The Connecticut River after Tropical Storm Elsa looked like a chocolate milkshake. And the reason is pretty gross: rainwater runoff and raw sewage.
This dirty water makes its way into rivers because of century-old infrastructure called “combined sewer systems,” which merge stormwater and household water into one big pipe. And when it rains a lot, those pipes can get overloaded, forcing regional water officials to dump that dirty water directly into rivers and streams.
“Everything that gets flushed down a toilet or put down a storm drain is in that water,” said Andrew Fisk, executive director of the Connecticut River Conservancy. “It has significant public health impacts for people, and it also has impacts on the critters that live in the river.”
And in that raw sewage is a lot of bad stuff: bacteria, viruses and toxins.
“The Northeast, because we have some of the oldest wastewater infrastructure in the country, we tend to have more of these combined sewer overflows than other communities,” Fisk said.
Some of that infrastructure is more than a century old — engineered at a time when there was less focus on keeping rivers clean and more on getting poop away from people as quickly as possible.
“At that time, really, the most practical thing to do to get water — whether it was wastewater or rainwater — away from people and inhabited areas, was to … construct one pipe that caught it all,” said Nisha Patel, assistant director of the municipal wastewater program at the state’s Department of Energy and Environmental Protection.
Today, when the system works, the captured water gets treated before it's released. But when it rains a lot, the raw sewage can only go to one of two places. Into your basement or into rivers and streams. The latter was by design.
“You have these discharges that were sort of built into the system to prevent them from surcharging and ending up in people’s homes and businesses,” Patel said.
And recent heavy rainfall events like Tropical Storm Elsa meant lots of those discharges in Connecticut.
From late June through July 9, when Elsa hit the state, about 275 million gallons of storm runoff and raw sewage drained into state waterways.
“What we experienced in July was a significant portion of the total volume that we’ve seen in previous years,” Patel said. “How it compares over the course of the entire year will depend on how much more rain that we get, obviously, through August to December.”
A Giant Pipe
So what’s the solution? Well, one idea is to capture, treat, and release that dirty water.
To do that, you need a big pipe with a long name: the South Hartford Conveyance and Storage Tunnel, buried nearly 200 feet underground. It’s a project of the Metropolitan District Commission, the region’s water and sewer authority.
On a day in late July, we piled into a big cage hooked up to a giant crane. I asked Mike Surman, project manager for Kenny / Obayashi, the joint venture building the project, what this thing is called.
“This is a man cage,” Surman said, smiling.
“Person cage!” said Susan Negrelli, the MDC’s director of engineering.
The cage lifted us all off the ground, dangling for a few moments before we began our descent about 185 feet below the surface.
We hit the bottom and the cage door opened. As our eyes adjusted to the darkness, we looked down a tunnel that will run roughly 4 miles from Hartford to West Hartford.
Laid before us was a self-sustaining world for the work crews that are down here three shifts a day.
“The air, the piping, there’s a bathroom down here for them, you know what I mean?” Negrelli said.
Workers with headlamps stomped past us through red-tinted pools of muddy water. Conveyor belts and grout hoppers hung alongside walls of giant dark, dripping rock.
There was even a 20-ton locomotive down there, running deep into the tunnel.
“There’s segment cars that you can see down here. There’s a grout car that’s on the tracks back there,” Surman said.
This years-long project has faced delays. But when the whole system is operational in 2024, it’ll take in sewage and stormwater during heavy rain. That water will get pumped to a sewage plant, cleaned and released into the Connecticut River.
Fisk, with the Connecticut River Conservancy, said projects like this require big commitments.
“Time and money are significant aspects of this,” Fisk said. “We’re talking billions and decades.”
The tunnel project costs MDC customers and state taxpayers about half a billion dollars. It’s part of a larger $2 billion program, one the MDC is doing to comply with federal and state orders to clean up water.
Nick Salemi, a spokesperson for the MDC, said about 90,000 MDC member town customers, who are also state taxpayers, are paying for the majority of the project.
“The project has doubled MDC water bills … in the last decade and is currently the largest portion of MDC water bills for Member Town customers,” Salemi said in an email.
Fisk said tunnels have a place in reducing sewage overflows. But he said cutting back overall water use is also important.
“You can do that first by not having as much rainwater or stormwater directly channelized into gray infrastructure and pipes,” Fisk said. “The less water you have in that system, the less you have to deal with it.”
Since the federal and state orders went into effect, Negrelli said the MDC has cut sewage overflows by about half a billion gallons.
She said the tunnel is “the right thing to do for this area.” But she said she’s not sure if these massive underground projects will make sense in the future.
“We have water mains in Hartford that are from the 1800s. We have all of [these] aging brick sewers in Hartford that are crumbling,” Negrelli said. “Our position is, let us fix that infrastructure first and then maybe we won’t have to build as big of a tunnel the next time.”
Because at the end of the day, Negrelli said, clean water is important, but so is ratepayer money.
