CASCO — Maine environmental officials are declaring the once-infested Pleasant Lake in Casco is now free of variable-leaf milfoil.

Andrew Fisk of the Department of Environmental Protection said today that removing Pleasant Lake from the state’s list of infested water bodies shows how committed volunteers supported by a state-run effort can outgun one of the most persistent aquatic plants to infest Maine lakes.

Fisk said the Pleasant Lake-Parker Pond Association undertook a multiyear, methodical program of hand-pulling plants and laying barriers along the pond bottom to get rid of the milfoil, which had plagued the lake since 2001.

Thirty-three lakes in Maine remain on the list of water bodies infested with invasive plants.