2023 Aquastrike application DEP notice

Lettter from John McPhedran of the Maine DEP

July 17, 2023

Dear Lake Arrowhead shorefront owner:

A contractor for the Maine Department of Environmental Protection (DEP) will apply herbicide in
portions of Lake Arrowhead this Thursday, July 20, 2023 to control the invasive aquatic plant
brittle naiad (scientific name Najas minor). I am writing because your property is within or near the
treatment area. DEP will post notification at boat access sites and beaches near the treatment area.

The treatment objectives are 1) to reduce spread of brittle naiad within Arrowhead and to other
waters and 2) enable future control of this infestation with non-chemical means. The treatment is
timed to kill the brittle naiad before it forms seeds.

The herbicide Aquastrike will be applied because of its effectiveness on brittle naiad. The following
water use restrictions on the Aquastrike label apply to the treatment areas (product label found here
http://www.cdms.net/ldat/ldBRQ006.pdf):

  • Do not drink lake water for 3 days after treatment
  • Do not allow livestock to consume lake water for 1 day after treatment
  • Do not irrigate turf and landscape ornamentals for 3 days after treatment
  • Do not irrigate food crops for 5 days after treatment

There is no swimming restriction for Aquastrike but the DEP advises residents not to swim within
treated areas on the day of treatment as an added safety measure. The herbicide will be applied via
subsurface injection through perforated hoses from an airboat. The contractor will arrive early on
Thursday and the treatment will last most of the day.

A map showing the treatment area is attached to this letter and will be posted here:
https://www.maine.gov/dep/water/invasives/. 

A separate treatment targeting variable water-milfoil may occur later in 2023. If that occurs, landowners within the treatment area will be notified.

You may contact me at john.mcphedran@maine.gov or phone at 207-215-9863 if you have
questions about the project.

Sincerely,

John McPhedran

Biologist, Maine DEP