As part of the agreement, Canada and the United States are working, in cooperation and consultation with other levels of government, Aboriginal peoples, non-governmental institutions and the public to restore and protect water quality and ecosystem health. The Great Lakes Executive Committee (GLEC) serves as a forum for advising and assisting the parties in coordinating, implementing, reviewing and reporting on programs, practices and measures that support the implementation of the GLWQA. The GLEC, co-led by Environment and Climate Change Canada and the U.S. Environmental Protection Agency, includes high-level representatives from federal, provincial and regional governments, tribal, First Nations, Métis, local governments, water basin management agencies and other local public authorities. In addition, a formal committee structure has been established to involve GLEC member organizations in binational work to develop and implement measures to meet commitments in each of the ten areas identified by the GLWQA. From 1918 to the late 1960s, the IJC repeatedly reported pollution problems in the Great Lakes and their linkage channels as part of its border treaty jurisdiction. These reports included recommendations for action that formed the basis for the first Great Lakes Water Quality Agreement in 1972. Canada and the United States have agreed to reduce pollution in industries and communities and limit the amount of phosphorus that has entered lakes, resulting in excessive algae growth, particularly in the Erie Sea. New laws have reduced phosphorus levels in household detergents and municipal treatment plants have been upgraded or expanded. Eriesee has recovered rapidly thanks to these efforts, and the value of binational cooperation for environmental rehabilitation in all lakes has been touted internationally as an unprecedented success. Until 1978, the two countries expanded their approach to combating the many sources and types of pollution in lakes.

The 1978 Great Lakes Water Quality Agreement set itself the goal of ridding the Great Lakes of persistent toxic substances – pollutants that come from many sources and can harm the health of all species because they remain in the environment for a long time, with an approach that takes into account the entire ecosystem.