November 22, 2013
BOURNE — With motors from herbicide applicators revving in the background, NStar senior arborist William Hayes pulled a pitch pine's needle-covered branch through his bare hand.
"You can feel a little tackiness, but it's not sprayed to drip off or to run off," Hayes said about the chemical mix applied to the 5-foot-tall tree about three minutes earlier.
After four years of debate and controversy, NStar resumed using herbicides this week on its rights of way on Cape Cod.
On Thursday, company officials demonstrated how they apply herbicides beneath a 25,000-volt distribution line on Joint Base Cape Cod that serves large parts of Sandwich. The company has adhered to a voluntary moratorium on herbicide use on the Cape since 2009 when activists raised concerns about the possible effects of the practice on public health and the environment.
NStar officials say their vegetation management program accounts for less than 1 percent of the total herbicide use on the Cape, that it's safe and that, combined with other measures, it's the most effective way to ensure trees don't threaten power lines.
A week ago the state approved a plan to allow NStar to use herbicides for the remainder of the year.
"This is one of the tools to do the job," Hayes said during the bumpy drive to a work site where NStar's vendor, Vegetation Control Service Inc., of Athol, was applying the herbicides.
Before entering the work site, VCS right of way supervisor John Chicoine offered a permethrin spray to help deter ticks and warned about unexploded ordnance and other potential hazards.
A crew of six hauled 40-pound mist blowers along the right of way as another crew member kept up on an all-terrain vehicle, carrying 18 2½ gallon jugs of the herbicide mix for refills.
The mix used this fall includes 10 percent Krenite and 3 ounces of Escort per 100 gallons of water, as well as about 1 percent of Cleancut, a penetrant that helps the herbicides get into the leaves. In addition, an agent in the mix called Point Blank makes the droplets stick together and prevents the drifting of the herbicides beyond the intended target, Hayes said.
Krenite and Escort have far lower toxicity levels than nicotine or caffeine and are considered almost nontoxic, according to a scale of the amount of a toxicant needed to kill 50 percent of test animals cited by the Penn State College of Agricultural Sciences and the LSU Ag Center.
The ideal spacing is about 10 feet on either side of each crew member, Chicoine said. The crews use hand signals and voice signals to stay together as a unit, he said.
Because many of the leaves on deciduous trees have already fallen off or browned, the application and herbicide mix used this fall is focused on conifers, the most prevalent of which is pitch pine, Hayes said.
The solution is purposefully viscous to prevent drift. Its application looks like a leaf blower shooting silly string.
The crew members aim primarily for the top of the plant, Hayes said.
It can take six to eight months for a coniferous tree to succumb to the herbicides, Hayes said. Only those plants that pose a danger to the power lines are treated, he said.
Scrub oak, for example, is OK to leave in many locations because it grows only 12 to 15 feet tall, while red oak is bad because it can grow 60 to 80 feet tall, Hayes said.
As targets are eliminated from the right of way, and beneficial low-growing plants prosper, fewer crew members and less herbicide are needed, Hayes and NStar spokesman Michael Durand said.
For many on Cape Cod, however, nothing but a complete halt to the use of herbicides is acceptable.
"I still have concerns about what they're doing, and it's clear that a lot of Cape Codders do," said Sue Phelan, director of GreenCAPE, a nonprofit organization opposed to the use of herbicides.
Phelan said she believes the state should have required that NStar renotify residents if herbicides will be used near their homes and questioned whether enough is known about the chemicals and their possible chronic detrimental effects.
"People are completely stressed not knowing if they are going to be here yesterday, today or tomorrow," she said. "The long-term consequences are even more troubling."
NStar notifies towns directly of the planned work, Durand said.
"We follow all regulations regarding notification and work very closely with the state and the local towns to answer any questions they may have," he said.
