Metrowest Daily News 6/5/09: Herbicide treatment begins at Lake Cochituate. Workers completed herbicide treatments of most of the areas of North Pond of Lake Cochituate affected by Eurasian milfoil, but a small portion inside and near the Natick border was left untreated. Last night, Department of Conservation and Recreation officials provided an update to the Natick Conservation Commission, and discussed possibilities of ridding the 2.7 acres of untreated area of the invasive weeds.