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Thom Cmar’s Blog

Why Do Great Lakes Beaches Close? The Answer Begins In Our Sewers

Thom Cmar

Posted July 28, 2010

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Chicago got 7 inches of rain last weekend.  All hell broke loose

Flooding occurred throughout the city and suburbs, and counties throughout Chicagoland have been declared disaster areas.  In Chicago itself, the Metropolitan Water Reclamation District was forced to reverse the flow of the Chicago River into Lake Michigan to prevent even more flooding in the city.  As a result, the Chicago Park District banned swimming at Chicago area beaches.

Why is there a connection between heavy rains and swim bans at beaches?  Answering this question requires understanding how our sewers work – and why the Great Lakes region has the most polluted beaches of any region in the country.

In 2009, as many as 10% of Great Lakes beachgoers reported getting sick after swimming at open beaches.  U.S. Great Lakes beaches suffered 3,300 days of cumulative closings and advisories, with a pollution rate that is twice the national average.  Overall, 13% of the samples collected at 408 Great Lakes beaches exceeded daily maximum standards for E. coli.  60 of those beaches, across all 8 Great Lakes states, recorded beachwater samples exceeding daily maximum E. coli standards more than 25% of the time.

Pollution at our beaches not only makes beachgoers sick, it also has a huge economic impact.  Great Lakes beaches help support a vital tourism economy.  Closing a single beach to swimming can cost the local community as much as $37,000 per day.

These findings, and a great deal of additional data and analysis, are contained in the 20th annual release of NRDC’s report, Testing the Waters: A Guide to Water Quality at Vacation Beaches, that compiles and analyses data on bacterial pollution at beaches across the United States.  This morning I’ll have the opportunity to help with the Chicago unveiling of our 2010 Great Lakes edition.

Aging and poorly designed combined sewage and stormwater systems contribute much of the problematic pollution mucking our waters and recreational beaches.  Notably, combined sewer overflows, or CSOs, are concentrated heavily in the 8 Great Lakes states when compared to the rest of the country. Combined sewer systems collect rainwater runoff, raw sewage, and industrial wastewater in the same pipe and, under normal conditions, transport this witches’ brew to a water treatment plant.  But under storm conditions with heavy rainfall, the system becomes backed up and overflows directly to nearby streams, rivers, and lakes (known as a CSO event).  Beaches in areas with this outdated combined sewer infrastructure are generally the ones with the thickest bacterial frappe off of their shores. 

Global climate change will only exacerbate this problem, making CSO events both more common and more severe.  Research conducted by the University of Illinois and Texas Tech University for the Chicago Climate Action Plan suggests that precipitation could increase by as much as 20 percent by the end of the century.  The same research shows that the frequency of extreme storm events, in which more than 2.5 inches of rain fall within a 24-hour period of time, could increase 50 percent by 2039 and 80-160 percent by the end of the century.

Invasive species such as zebra and quagga mussels have also compounded the problem.  By feeding on plankton and other microorganisms at the base of the food chain, invasive mussels have extensively cleared Great Lakes water.  Consequently, sunlight can penetrate the waters more deeply, encouraging aquatic plant growth on the Lake floor, often in the form of the mat-forming green algae CladophoraResearch shows that these algae mats serve as breeding grounds for E. coli.  The looming threat of Asian carp (which have similar filter feeding habits to zebra and quagga mussels but are enormously bigger and consume vastly larger amounts of plankton) migrating to the lakes will only further exacerbate this attack on the base of the Lakes’ food chain.

The good news in the Testing the Waters report is that there are a number of steps we can take to help solve these problems and improve our water quality.  For starters, there is a massive need for additional public investments to fix our outdated sewer infrastructure.  To invest the money wisely, we need to target Green Infrastructure development.  Green Infrastructure is the use of natural systems, such as wetlands, street trees, other types of vegetation and green space, and pervious pavement to soak up stormwater and filter out the pollutants it contains.  These methods reduce the amount of water that flows into the traditional, “hard infrastructure” system of pipes, pumps, storage tunnels, and treatment plants that is costly to build and maintain.  By filtering stormwater and reducing the load on wastewater treatment plants, green infrastructure can abate CSO events, improve water quality, save energy, and promote more aesthetically pleasing neighborhoods. Moreover, green infrastructure provides an array of economic benefits, from increasing property values and creating green jobs, to reducing pollution (thus lowering associated public health costs) and easing soaring temperatures (thus lowering utility expenses).

Green Infrastructure can also be deployed as part of a solution to the Asian carp problem.  The only reliable way to keep the carp out of the Great Lakes is to physically separate the Lakes from the Mississippi River.  A well-planned permanent separation between the two watersheds should also be combined with aggressive deployment of Green Infrastructure, which would not only mitigate the water quality and flooding impacts of separation, but also actually improve water management in the Chicago waterway system and quality of life for the surrounding communities.  Moreover, this permanent separation will only be possible if the Metropolitan Water Reclamation District agrees to meet upgraded water treatment standards that are long overdue.  Combined, all of these steps can help make both the Chicago River and Chicago’s beaches cleaner while addressing an urgent threat to the economy and ecology of the Great Lakes from the Asian carp.

Hopefully the Great Lakes Restoration Initiative and the projects funded by it, from beachwater sampling to nearshore habitat restoration, will be a first step in addressing the contamination of our Great Lakes beaches.  In addition, President Obama’s announcement of a new national oceans and Great Lakes policy last week will facilitate better protection of our coastal ecosystems. Still, much more needs to be done.  The 2010 Testing the Waters report highlights the potential for investment into more modern and sustainable infrastructure that will improve the health and vitality of our Great Lakes waters and, in doing so, help build a new basis for our region to prosper.

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