Impacted areas of Cobbosseecontee Lake will receive an herbicide treatment to combat Eurasian water milfoil Treatment is scheduled for Wednesday, July 13, 2022

July 11, 2022

The Maine Department of Environmental Protection's Invasive Aquatic Species Program (DEP) has contracted an herbicide applicator to control the Eurasian water-milfoil (EWM) in the north end of Cobbosseecontee Lake. SOLitude Lake Management will apply the herbicide on Wednesday, July 13, 2022.

The DEP previously treated portions of the north end of Cobbossee in 2019 and 2021. The 2022 treatment is warranted because of recent Eurasian water-milfoil plant finds by Friends of the Cobbossee Watershed (FOCW) survey crew. The DEP has determined that another herbicide application is needed to prevent this plant from spreading in Cobbosseecontee Lake and to other lakes.

Exact areas to be treated will be based on plant surveys leading up to the treatment date. A map showing areas to be treated will be posted on DEPs website by 5 pm on July 12, 2022. Residents abutting potential treatment areas received notification with the treatment date and information on the chemical to be applied: Procellacor EC (active ingredient florpyrauxifen-benzyl).

Treatment areas are subject to the following herbicide product advisories:

  • Do not use lake water for hydroponic, greenhouse or nursery irrigation before contacting the DEP to confirm the herbicide has dissipated

  • Do not use lake water for any residential or non-agricultural irrigation (such as shoreline property use for irrigation of residential landscape plants and homeowner gardens, golf course irrigation, and non-residential property irrigation around business or industrial properties) for 3 days following treatment.

  • There is no swimming restriction for florpyrauxifen-benzyl but the DEP advises residents not to swim within the treated area on the day of treatment as an added safety measure and in the event of a spill or other accidental release of the herbicide.

The treatment is part of a management plan that includes diver removal of remaining plants. The DEP, FOCW, Cobbosseecontee Lake Association and Cobbossee Watershed are working together to address this infestation.

Statewide, invasive aquatic plants are known to be present in 32 waterbodies, including associated river and stream segments. The DEP urges all boaters and lake users to clean, drain and dry boats, trailers, motors, and equipment between uses to prevent spread of aquatic invasive species in Maine.

Before moving boats, trailers, motors, and equipment between waterbodies:

  • CLEAN off any mud, plants, and animals from boat, trailer, motor, and other equipment. Discard removed material in a trash receptacle or on high, dry ground where there is no danger of them washing into any water body.

  • DRAIN all water from boat, boat engine, and other equipment away from the water.

  • DRY anything that comes into contact with the water. Drying boat, trailer, and equipment in the sun for at least five days is recommended if rinsing your boat, trailer parts and other equipment with hot, high pressure water is not an option.

For additional information, contact: David R. Madore, Deputy Commissioner