$13M “Green” Sewer Project Unveiled

A mile of new stormwater drainage pipes. Thirty-seven manholes and 24 new catch basins. Three hundred feet of pervious concrete sidewalk, and seven “bioswales.”

The Greater New Haven Water Pollution Control Authority (GNHWPCA) plans to bring those public improvements to East Rock to capture roadway drainage north of Trumbull Street to about Humphrey and between Whitney Avenue and State Street.

Tuesday night two dozen East Rockers gathered at the monthly meeting of the SoHu Neighborhood Association on Pearl Street to hear a presentation about the plan by Giovanni Zinn, the project manager with the city’s engineering department, and Mario Ricozzi, the GNHWPCA’s manager of design.

The project is a continuation of an ongoing Yale Campus/Trumbull Street sewer separation project, and part of the city’s continuing program to separate storm draining from the sanitary sewer system. The overall goal of that effort is to prevent “combined sewer overflows” (CSOs) that periodically, during flooding storms, cause unseparated lines to mix the sludge water with the stormwater and send sewage into the rivers.

The new pipes—currently there are no separate storm drainage pipes, only sewer lines in the area—- will be installed on Whitney, Lincoln, Bradley, and Pearl. They will stormwater down to culverts at State Street that will send it into the Mill River.

On smaller smaller streets such as Clark and along Orange, instead of the “grey infrastructure” of new piping, the WPCA will install “green infrastructure,” namely the bioswales.

Area environmentalists have long called for more “green” as opposed to “grey” infrastructure in the GNHWPCA’s plans to reduce overflows and upgrade the East Shore sewage treatment facility.

New Haven’s bioswales will follow models (pictured at the top of the story) from New York City, which has installed about 200 of a planned 1,000, said Zinn.

The bioswales are planned to be low-fenced areas about five by 20 feet between curb and sidewalk. They will leave at least five feet of unimpeded sidewalk.

The design pitches the bioswales slightly below street level and with a curb cut to receive water flow from the gutter. They will contain trees and plantings, chosen for their ability to absorb, along with layers of dirt and gravel that will intercept the flow of water from the street gutter and infiltrate it down, mimicking nature, thereby reducing the amount of water that reaches the catch basin.

The plan calls for seven of these along Orange Street and a double-sized bioswales on Clark. The project’s managers will monitor the bioswales on Clark to see how much they reduce water reaching the catch basin.

That aspect of the plan drew the most interest from the audience on Tuesday night.

“You’re brilliant,” said Judy Nugent of Clark Street. She specifically complimented the placement of the bioswales in some of the no-parking areas along Clark Street.

In addition to pipes and bioswales, the third feature of the Phase 2A project will feature pervious concrete sidewalks on both sides of Clark Street beginning at State and moving west. Pervious sidewalks are concrete, but more porous than regular concrete and designed to send the water down into the ground below instead of letting it wash into the streets.

Zinn said that one small bioswale was installed on Trumbull Street, which had a specific drainage problem in connection with the previous phase of work, the years-long sewer separation project around the intersection of Trumbull and Prospect.

Similarly a small stretch of sidewalk on Court Street was redone three years ago in pervious concrete.

The East Rock project will be the first to employ green infrastructure of this kind on a larger scale. The bioswales will be monitored and function as pilots for other streets in the area and for other phases of sewer separation work in the future.

If the bioswales work, they may be installed on the narrower streets, avoiding the need to tear up the roadways for new piping, along particularly narrow streets such as Eld and Bradley.

Half the $13 million for the project will come half from a grant from the state, Department of Energy and Environmental Protection(DEEP) and the other half from borrowing, according to Ricozzi. The GNHWPCA will repay 60 percent of the debt, the city, 40 percent. That’s been the deal ever since the city arranged to fold its operations in with the new regional organization, said Ricozzi. The city did that to solve a one-time budget hole.

The GNHWPCA serves the New Haven, East Haven, Hamden, and Woodbridge.

The inconvenience is not expected to be grievous, said the officials.

As crews work on approximately 100-foot length pieces of the project at a time, portions of the smaller one-way streets like Clark and Pearl will need to be closed during the day, with some detouring; they will be opened at night. Work on Whitney will not impede two-way traffic on that avenue, officials said.

Green infrastructure is now required of new developments in the New Haven Combined Sewer area to reduce the impact of new developments on combined sewer overflows, according to the GNHWPCA.

“We’re one of the first” communities to deploy green infrastructure like bioswales, Zinn said.

He and Ricozzi both attributed that to greater comfort of the regulators such as U.S. Environmental Protection Agency with green infrastructure; the state’s Clean Water Fund‘s willingness to set aside a percentage of funding for green infrastructure for waste water management; and proven advances in the technology.

If the money comes through, work should commence this summer and finish by the fall of 2015, said Ricozzi.

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posted by: anonymous on January 29, 2014  3:14pm

Fantastic.  These should be standard practice all over the city.

They should be combined with “traffic calming” efforts, which narrow down streets and intersections in order to control the speeding that destroys the quality of life in most of our neighborhoods.

There’s no reason why every neighborhood street in New Haven needs to have a 20 foot wide pedestrian crosswalk at every single intersection.  It’s very dangerous to children, and encourages vehicle speeding.  Many cities are making 10 foot wide crosswalks the “design standard” at intersections along residential streets.  Vehicles have to slow down significantly before they can continue or make a turn. 

When Dan Burden was hired by residents and the city to come to New Haven, he recommended this change, as well as more bioswales, as the “low hanging fruit” for making our city a better place.

People wonder why the city often isn’t perceived as a livable place for families, and why crime is high because not enough people are out on the streets.  Poor design decisions is one of the big reasons why.

posted by: robn on January 29, 2014  3:15pm

This isn’t the first application of bioswales in New Haven, Chris Ozyck and URI helped a crew of volunteers install a bioswale in the Ronan Street Dog Park years ago. Its simple, handles a large volume of runoff and it works.

posted by: mstratton on January 29, 2014  3:25pm

A thought, can we do some burying of power lines and elimination of telephone poles as part of this effort. Sounds like we are digging anyway?

posted by: David Backeberg on January 29, 2014  3:33pm

I like the idea; don’t know if it will catch on with the amount of litter that people throw out of their car windows. Maybe we can occasionally toss some mulch on top to cover up the litter.

posted by: anonymous on January 29, 2014  3:35pm

MStratton is correct. Where is the big picture thinking?

“In Chicago, bioswales double as traffic calming curb extensions.”

posted by: Lisa on January 29, 2014  3:40pm

I am very excited about this project!  Hopefully it will have great success, and we can do this through out the city.  Thanks for covering, Allan.

posted by: webblog on January 29, 2014  4:43pm

@ mstratton on January 29, 2014 2:25pm
This new project has nothing what so ever to do with the Yale Campus/Trumbull Street sewer separation project which took place at the bottom of Prospect St Hill and Sachem St. Some 2&1/2miles away. 
This project is an installation of sewer line,  not a separation. The decision to begin here is purely a political decision wherein there are more deserving areas of the city still in need of sewer separation, which is the real goal of the state and federal clean water act.

Bury that thought Alderman Stratton, the routing and burying of power lines and the re-wiring into the houses would be cost prohibitive and you would be the first to decry the substantial increase to your UI bill.

posted by: Lisa on January 29, 2014  4:51pm

Webblog, you wrote “This new project has nothing what so ever to do with the Yale Campus/Trumbull Street sewer separation project which took place at the bottom of Prospect St Hill and Sachem St. Some 2&1/2miles away.”

That isn’t so.  Last night the GNHWPCA and City engineer told us that the sewer project was delayed because there was no sewer connection from Sachem and the canal area.  And so with the Trumbull St project, they installed the needed sewer line and continued on to Trumbull street.  Before that connection was made, the project couldn’t move forward.

posted by: webblog on January 29, 2014  5:46pm

@ Lisa

Sorry but I cannot discern what you are trying to convey.
According to the GNHWPCA here:


The first phase was complete in June 2013.

There is no reference to East Rock being a part of this project.

posted by: Kevin on January 29, 2014  6:02pm

Mike, there are fundamental differences between the excavation being done for the bioswales and that needed to bury utility lines, in terms of location and extent. Unless you want to get rid of the street trees (I know you do not), burying utility lines would require digging a trench in the middle of the street, not a good location for a a bioswale. A relatively small number of bioswales can help reduce run-off. It would not make a lot of sense a half dozen utility poles and the associated wires.

posted by: Jonathan Hopkins on January 29, 2014  6:34pm

This project’s farthest point from the corner of Sachem and Prospect is Clark and State Street, which is just over half a mile, not 2.5 miles. The project will install a new sewer line and stormwater retention/absorbsion infrastructure.

Do you know the condition of this area’s sewer pipes in relation to other areas of the city? I suspect that they are amongst the most in need of replacement since this area is one of the oldest and densley built-up parts of the city. Many of these streets and buildings were laid out and built during New Haven’s Canal Era between 1825 and 1835. Furthermore, this area has very narrow sidewalk planters, almost no vacant lots, and is densely populated and built-up. The only other places that have infrastructure this old are Downtown, Dwight, Trowbridge Square and Wooster Square. Most other neighborhoods in the city have infrastructure that was built 50-100+ years after the area where this project is being implemented.
The Hill, West River, Newhallville, Fair Haven and Dixwell have much wider sidewalk planters, lower densities, more vacant lots, larger lot sizes and more pervious surfaces to help with stormwater mitigation. So what do you mean by “more deserving areas”?

posted by: Lisa on January 29, 2014  8:01pm

We were told last night that these pipes are brick and from the civil war era..  We were also told that the pipes themselves are still in good shape, they just weren’t made for taking on this volume of sewage and storm runoff.  This the need for separation so that sewage isn’t dumped into the river when the pipes can’t handle the volume.