Despite a snowstorm on Tuesday, March 3, about a dozen representatives from Eversource, the electric utility company that absorbed CL&P, visited Town Hall for a public information session on their proposed new substation and 2.3 mile transmission line from Cos Cob to 290 Railroad Ave.
Example of a new substation building. Eversource will present plans for the substation building at 290 Railroad Ave to the Architectural Review Commission on Wednesday, March 4, back at Town Hall at 7:00pm. Credit Leslie Yager
According to Eversource, the existing substation will reach its maximum capacity in 2017, and a new substation will address increasing demand.
The scene on Tuesday night was reminiscent of a science fair. The massive project was broken down into stations that formed a circle around the meeting room.
Eversource spokesman Frank Poirot, said that although the company announced the info session through utility bill inserts, local media and even handwritten letters to neighbors, they would take into consideration Tuesday night’s storm and possibly schedule another info session.
The 2.3 mile transmission line project involves trenching to a depth of about 6 ft. Poirot said that with older towns such as Greenwich, the utility company anticipates various contingencies for contaminated soil.
Contaminated Soil and Water
“We address it through our conditions imposed on the project by state environmental officials,” Poirot said. “Soil that is suspected, that we take out of a trench is put in lined dumpsters and taken to a licensed facility that will process it,” he continued, pointing out that dirt removed when trenches are dug does not go back into the trench anyway.
“The trench gets filled with a weak concrete mixture that doesn’t settle. You don’t get that cupping you used to get years ago,” he said.
“With water too,” Poirot said, with a nod to LI Sound, adding that although clean water can often go through the local sanitary system, well-water coming out of a trench goes into a frack tank, a water tank that separates out solids and makes it easier to process.
290 Railroad Ave., site of Eversource’s proposed new substation. Credit: Leslie Yager
290 Railroad Ave
“We have owned the lease since the 1970s,” Poirot said, of the property at 290 Railroad Ave, where Pet Pantry Warehouse is located. “We’ve subleased it to them,” he said of Pet Pantry Warehouse’s owners, who told Greenwich Free Press on Feb. 27 that they’d hired outside counsel on the issue of the property.
“We are the primary lease holder,” Poirot said of 290 Railroad Ave. ” The powers that be knew that we’d be doing expansion somewhere, some time, and purchased the long-term lease. Everyone who has been in there since then has been subletting from us.”
Workers laying transmission lines in trenches under a sidewalk. Workers are pouring a weak mixture of concrete into the trench in order to protect the lines. “If we had our druthers we’d go along the side of streets, but that’s not always possible. There’s about 100 ft open at any one time. About every 2,000 ft we put in a splicing vault,”said Frank Poirot an Eversource spokesman. A splicing vault is a concrete enclosure buried in the street and used to house the connections (splices) of an insulated under-street cable. Generally 8 ft high, 8 ft wide and 28 ft long. When the cables are spliced together during the installation phase, a controlled atmosphere is created by an enclosure or vehicle over the manhole. These vaults must be accessible at all times for maintenance purposes.
Underground trenching
The proposed routes for the new transmission line are all under ground and will connect the near maxed-out 1964 power station to the proposed sub station 290 Railroad Ave. Mr. Poirot said the location at 290 railroad Ave was selected many years ago for its location in the area with Greenwich’s highest demand for electricity and highest population density.
Eversource Spokesman Frank Poirot and Senior Engineer Peter Novak, show off a model of an underground splicing vault. Credit: Leslie Yager
HDD Horizontal Directional Drilling
Novak explained long distance horizontal drilling, HDD, in which drills are GPS guided. “I’ve seen a drill a mile under a lake come out the other side. They can go great distances under the ground. Part of this involves a HDD 1,400 ft long,” Novak said, adding that the downside is that the process is very expensive and therefore done in a situation that warrants it. For example, he explained the method would be used to run a line under water.
With the aid of GPS, drills correct themselves if they go off course. It starts with a pilot hole and then a drill cuts a bigger hole as it goes through. “Hopefully you do it just once and thread the line through,” he said, adding that all the lines are set up on platforms on saw horses. “Then you have 1,000 ft of line go down into the hole and hopefully come out the other side.”
The broken yellow line represents the proposed line where it would go under water, about 125 ft, according to Novak, in Bruce Park using HDD. The chain link line represents an alternate path. Novak said the alternate to HDD is an open cut, “We would damn it up on both sides. It’s a relatively shallow pond,” Novak said of the alternate route and open trench. Credit: Leslie Yaer
Mr. Novak explained the two yellow routes indicate the preferred HDD route (straight broken line) and chain alternate route, which would involve open cut through Bruce Park (chain link line). According to senior engineer, Novak, with HDD, people above ground are unaware of the drilling going on underneath. “These people could be playing a game and not even know we’re underneath them,” he said.
From the east of Bruce Park, and, in Cos Cob, Eversource we would do an HDD under the highway. Crossing I95, the line would then be placed in open cuts along Station Drive.
The approval process could take a full year, according to Helen Taylor of Eversource, who added that a link to entire Greenwich Substation and Line Project proposal can be found online.
See also:
CL&P, Now Eversource, Public Meeting on Proposed 2.3 Mile Line Project & Substation
Future of 290 Railroad Ave? Pet Pantry Owners Hire Outside Counsel