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. A 1987 protocol to the 1978 Great Lakes Water Quality Agreement added specific efforts to rehabilitate the most polluted areas of watersheds, known as “Areas of Concern,” and to develop management plans for the elimination of pollutants at sea level. The IJC was tasked with assessing progress in achieving the 1972 and 1978 objectives every two years and held meetings every two years before concluding each biannual report on the progress of the work. In 2012, the agreement underwent a substantial review, for example following previous reports and recommendations for evaluation by the IJC, and following a broad consultation and review process conducted by the IJC. The 2012 agreement contains nine objectives or objectives that both countries are committed to achieving, as well as ten annexes that set out commitments on specific issues that could affect the water quality of the Great Lakes. Environment and Climate Change Canada is leading the implementation of the agreement and working with a number of departments, agencies and agencies on both sides of the boarder representing governments, Aboriginal peoples, water basin management agencies and other local public bodies. Canada is cooperating with the Ontario government as part of the 2014 Great Lakes Water Quality and Health Agreement on Water Quality and Ecosystem Health and is working with Canada, which coordinates the activities of eight federal departments and three provincial departments to support the implementation of the GLWQA. In 2012, Canada and the United States, following extensive binational audits, consultations and negotiations conducted by the IJC and the two countries, amended the agreement again, expanding their commitment to address the problems facing lakes through nine specific objectives or objectives and ten annexes.

The 2012 Great Lakes Water Quality Agreement also took into account the commitments made to date to take the entire ecosystem into account in all binational work, as well as the overall goal of restoring and preserving the chemical, physical and biological integrity of the lakes. The Great Lakes Water Quality Agreement is an obligation between the United States and Canada to restore and protect the waters of the Great Lakes. The agreement provides a framework for identifying binational priorities and implementing measures to improve water quality. CEPOL coordinates U.S. activities under the agreement. As part of the agreement, Canada and the United States (the contracting parties) are committed to working towards a number of broad and specific objectives related to the quality of Great Lakes water quality.