Phosphorous is a plant nutrient. High levels of phosphorous
can stimulate the growth of algae causing algal blooms. Algal blooms cause
the water to turn green, reduce water transparency, deplete the oxygen supply,
and create odor problems. Ultimately, these blooms alter fish and wildlife
habitat, impair scenic views, reduce recreational appeal, impair water supplies,
and lower property values. Algal blooms are a result of eutrophication. Phosphorous
contributors include farm and urban runoff, and municipal wastewater treatment
plants.
The 2000 Vermont Water
Quality Standards state: "In all waters, total phosphorus loadings shall
be limited so that they will not contribute to the acceleration of eutrophication
or the stimulation of the growth of aquatic biota in a manner that prevents
the full support of uses."
In addition, phosphorus criteria for Lake Champlain
have been established and range from 0.010 mg/l (as P) for the main lake
to 0.054 mg/l for the south lake B. The criterion for Burlington Bay is
0.014 mg/l or 14 ug/L (compare this number to the measurements in the table
above).
