clean and clear

THE PROBLEM

Phosphorus promotes the growth of algae in lakes. In excessive amounts, algae can: Impair recreational uses Impair aesthetic enjoyment Impair water supplies Impair the biological community Produce toxins that harm animals and people

Phosphorus concentrations vary throughout Lake Champlain.
Where phosphorus levels are low, the water is relatively clear and blue.
Where phosphorus levels are high, the water is green and murky with algae.

Low phosphorus less than 0.014 mg/l	Moderate phosphorus between 0.014 - 0.025 mg/l	High phosphorus greater than 0.025 mg/l

Phosphorus concentrations in Lake Champlain are higher than the amounts allowed by Vermont’s Water Quality Standards, especially in Missisquoi Bay, St. Albans Bay, and parts of the South Lake.

For a map of phosphorus distribution in the lake, see the Lake Champlain Basin Program's Lake Champlain Atlas, "Phosphorus Concentrations " page showing phosphorus levels in Lake Champlain between 1990 and 2003.