Minerva Lake may need ‘spot’ use of ProcellaCOR 

APA staff suggest taking over certain herbicide approvals, bringing fewer to the board

By Zachary Matson 

Minerva, the first Adirondack community to use a new chemical herbicide to kill invasive Eurasian watermilfoil in its namesake lake, plans to seek approval to use it again next year to “spot treat” returning milfoil beds. 

Minerva Supervisor Steve McNally addressed the Adirondack Park Agency board on Thursday and told board members the town would likely seek a permit next spring to use the herbicide ProcellaCOR to kill off beds of invasive milfoil that have started to rebound in recent years.

Minerva used the herbicide in 2020 — the first on a growing list of Adirondack lakes to do so — and found no milfoil plants for a couple of years following its use. At that time, the town treated about half of the 80-acre lake. McNally said it needs to use the herbicide now to treat small pockets of emerging beds, which he said is too costly to manage with contracted dive crews. 

“It’s been a very successful program,” McNally said. “I have not heard a negative thing about it and our fisheries are doing great.”

He said the spot treatment approach was expected as part of the initial strategy and would help prevent rapid expansion of milfoil beds and potentially a large treatment in the future. 

“With some spot treatment we may avoid a full treatment down the road,” McNally said. 

McNally said surveyors examining the lake this spring have found “a lot of immature plants.”

As more and more lake communities turn to the herbicide as a cost effective approach to killing back milfoil, the most pervasive aquatic invasive in the park, Minerva would mark the first to return to treat reemerging milfoil. Some lakes have proposed phased treatment approaches, using the herbicide in one area in one year and another area in a second year. 

During presentations about other proposed herbicide treatments later in the meeting, some board members asked about the idea of follow-up ProcellaCOR treatments. 

APA wetlands specialist Aaron Ziemann said the agency would review applications as they came but suggested the right circumstances could support additional treatments, as long as it was part of a broader multi-year lake management strategy. 

“It’s not out of the question that someone would be interested in another treatment, we need to see that the conditions are right and see that in the context of their overall efforts,” Ziemann said. 

Two more lakes given go ahead for ProcellaCOR, board mulls turning certain approvals over to staff

The APA board also approved two new lakes to use ProcellaCOR later during the meeting: Eagle Lake near Ticonderoga and Mountain View Lake in the northern Adirondacks. 

Both local lake associations are turning to the herbicide after years of managing milfoil by hand, a costly proposition for volunteer lake groups. The two lakes would bring to nearly a dozen the number of lakes across the park that have used the herbicide in the battle against invasive milfoil.

It’s possible the approval process for future ProcellaCOR applications could change, with fewer projects presented to the board. Instead, APA staff could approve the projects themselves if they meet certain criteria.

John Burth, who leads the agency’s regulatory program, asked for board member input into authorizing staff to approve new herbicide applications with some exceptions that would go before the board.

As the herbicide has grown more popular in recent years, presentations on similar applications projects have swallowed hours of meeting time, with the board ultimately approving all proposed projects. Outside of a rabid fight over using the herbicide in Lake George, most of the applications have faced little opposition. Though some residents throughout the park have questioned the long-term wisdom of using any herbicide in Adirondack lakes.

Burth suggested that projects that represented a lake’s first treatment, were backed up by a long-term management plan, included detailed plant surveys and aligned with the best timing to use the herbicide could get approved at the staff level. Staff could then keep board members updated on projects broadly, and board members could seek to bring any proposal up for board review. 

Proposed herbicide use that would impact protected species or was a re-application of a previously approved treatment area would still come before the board, Burth said. Board members also suggested maintaining review of projects on large lakes and those that drew significant public interest. All of the projects would still include notification to nearby landowners and opportunity for public comment.

Photo at top: Consultants survey Minerva Lake before applying herbicide to combat Eurasian watermilfoil in June 2020. Photo by Gwendolyn Craig