Great Lakes Water Quality - ACS Publications - American Chemical

Chapter 10

Great Lakes Water Quality A Case Study D. J . Williams

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Inland Waters Directorate-Ontario Region, Canada Center for Inland Waters, 867 Lakeshore Road, Burlington, Ontario, Canada L7R 4A6

Pollution of the Laurentian Great Lakes exemplifies the serious problems associated with the impact of human activities on a major aquatic ecosystem. Problems have included serious bacteriological contamination, cultural eutrophication and contamination by hundreds of anthropogenic, potentially toxic substances. Management of the Great Lakes is divided between Canada and the United States and involves eleven governments at federal, state and provincial levels. Despite this environmental and institutional complexity, the Great Lakes have responded dramatically to remediation initiatives. Human impacts on the lakes associated with development of the Great Lakes Basin are discussed in the context of the unique binational arrangements agreed to by the two countries to restore and protect this shared, unique global ecosystem. The Laurentian Great Lakes of North America are unique. Formed in basins left by the receding glaciers some 12,000 years ago, they are the largest body of freshwater in the world containing nearly 20% of the total standing freshwater on the earth's surface. Lake Superior is the world's largest freshwater lake in surface area and third largest in volume (i). The Great Lakes are composed of five interconnected lakes in a single watershed comparable in size to the area of Central Europe (Table I; Figure 1). The international boundary between Canada and the United States passes through the lakes with the result that each lake is shared by both countries with the exception of Lake Michigan which is entirely within the United States. In Canada, the watershed lies almost completely within the Province of Ontario, but in the USA, it is divided among eight states. Thus, not only are the Great Lakes a unique global feature but their management which is the responsibility of eleven governments at federal, state and provincial levels has also presented some unique challenges.

0097-6156/92/0483-0207$06.00/0 © 1992 American Chemical Society Dunnette and O'Brien; The Science of Global Change ACS Symposium Series; American Chemical Society: Washington, DC, 1992.

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THE SCIENCE OF GLOBAL CHANGE


Table I. The Great Lakes Basin ~ Physical Features and Population Superior

Michigan

Huron

Erie

Ontario

Totals

Elevation (m) Length (km) Max Width (km) Ave Depth (m) Max Depth (m) Volume (km3)

183 563 257 147 405 12,100

176 494 190 85 281 4,920

176 332 245 59 229 3,540

173 388 92 19 64 484

74 311 85 86 244 1,640

22,684

Area (km2) Drainage Basin Area (km2) Total Area (km2)

82,100

57,800

59,600

25,700

18,960

244,160

127,700 209,800

118,000 175,800

134,100 193,700

78,000 103,700

64,030 82,990

521,830 765,990

4,385

2,633

6,157

1,402

1,146

10,210

191

99

22

3

6

558,100 180,440 738,540

13,970,000

1,321,000 1,051,119 2,372,119

11,347,500 1,621,106 12,968,606

2,090,300 4,551,875 6,642,175

Shoreline Length (km) Retention Time (years) Population U.S.(1980) Canada (1981) Totals

13,970,900

Source: Adapted from ref (2)

Figure 1. The Great Lakes Basin.

Dunnette and O'Brien; The Science of Global Change ACS Symposium Series; American Chemical Society: Washington, DC, 1992.

29,287,800 7,404,540 36,692,340

10. WILLIAMS

Great Lakes Water Quality

209

The quality and abundance of Great Lakes basin resources have been the foundation of the region's development since earliest European settlement. Indeed, in a little over a century, the Great Lakes Basin has evolved from a backwoods subsistence economy to a highly geared industrialized society. By way of current example: • •


• • • •

30% (7.5 million people) of Canada's population and 20% (30 million people) of the United State's population live in the Great Lakes drainage basin; Twenty-four million people rely on the Great Lakes for drinking water supply; Almost one half and one fifth of Canadian and U.S. manufacturing, respectively, are located in the Great Lakes Basin; One half of the $150 billion-a-year Canada/U.S. trade starts and ends in Great Lakes states and province (Ontario); Commercial and recreational fisheries total over $160 million and $1 billion per year, respectively, with about 2 million people participating; Great Lakes shipping is an important means of transporting bulk goods cheaply (e.g., in 1980, Great Lakes shipping transported 225 million tons of cargo).

The exponential growth in population and technology that has occurred in the Great Lakes Basin has resulted in human activities degrading even these large bodies of water. It is not surprising that the Great Lakes have been subjected to such degradation. Exploitation of resources for economic gain at the expense of valuable ecosystems is a pattern that has been repeated all too often in every country in the world. Since early settlement, the vastness of the Great Lakes has generated an attitude, which in part remains today, that the lakes have an infinite capacity to absorb human abuse and waste. The chronology of human mismanagement of the lakes and the effects on water quality and use have clearly demonstrated the fragility of this ecosystem. Seen in this light, the uniqueness of the Great Lakes fades. They become simply a microcosm of events as we see them on a global scale. This paper discusses some of the impacts of development on the Great Lakes. Efforts that have been made to resolve individual problems are also discussed including the unique Canada/U.S. institutional framework for addressing these issues. Emphasis is placed on eutrophication and toxic substances, issues which have been the major focus of concern over the last three decades. Chronology of Human Impacts on the Great Lakes The nature of human impacts on the Great Lakes relates closely to historical development and land use in the basin which, in turn, relate closely to the geology and physiography of the watershed. The southern part of the basin consists largely of Palaeozoic sedimentary rocks. Land use consists primarily of intense



210


urban/industrial development and agriculture. The northern part of the basin lies largely within the Precambrian Shield where settlement is more sparse. Impacts are due primarily to forestry and mining with only localized effects related to industrial and urban land use. As a result, both the nature and severity of the resultant human impacts are quite different when comparisons are made between the northern lakes (Superior and Huron) and the southern lakes (Erie and Ontario). The former remain close to pristine conditions, while the latter manifest the signs of degradation related to a variety of human activities. Early explorers of the Great Lakes Basin found a system in harmony with indigenous native cultures. Major signs of change started coincident with European settlement of the Basin around the 1800s (5-5). Deforestation of the Lake Ontario drainage basin for agricultural purposes caused reduced flows at critical times for fish and made large stretches of streams uninhabitable by reason of increased temperatures and heavy siltation. Moreover, the construction of dams blocked spawning migrations. As a result, Lake Ontario Atlantic salmon were in serious difficulty before 1850 and extinct by 1900 (4). Hartman (6) recorded comparable physical changes for the Lake Erie basin and in addition drew attention to extensive marsh drainage in the early years of settlement. As settlements grew and prospered along the shorelines, human waste discharged into the streams and lakes resulted in contaminated drinking water supplies and serious epidemics of typhoid fever and cholera through the 1930s. Continued industrial growth was accompanied by oil pollution in the 1940s and accelerated eutrophication in the 1960s. By the late 1960s degradation had become so extreme, particularly in the west and central basins of Lake Erie, that headlines such as "Lake Erie is Dead" were appearing in the news (7). In the interim, fisheries of the Great Lakes continued to be impacted by other factors including overfishing and the introduction of exotic species such as the smelt, alewife and sea lamprey. The sea lamprey drastically reduced lake trout stocks, particularly in Lakes Huron and Superior (4). Today, contamination by hundreds of potentially toxic substances via municipal and industrial discharges, land runoff and atmospheric deposition is the major environmental problem in the Great Lakes and will continue to be so for some time into the future (8). The Institutional Framework The involvement of eleven governments has presented both unique difficulties and opportunities in managing the Great Lakes. In an effort to cooperatively resolve problems along their common border, Canada (actually the UK) and the United States signed the Boundary Waters Treaty in 1909. This document has as its major premise that neither Party may use the water on its side of the border to the detriment of water, health or property of the other side. The Treaty also established the International Joint Commission (UC), a unique binational organization, as principal overseer and arbitrator of any disputes that should arise including those related to water and air pollution, lake levels, hydroelectric power generation and other issues of mutual concern. With the passage of time, a wide array of environmental problems became evident, particularly cultural eutrophication due to excess phosphorus inputs. In



10. WILLIAMS

Great Lakes Water Quality

211

1972, the first Great Lakes Water Quality Agreement (GLWQA) was signed by Canada and the United States to restore and maintain the water quality of the Great Lakes. The 1972 Agreement provided the focus for a co-ordinated effort to control cultural eutrophication by reducing phosphorus inputs. The UC was also empowered to review and assess progress under the Agreement. In 1978, the Agreement was revised and expanded to recognize the need to effectively manage toxic substance loadings into the Great Lakes. An "ecosystem approach" was also embodied in the 1978 Agreement. This approach recognized the need for a more integrated and holistic perspective to protect water quality and the health of the entire Great Lakes ecosystem (9). The 1978 Agreement, with minor modifications incorporated in 1987, is the current cornerstone in the bilateral framework for joint management of the Great Lakes. Commitment to the Agreement is largely political and fluctuates depending on political attitudes. Given this, it is, indeed, remarkable that commitment to this document has resulted in a number of successes in combatting Great Lakes problems. How the Agreements and the institutional framework have worked toward remediating some of the major problems related to human activity in the basin is assessed below within the discussion of each issue. Human Health It was concern over human health through the occurrence of major outbreaks of typhoid that led the two countries to ask the UC in 1912 to investigate the "pollution" of the lakes. Table II presents a statistical summary of typhoid mortality between 1913 and 1947 for the St. Clair/Detroit River area of the Great Lakes, the state of Michigan and the province of Ontario (10). These statistics clearly show a higher death rate for the Detroit/St. Clair region than for the rest of Michigan or Ontario up to about 1930. Since 1930 the problem has been eradicated although a significant drop had already occurred by 1920. This was accomplished largely through treating drinking water supplies by filtration and disinfection by chlorine and moving drinking water intakes to non-polluted Areas, It is interesting to note that the Commission's 1918 Report to Governments confirmed that transboundary pollution was, indeed, occurring and that it was "feasible and practicable, without imposing an unreasonable burden upon the offending communities, to prevent or remedy pollution in the boundary waters" (11). At the request of the two Governments, the Commission in 1920 drafted a "convention" which would accomplish this purpose. However, with the advent of chlorination of municipal water supplies and in the general belief that there was an inexhaustible supply of clean, fresh water to dilute all wastes, the expenditures of large sums of money on waste treatment facilities did not appear to be urgent. The proposed convention was never negotiated to conclusion. It would be almost another 30 years (1946) before the Commission was again approached by governments, this time to examine the pollution problems resulting from the new types and greater volumes of waste discharges by developing industrial complexes and accompanying growth and concentrations of population. Today the problem of human health is again high on the public agenda due to


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Great Lakes Water Quality - ACS Publications - American Chemical

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