting project is about $700,000, Goulding said.
The pipe broke as a result of the torrential flooding earlier this month. A diving inspection conducted a few weeks before in June did not find any significant problems with the pipe.
“We could be looking at anything from a couple of small breaks to a whole section of pipe having been knocked away,” Goulding said. “Really, really hard to determine at this point.”
The water level has been too high and murky to safely deploy a diver to assess the damage.
In the meantime, Goulding said Burlington officials have created a three-part plan to address the break. First, they’ve tried to reduce the flow by asking some residents of Burlington’s New North End to limit what they send down their sinks and toilets.
It has been particularly important for residents to conserve wastewater during periods of high use, from 6 a.m. to 8 a.m. and from 6 p.m. to 8 p.m., which would “dramatically improve and enhance our ability to pump and haul wastewater until that bypass system gets set up,” he said. He encouraged residents to stay informed by signing up for alerts.
Recently, officials have been rerouting the sewage by pumping it from the broken pipe and hauling the waste to the Burlington North Wastewater Treatment Plant in tanker trucks. Officials are currently treating 75% of the flow through a new, temporary system. But between 175,000 and 200,000 gallons of sewage are still flowing into the river and the lake every day, Goulding said.
Before the department installed a pumping and hauling system, about 350,000 gallons of wastewater was flowing from the pipe into the river.
Finally, officials will work to permanently repair the pipe.In terms of a permanent repair, “all options are certainly on the table,” Goulding said.
“We are looking at long-term options, of course, to make sure we’re rebuilding a more climate-resilient pipe,” he said.
Asked whether a new pipe could be constructed above-ground to avoid becoming damaged in future floods — which are expected to become more common in Vermont due to climate change, Goulding said it’s possible, but would be complicated.
The pipe — the only one of which he’s aware whose route is underneath a river — was built in the 1950s.
“I’m not certain that modern construction practices would even bring a pipe under the river,” he said. “With that said, if we were to reroute it entirely right now, there would be private easements that would need to be worked through, there would be more pipe that would be necessary because it’s not as straight of a distance, there will be gravity challenges — all the kinds of different things that go into building a modern wastewater system that would need to be overcome.”
The flood has taken a significant toll on the effort to clean up Lake Champlain.
Oliver Pierson, lakes and ponds program manager for the Vermont Department of Environmental Conservation, said all of the pollution that has come from the storm marks a setback for Lake Champlain.
Sewer overflows occur on occasion across the state, usually during storms when combined wastewater treatment systems are overwhelmed with too much water. But a prolonged event such as the broken pipe under the Winooski River is unique, Pierson said.
The flooding more broadly, he said, has been an impediment to the phosphorus reduction efforts in Lake Champlain. Phosphorus, along with other nutrients found in sewage and other types of runoff, causes toxic cyanobacteria blooms that close beaches and threaten human and animal health.
State officials operate gauges at the mouth of each river that help them determine how much water and pollution are entering Lake Champlain at a given time. Preliminary calculations from the Lamoille and Missisquoi rivers show that each dumped into the lake extremely high levels of phosphorus, which is likely to have come from runoff in each associated watershed.
The data shows that “the storm brought, in seven days, 130% of the entire phosphorus load from 2022 for the Lamoille River,” Pierson said. In the Missisquoi River, the storm brought about half the phosphorus to Lake Champlain that it had brought in all of 2022.
“This is a terrible situation,” Goulding said, “an unforeseen situation, and one that is certainly the potential consequence of major, climactic, urgent situations like the torrential rains and flooding that we’ve encountered.”
Pierson said it’s important to rebuild infrastructure that’s resilient to increased flooding. And while Lake Champlain may be further from reaching its pollution reduction goals, he said the lake recovered from Tropical Storm Irene. With time and attention, it can recover again.
“We just need to keep implementing these projects to reduce stormwater runoff and erosion into our lakes, and then think about how to make them as resilient as possible to handle these major precipitation events,” he said.
