Iroquois homeowners return to non-chemical milfoil tactics

Observer courtesy photo by Pogo Senior
Lake Iroquois’ shoreline homeowners’ quest to control invasive Eurasian Milfoil continues with suction harvesting and lake-bottom mats this summer.

By Jason Starr

Observer staff

The Lake Iroquois Association has returned to suctioning up invasive Eurasian milfoil out of the lake this summer using a boat and divers after state regulators said they would deny its permit to apply a chemical herbicide.

During the last week of June, contractors from AB Aquatics of Henneker, N.H., performed what is known as “diver assisted suction harvesting” focusing on the lake’s beach and swimming area off Beebe Lane.

The divers plan to return in August to focus on an area around a rock island in the middle of the lake as well as the boat launch on the northwest shoreline.

The association last employed suction harvesting in 2016, a particularly bad year for the milfoil infestation, which, unabated, interferes with boating and swimming in the lake. Plans to apply herbicide were scuttled last summer and this summer when the association failed to receive approval from the Vermont Department of Environmental Conservation.

The association is made up of lakefront homeowners, who contribute to the association’s milfoil mitigation fund. The towns of Williston and Hinesburg — which comprise the majority of Lake Iroquois shoreline — have also budgeted annual sums to contribute to milfoil mitigation. Other funding has come from the Vermont Department of Environmental Conservation and the Lake Champlain Basin Program.

This month, the association plans to place mats known as benthic barriers at the bottom of the lake near the beach and fishing access. The mats kill milfoil as well as all other lake-bottom vegetation.

“It’s a bit of a controversial application because you’re covering the entire bottom,” said Lake Iroquois Association president Chris Conant. “It kills everything underneath the mat. Not everyone is psyched about it.”

On another front, a state-funded boat greeting and washing station will be staffed throughout the summer. Washing boats is a way to prevent the spread of milfoil from lake to lake.

“We are now washing all vessels that go in and out of the lake,” Conant said. “It’s really a great program.”

Meanwhile, the association is awaiting a formal denial of its application to the state’s aquatic nuisance control program to use the chemical herbicide Sonar. Having a written denial will help the association’s board members understand the reasons for the denial and determine whether a future application for Sonar, or a different herbicide, is warranted.

“We’re going to see what the denial concludes, see what the public comments were and reevaluate it in the fall,” said association board member Jaime Carroll.