$1B city sewer project reaches halfway point

WHAT LIES BENEATH: Gov. Lincoln D. Chafee, center, surveys a tunnel that captures sewage overflow, with Narragansett Bay Commission Executive Director Ray Marshall, left, and Scott Early lead inspector at Gilbane-Jacobs. / COURTESY PETER GOLDBERG
WHAT LIES BENEATH: Gov. Lincoln D. Chafee, center, surveys a tunnel that captures sewage overflow, with Narragansett Bay Commission Executive Director Ray Marshall, left, and Scott Early lead inspector at Gilbane-Jacobs. / COURTESY PETER GOLDBERG

Deep under the streets of Providence, a three-phase, $1 billion tunnel has reached the halfway point in a massive construction project to capture sewage and stormwater runoff and move it along to wastewater-treatment facilities.
The federally mandated Combined Sewer Overflow Project is being done to meet the requirements of the Clean Water Act – that’s taking 20 years, with a project timeline from 2001 to 2021.
Old drainage systems in Providence, Central Falls and Pawtucket combined sewage and stormwater discharge, while newer communities have two separate systems, said Narragansett Bay Commission spokeswoman Jamie Samons.
Phase I of the sewer-overflow project was construction of a tunnel 26 feet in diameter that began in 2001. That first phase was completed in 2008 and began capturing overflow, said Samons. The project is now halfway into Phase II with a tunnel that’s 9 feet in diameter being connected to the first tunnel.
“This project is having, and will continue to have, a major positive impact on water quality in the upper bay,” said Save The Bay Director of Advocacy Topher Hamblett, who has been active in the organization for more than 20 years. Hamblett represented Save The Bay during the original stakeholder meetings, which began in 1996, to develop the Combined Sewer Overflow Project.
“Upwards of 5 billion gallons of sewage and polluted stormwater that would have otherwise been going into our local rivers was actually captured, stored and treated thoroughly at the Narragansett Bay Commission facility since this sewer overflow project went online in 2008,” said Hamblett.
“You can see the improvement in water quality. Every spring, summer and fall there are hundreds of boats on the Providence and Seekonk rivers fishing for striped bass and bluefish,” he said. “There’s been significant growth in community boating. You’ll see people in kayaks on these rivers. The public is using our waters much more than they were 10 and 20 years ago. “I think the project has a value that will go even beyond fishing and boating,” added Hamblett. “Rhode Island will be seen as a place that’s seriously addressing pollution problems and even in the urban areas, making its waters desirable and usable by the public.”
Gov. Lincoln D. Chafee took the halfway point as an opportune time to go underground in a small cage elevator on Dec. 3 to see the progress.
“By taking a proactive approach to the significant problem of sewage overflow, we are ensuring the health of our famous waterways and world-renowned coastline for generations to enjoy,” said Chafee. “What’s more, we’re putting Rhode Islanders to work in good-paying jobs that will provide lasting environmental benefits.”
Chafee came to see an earlier phase of the project when he was a senator, said Samons.
Twelve years into the 20-year project, one of the most important results is that with more runoff being captured and treated, the state has raised the rainfall levels that require closure of fishing areas. That’s because more rainfall means more runoff and that leads to more potentially harmful bacteria washing into fishing areas.
The net effect is less runoff and more areas open to fishermen, more often – and that equals more income.
“When productive areas of the bay are closed due to rainfall, we have less access,” said Mike McGiveney, president of the Rhode Island Shellfishermen’s Association. “Since the tunnel went online and captures more of the runoff, more of our productive areas are open, especially some in the upper bay around Rocky Point, Barrington and Conimicut,” said McGiveney. “We fish all those areas and they’re pretty productive, mostly for hard-shell clams and there’s been a very productive steamer bed up there.”
Tunneling equipment used in the project is similar to what was used to dig the “Chunnel” – the nickname for the Channel Tunnel under the English Channel connecting England and France, said Samons. The Rhode Island project stretches over 20 years because of the magnitude and the cost. Most of the project is an unfunded federal mandate.
Of the $350 million cost of Phase I, federal grants covered $9 million, said Samons. The remainder of the $1 billion project is being paid for by the ratepayers of the Narragansett Bay Commission.
“To get to affordability, we had to have it spread out to 20 years,” said Samons.
Phase I was a 3-mile-long tunnel 250-to-300 feet down in deep rock from the Field’s Point Wastewater Treatment Facility along the Providence River, taking a turn under the front lawn of the Statehouse and ending up west of the Foundry Complex, near Providence Place mall.
“We called that ‘the biggest project you’ll never see’ because it’s a huge infrastructure so far underground,” said Samons. “That tunnel in deep rock has a capacity of 65 million gallons of sewage.”
Overall water quality and the resulting impact on fisheries make the sewer project critical for the state.
“This project is primarily to prevent fecal coliform bacteria from getting into Narragansett Bay,” said Samons. “That’s not just from humans, but also from dogs, birds and all kind of animals.”
Phase II started in 2011 and has a tunnel about 30-feet deep for much of the way, which required more visible digging and street closures. A portion of the tunnel drops to a depth of about 280 feet to meet the other section. Phase II is on schedule for its targeted completion date of December 2014, Samons said.
Phase III is planned to be another tunnel in deep rock in Pawtucket and Central Falls, similar to the Phase I tunnel, with an estimated cost of $350 million to $450 million, said Samons.
Phase I cut down the sewage and stormwater runoff by 40 percent, said Samons. Phase II is expected to contain 60 percent of the runoff and Phase III is anticipated to capture 98 percent, she said.
Why only 98 percent?
“You can never capture 100 percent,” said Samons. “Water always wins.” •

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