Taking on ‘The Nine’ --- How Toxic Discharges to Lake Superior were Slashed and What it Might Mean for the Other Great Lakes

Louie Bruni
University of Windsor
Nicole Frantz
July 09, 2014
The Lake Superior shoreline

A novel pilot program has documented successful reductions to toxic chemical discharges and emissions– including huge cuts in mercury and dioxins – from sources surrounding Lake Superior. The results provide a template for similar toxic reduction programs in other Great Lakes.

The success was born out of a 1990 challenge from the IJC to the governments of the U.S. and Canada to virtually eliminate emissions and discharges of some persistent toxic substances into Lake Superior. The governments responded in 1991 by creating the Lake Superior Binational Program involving  federal, provincial, and state governments that surround the basin.

Within the program’s broad ecosystem approach is a more narrowly-focused initiative known as the Zero Discharge Demonstration Program. Its goal is the total elimination of nine pollutants from the Lake Superior basin.

Known as “The Nine,” these pollutants include four pesticides and commonly-known contaminants like mercury, DDT, and PCBs (polychlorinated biphenyls). A 20-year plan was mapped out with the goal of zero discharge of The Nine by 2020.  

Thus far, levels of all of The Nine have fallen since program launch. Basin-wide, mercury releases have dropped 80 percent and dioxins have dropped 85 percent. The amount of DDT and other banned pesticides around Lake Superior also has dropped significantly since 2001. As well, new regulations and policies are working to reduce the presence of the targeted pollutants.

But there is more to do.

One of the biggest future challenges for mercury reduction is taconite mining in Minnesota’s iron range, although the industry has committed to a 75 percent reduction by 2025. The Lake Superior Binational Forum held public meetings in 2013 which produced responsible mining recommendations, in line with Zero Discharge program goals. Another contributor to mercury contamination is coal-fired power plants, the largest of which are showing significant decreases in mercury emissions in the Great Lakes region. The province of Ontario has eliminated coal-fired power plants entirely

 The Lake Superior shoreline. Credit: Carri Lohse-Hanson.
The Lake Superior shoreline. Credit: Carri Lohse-Hanson.

“Like a manufacturer strives for zero defects or an employer has a goal of zero injuries, we have a goal of zero discharge,” says Carri Lohse-Hanson, Lake Superior Binational coordinator. “Defects, injuries and discharges inevitably happen, but what matters is how close can we get to the goal of zero.” Hanson, of the Minnesota Pollution Control Agency, has worked on the Zero Discharge program since 1992.

Meeting the 2020 targets does not come without challenges. After a 10- year decline, mercury concentrations appear to be on the rise in Lake Superior trout, and increased mining and other development are challenging future reductions. As well, new contaminants just now appearing on scientists’ radars are beginning to pose concerns about water quality. These include toxic substances in personal hygiene products, pharmaceuticals, and flame retardants.

Continuing reductions in mercury deposited in Lake Superior also will require action to control global sources, such as coal-fired power plants in Asia whose mercury emissions are transported long distances to the Great Lakes.

Initial successes of the Zero Discharge program came from plucking “low-hanging fruit,” such as cleaning up and containing concentrated areas of pollutants and engaging the public and policymakers in programs to reduce or eliminate the use of dangerous products.

An example is the reductions in PCBs – toxic compounds once widely used as coolants and insulating fluids in transformers and other applications. Banned in the U.S. since 1979, much of the equipment containing PCBs is naturally reaching end-of-life status and is being replaced with newer equipment that is PCB-free.

Given that these initial efforts have largely run their course, the road ahead will prove to be more challenging, and more creative thinking may be in order.

An example of legacy pollutants.  Credit: Gina Temple Rhodes, Western Lake Superior Sanitary District.The Zero Discharge program shows that stakeholders can work together to improve the health of the Lake Superior basin. Public efforts have gone a long way in aiding the government bodies involved in this initiative and are crucial to the success of the program. Individual efforts include practicing energy conservation and using efficient equipment, properly disposing of pesticides at household hazardous waste collections, and other actions which support the health of the basin.

The Lake Superior program intended for the efforts in Lake Superior to act as a model to be used to effect change in other Great Lakes, which have been more greatly impacted by human activity. Given the successes that have been encountered, initiatives in lakes such as Lake Erie - facing nutrient pollution concerns - can take inspiration from this amazing effort up North. Even if the zero percent contamination targets are not fully met, the Zero Discharge program can be considered a success and its lessons applied to other Great Lakes.


Louie Bruni
University of Windsor

Louie bruni University of Windsor - IJC Intern

Nicole Frantz

nicole frantz was a IJC Intern in the Windsor office from the University of Waterloo.