The chemical and water quality characteristics of Lake Ontario reported prior to the International Field Year for the Great Lakes (IFTGL, 1972-1973) study have been reviewed and summarized. The low surface-to-volume ratio of this lake has allowed it to retain oligotrophic characteristics based upon biological parameters. However, some of the chemical paramerters, including the nutrient inputs and concentrations, suggest that eutrophication is imminent. In general, the water quality of Lake Ontario is good and projected increased in the loadings of major ions do not pose a threat to the use of this natural water resource during the rest of this century. The input of trace materials, such as the heavy metals and refractory organic compounds, is cause for concern since a significant contribution is made by an uncontrollable source, namely atmospheric precipitation. More stringent controls on the discharge of phosphorus, trace elements and synthetic organic compounds is recommended to preserve the integrity of Lake Ontario for the continued benefit of all users of its waters.
Allen, Eric R., "Lake Ontario Atlas: Chemistry" (1977). Government Documents. 90.