The Great Lakes cover nearly 95,000 square miles (250,000 square kilometers) and contain over 20% of the Earth’s surface freshwater. More than 30 million people in the US and Canada rely on them for drinking water. The lakes support a multibillion-dollar maritime economy, and the land around them provided many of the commodities — lumber, coal, iron — that fueled the Midwest’s rise into an industrial heartland.
Despite their enormous importance, the lakes were mined for well over a century as industry and development spread around them. In the 1960s, rivers like the Cuyahoga, Buffalo, and Chicago were so polluted that they were catch fire. In 1965, Maclean’s magazine named Lake Erie, the smallest and shallowest Great Lake, “a stinking, slime-covered graveyard” that “the point of no return may already have been passed”. Lake Ontario wasn’t far behind.
In 1972 the USA and Canada signed the Great Lakes Water Quality Agreement, a landmark pact to clean up the Great Lakes. Now, 50 years later, they have made progress, but there are new challenges and many unfinished business.
I study the environment and have written four books on US-Canadian administration of their shared boundary waters. In my view, the Great Lakes Water Quality Agreement was a game changer for environmental protection and an international model for regulating transboundary pollution. But I believe that the people of the US and Canada have abandoned the Great Lakes because they became complacent too soon after the pact’s early success.
Starting with phosphates
An important step in the joint administration of the Great Lakes between Canada and the United States came in 1909 when they signed the Boundary Waters Treaty. The Great Lakes Water Quality Agreement built on this foundation by creating a framework that allowed the two countries to work together to restore and protect these boundary waters.
However, as this is an agreement between governments and not a formal treaty between governments, the pact has no legal enforcement mechanisms. Instead, it relies on the US and Canada to honor their commitments. That International Joint Commissionan agency established under the Boundary Waters Treaty, implements the agreement and tracks progress toward its goals.
The agreement established common targets for control of a variety of pollutants in Lake Erie, Lake Ontario and the Upper St. Lawrence River, which represent the most polluted stretch of the Great Lakes system. An important goal was the reduction of nutrient pollution, especially phosphates from detergents and waste water. These chemicals fueled giant blooms of algae, which then died and decomposed, depleting the oxygen in the water.
Like the national water pollution laws enacted at the time, these efforts focused on point sources — pollutants released from discrete, easily identifiable points such as drains or wells.
Initial results were encouraging. Both governments invested in new sewage treatment plants and convinced manufacturers to do so Reducing the phosphate load in detergents and soaps. But as phosphorus levels in the lakes dropped, scientists soon discovered other problems.
Toxic Pollutants in the Great Lakes
In 1973 scientists reported a puzzling finding in fish from Lake Ontario: Mirex, a highly toxic organochloride pesticide primarily used to kill ants in the southeastern United States. An investigation revealed that the Hooker Chemical Company fired Mirex from its plant in Niagara Falls, New York. The contamination was so severe that New York State forbidden to eat popular species of fish such as coho salmon and lake trout from Lake Ontario from 1976 to 1978, which ended commercial and sport fishing in the lake.
In response to these and other findings, the US and Canada updated the Great Lakes Water Quality Agreement in 1978 to cover all five lakes and focus on chemicals and toxic substances. This version official took an ecosystem approach on environmental protection that takes into account the interactions between water, air and land – perhaps the first international agreement to do so.
In 1987, the two countries identified the the most toxic hotspots around the lakes and adopted action plans to clean them up. However there scholars of North American environmental regulations recognizeboth nations too often allowed industry to police itself.
Since the 1990s studies have identified toxic pollutants including circuit boards, DDT and chlordane in and around the Great Lakes, as well as lead, copper, arsenic, and others. some of these chemicals continued to appear because they were stubborn and took a long time to break down. Others have been banned but leached from contaminated sites and sediments. Still others came from a range of point and non-point sources, including Many industrial sites are concentrated along coastlines.
Many danger spots were slowly being rehabilitated. However, toxic pollution in the Great Lakes remains a huge problem this is largely neglected by the public as these substances do not always make the water look or smell foul. Numerous fish advice are still in force throughout the region due to chemical contamination. Industries are constantly bringing new chemicals to market, and Regulations lag far behind.
Nonpoint sources of Great Lakes pollution
Another big challenge is Pollution from non-point sources — Discharges originating from many diffuse sources, e.g. B. Runoff from agricultural fields.
nitrogen levels in the lakes have risen sharply due to agriculture. Nitrogen, like phosphorus, is a nutrient that causes large algal blooms in freshwater; It is one of the main components of fertilizers and is also found in human and animal waste. Sewage overflows from cities and waste and manure runoff from industrial agriculture carry large amounts of nitrogen into the lakes.
One way to address pollution from non-point sources is to set an overall limit for releases of the problem pollutant into local waters, and then work to reduce discharges to that level. These as Ttotal maximum daily loads, have been applied or are under development for parts of the Great Lakes Basin, including western Lake Erie.
But this strategy relies on states, along with voluntary steps by farmersto curb the release of pollutants. Some Midwesterners would prefer a regional approach, like the Chesapeake Bay strategy, where states asked the US government to write a comprehensive report federal TMDL for key pollutants for the entire Bay watershed.
In 2019, Toledo voters passed a Lake Erie Bill of Rights that would have allowed citizens to sue when Lake Erie was polluted. farmers challenged the measure in courtand it was declared unconstitutional.
global warming and floods
climate change now makes the cleanup of the Great Lakes more difficult. Warmer water can potentially affect oxygen concentrations, nutrient cycling, and food webs in lakes increasing problems and turn annoyances into big challenges.
Lake level at Presque Isle:high water mark
Floods driven by climate change threaten contaminate public water supplies around the lakes. Record high water levels are Eroding shorelines and destruction of infrastructure. And new problems are emerging, including Microplastic pollution and “forever chemicals” such as PFAS and PFOA
It will be a challenge for the US and Canada to make progress on this complex set of issues. Key steps include prioritizing and funding to clean up toxic zones, finding ways to stem agricultural runoff, and building new sewage and stormwater infrastructure. If the two countries can muster the will to aggressively address pollution problems, as they did with phosphates in the 1970s, the Great Lakes Water Quality Agreement gives them a framework for action.
Daniel Macfarlane is Associate Professor of Environment and Sustainability at Western Michigan University. This article is republished by The conversation under a Creative Commons license.