Centennial Study Expected to Provide New View of Great Lakes Contamination

The importance of clean Great Lakes water to human well-being has been a historic focus for the International Joint Commission.

More than 100 years ago, concerns about the connection between disease and sewage pollution triggered the IJC’s first-of-its-kind study of transboundary water contamination between 1912-14.

At that time, the IJC studied bacterial pollution in Canada and the United States boundary waters including four of the five Great Lakes to improve understanding of bacteriological water quality across the basins and examine how to address binational wastewater issues. The sampling area included three of the transboundary basins between Canada and the United States – the international Great Lakes, the Rainy-Lake of the Woods and the international portion of the St John River. Lake Michigan is a domestic waterway under the treaty and therefore was not included in the study. Today, Lakes Huron and Michigan are recognized as one hydrological unit, and since 1972 Lake Michigan has been included under the Great Lakes Water Quality Agreement.

Bacterial pollution of the Great Lakes continues to impact human health and economic aspects of citizens on all the lakes.

The lakes provide drinking water for an estimated 40 million in the two countries (and water for food and beverage products for millions more). Modern drinking water treatment greatly reduces health risks for the majority of residents and visitors, but the types and adequacy of protection may vary and an unknown number may drink untreated lake water.

Secondly, the Great Lakes nearshore, which includes beaches and shallow waters, is one of the most utilized areas in the region for recreation. Recreation, as an ecosystem service, hinges on clean water, and the full benefits of achieving a healthy nearshore zone is tied to improving many aspects of human well-being. The Great Lakes include some of the world’s greatest sandy beaches, but a growing trend of increasing beach closures has plagued many coastal communities.

Tourism has become a primary factor driving national economic activity, job creation, wealth and investment, and the economic value gained from Great Lakes beach tourism can be seen in the foregone benefits of beach closures.

One study of economic loss from beach closings in the state of Michigan found closing all Lake Michigan beaches would result in an economic loss of $2.7 billion. A literature review prepared for the Ontario Ministry of Natural Resources estimated the value of Great Lakes beaches between $210 to $262 million per year. Additional analysis in the United States suggests that a 20 percent reduction in Great Lakes beach closures and advisories would result in an economic benefit of $130 to $190 million per year. Therefore, Great Lakes beaches and nearshore areas serve not only as a treasured natural resource, but are a vital economic driver for surrounding communities that require protection against further degradation.

The Great Lakes basin today faces numerous water quality challenges impacting drinking water sources and recreation, as well as public recognition that the lakes should be protected. A variety of identified problems include nonpoint sources such as stormwater and agricultural runoff, as well as sewage blending facilities and combined sewer overflows (CSOs). These sources contribute E.coli bacteria and pathogens, nutrients, as well as pharmaceuticals and other contaminants of emerging concern, resulting in issues surrounding the safety of recreational and drinking waters.

These ongoing water quality challenges have led to the public questioning how all of this affects their health. Many sites along the shoreline also require restoration and protection (including Areas of Concern) and major investments in restoration have been made by federal, state and local governments, with the Great Lakes Water Quality Agreement continuing to lead the binational approach.

Key questions have emerged as these restoration projects moved forward, including:

• Is nearshore water quality getting better or worse?
• What is the source of changing nearshore water quality?
• What are the public health risks associated with changing nearshore water quality?

To answer these questions, the IJC’s Health Professionals Advisory Board (HPAB) will undertake a comparison project incorporating data and locations in the Great Lakes and connecting waterways from IJC’s 1913 study, and include Lake Michigan in the analysis.

Existing modern data from similar locations will be used to compare with bacterial trends identified by the 1913 study, and analyze water quality changes between the original study and today. The project also will identify science and management gaps that are impacting water quality restoration of coastal ecosystems.

Improved DNA-based methods, which allow researchers to track the sources of fecal bacteria and microbes, provide an advantage for today’s study. Increased use of these microbial source tracking methods in the Great Lakes has led to sizeable data sets at the state and provincial level in both countries. The HPAB will review the data sets from provincial and state partners to examine how bacterial contamination has changed in the last 100 years in all five Great Lakes, and what new technologies would support detection and source tracking to protect public health.

As part of this project, an upcoming workshop led by HPAB will assess the current state of transboundary biological water quality data and monitoring in the Great Lakes, and discuss the need for binational investment in a basinwide fecal bacterial/microbial water quality reassessment. Following some of the strategies of the 1913 study could provide a framework for future binational action to examine fecal bacteria based on modern bacterial source tracking methods, aimed at maintaining nearshore water quality. The workshop is planned for 2019.

Ideally, the proposed framework will help improve restoration efforts associated with bacterially contaminated waters, increasing TMDLs (total maximum daily loads) of contaminants and algal blooms. Improved information on bacterial sources also would inform binational investment in storm and wastewater treatment, and serve as a step toward achieving the IJC’s recommendation in its 2017 Triennial Assessment of Progress Report for zero discharge of inadequately treated or untreated sewage into the Great Lakes.