Lake Memphremagog is a fresh water glacial lake located between Newport, Vermont, United States and Magog, Quebec, Canada. The lake spans both Quebec and Vermont, but is mostly in Quebec. Most of the watershed that feeds the lake is located in Vermont, and is a source for accumulated phosphorus, sediments, and other pollutants. Cleanup efforts since the late 1980s have improved the water quality. The lake furnishes potable water for 200,000 people.