Eversource tree-trimming woes continue

This week, a Connecticut nursery listed the price of a 10-foot hemlock tree at $250 — but Eversource ended up shelling out nearly 500 times that amount in a penalty for not trimming earlier the hemlock hedge that came within a circuit breaker of taking out the region’s electric grid three summers ago.

It represented a solitary instance of miscommunication rather than incompetence — but the episode showcases the challenges for Eversource in patrolling thousands of miles of lines with an arborist staff numbering less than 10 people, buttressed by a handful of outside contractors.

With Tropical Storm Isaias toppling nearly 9,000 trees onto Connecticut power lines, the vulnerability of the electric grid is under fresh review nine years after the 2011 storm Irene was followed by a Halloween nor’easter that year and then Superstorm Sandy in 2012.

With the disruptions of Isaias and the coronavirus pandemic, Eversource has

an $83 million budget to prune back or remove trees this year, part of a quadrennial cycle through the 149 municipalities it serves statewide.

Eversource counted more than 21,000 points of failure on its grid after Isaias, illustrating the magnitude of the problem four years after a Connecticut drought that weakened the root systems of many trees and exposed them to other perils like boring insects.

“We have about 17,000 miles of roadside distribution wires we trim back ... on a four-year cycle,” said Alan Carey, Eversource’s arborist manager focused on local lines in Connecticut. “When we find a tree that is severely compromised by any one ... defect, we make an evaluation as to whether we want to take it down.”

‘Many more ... than we can address’

That decision rests both on Eversource and its contractors determining the risk of a tree falling, and what piece of the grid it is threatening, with substations and primary trunks taking precedence over side streets that may have two dozen homes or less.

But in the instance of the $120,000 hemlock, a communication gap allowed the hedge line to grow unchecked until 2017, when it touched a highvoltage transmission line feeding electricity between Southington and its Frost Bridge substation just off Route 8 north of Waterbury.

Deemed important enough to be under the oversight of the Federal Energy Regulatory Commission rather than state regulators, transmission lines feed electricity from electric generation stations to the substations that in turn convert power for neighborhood distribution.

Eversource self-reported the June 2017 incident to the North America Electric Reliability Corp., which was created by FERC after the massive 2004 outage that blacked out large portions of the Northeast. NERC determined that a planned aerial inspection of the line did not occur due to what it termed “a transcription error on the arborist’s inspection schedule map.”

While an inspector spotted the problem on foot, the external contractor reported seeing a ribbon hanging on the hedge that led the individual to conclude that Eversource had “tagged” it and so was aware of the danger. Either way, the hedge continued to grow unchecked.

Eversource subsequently held an “all-hands” set of meetings with its contractors, with spokesperson Mitch Gross stating the company believes it now has procedures in place to eliminate any similar scenario going forward. The company uses a similar flagging technique to mark local trees for removal, which are then marked again with spray paint after the company obtains consent from property owners.

“There are many more hazard trees than we can address at any one time,” Carey said. “You get a good sense of what’s a threat to a large number of customers, what’s a threat to a smaller number of customers . ... Certainly somebody that has experience in this as an arborist is going to pick up defects and subtleties that the average homeowner is not.”

But it is an eyeball inspection that can miss candidates for removal, and Carey’s crew has no way of knowing whether any stand of trees will be hit with hurricane-force gusts as Isaias spawned.

In patrolling 60 miles of Danbury lines last year, Eversource listed trees in Danbury last year for removal, with none qualifying under the “hazardous” designation indicating higher risk to the local grid. The city was among the last statewide to see full restoration of power.

Hazardous tree count: 20K

In its 300-page maintenance plan and accompanying appendixes for its electric grid filed last January with the Connecticut Public Utilities Regulatory Authority, Eversource counted nearly 20,000 trees it deemed hazardous to lines and substations, coincidentally in rough alignment with the number of failures in the Eversource grid during Isaias.

Statewide, Waterbury got the most attention this year with scheduled maintenance along nearly 170 miles of lines, with Greenwich, New Milford, Woodbury and Westport eclipsing the 100-mile mark as well.

By comparison, Eversource worked on lines running 250 feet or less in multiple municipalities including Easton, Ridgefield and Berlin, where Eversource has its main Connecticut operations center.

Some property owners balk at trees being cut down — Eversource reported receiving more than 600 such refusals last year, with more than 15 percent of the total in Danbury and Ridgefield alone — but the utility says such rejections do not have a meaningful impact on the overall grid, with its crews moving to the next problem tree down the line.

Despite Isaias bringing down some trees that presumably would have been targeted for culling in future years, Eversource and United Illuminating cannot apply amounts budgeted for tree trimming in future years to tree crews it put to work after the storm, according to PURA spokesperson Taren O’Connor.

Carey anticipates any “Marshall plan” to speed up the removal of trees and branches would be met with similar resistance, while also noting any increased spending would be reflected in the bills of customers coming off a summer of high electric use.

PURA and the Connecticut General Assembly are now assessing the utilities’ vegetation management practices, with the possibility of new requirements. Carey said that some utilities trim more frequently than Eversource’s four-year cycle, with one benefit that communities see less change to the landscape due to trees not having as long a stretch to regrow branches.

“It is much less drastic a change for those trees, as well as customers viewing those trees,” Carey said.

Contributed photo Eversource will be trimming trees along more than 4,200 miles of roadside overhead distribution lines around the state. Here, a worker uses a chainsaw to cut a large branch from a tree.