Herbicide to Fight Milfoil in Beaver Lake Meadow

SOLitude Lake Management of Shrewsbury, Mass., has been contracted by the New Hampshire Department of Environmental Services (DES) to chemically treat portions of Beaver Lake to control non-native milfoil.

Beaver Lake Meadow will be treated with the herbicide Navigate (2,4-D BEE) on or about Thursday, June 2, in accordance with a permit issued by the New Hampshire Division of Pesticide Control.

Amy Smagula, Exotic Species Program coordinator for DES, has been checking the milfoil found in the area throughout the spring, and divers have manually pulled what they can, reducing the area to be treated with the herbicide considerably, she said.

Smagula said the milfoil found in the body of the lake has been eradicated.

Michael Lennon of SOLitude noted that a public hearing was held in April in Derry on the proposed herbicide use in the meadow area, and his company has sent out the necessary information on treatment plans to abutters. SOLitude will apply the herbicide and conduct checks following the treatment.

The meadow has been marked as to where SOLitude will distribute the herbicide using a spreader seed system. The dose is based on the surface of the area and the volume of water.

Abutters were notified about temporary limitations in the treated area, as follows: on the day of treatment, the shoreline will be posted with signs warning of the temporary water use restrictions that will be imposed immediately prior to treatment. They include: no swimming for 24 hours following treatment, within 200 feet of treated areas; and no use of the water for drinking, irrigation or for mixing sprays for agricultural or ornamental plants until further notice. The restrictions apply to all intakes within 1,200 feet of the treatment area, and to all wells within 50 feet of shoreline that is within 1,200 feet of a treatment area.

Smagula said the state tried diving several times this spring, “but the milfoil was denser than expected, and growing quickly. I saw expansion happen quickly over just a span of three weeks. I think the appropriate step here is to treat.”

She said she tightened the treatment footprint and reduced treatment from one long, 12.6-acre area to three small and discrete areas, for a maximum treatment total area of 7 acres, about half of what was originally proposed.

“All areas of active growth in the Meadows will be addressed,” she said.

According to a study referenced by Lennon, “Toxicology and Environmental Fate of 2,4-D” by Bob Reynolds, “2,4-D has been used on our crops and in our lakes and rivers for 50-plus years…For a pesticide, it is remarkably non-toxic or only slightly toxic to most non?target species, especially humans…At the carefully regulated concentrations used to treat variable milfoil, 2,4-D is essentially non-toxic to non-target species and disappears from the environment within days… The swim restriction in NH is 24 hours, primarily to keep swimmers away from 2,4-D pellets as they settle to the bottom, dissolve, and are absorbed by the milfoil plants… We have not documented any fish kills as a result of a 2,4-D treatment in New Hampshire.”

Derry Public Works Director Mike Fowler said the Town is not involved in the treatment program, but noted that information regarding the treatment plan has been posted on the Town’s Web site at www.derry.nh.us. He said DES and the company chosen have gone through the required permitting process and everything is in order.

The eradication of milfoil in Beaver Lake Meadow was determined necessary to keep milfoil from regenerating within Beaver Lake. Fishermen and boaters going between the meadow area and the lake pose a threat of reintroduction of milfoil to the lake, and the immediate addressing of the milfoil identified in the meadow is critical to overall control and eradication of the milfoil threat, Smagula said.

She will continue to check the entire lake and the meadow for milfoil but said it will take vigilance by lake users, led by the Beaver Lake Weed Watchers, to keep milfoil at bay.

Questions about the herbicide use can be directed to: Michael Lennon, SOLitude Lake Management, 590 Lake St., Shrewsbury, Mass. 01545, phone 508-885-0101 or email at  HYPERLINK “mailto:[email protected][email protected]