How Clean is Our Bay?

GT County's drinking water comes from East Grand Traverse Bay, but two areas along its shores are on the state's impaired water list. A study is underway to find out what pollutants are there, where they're coming from, and – before the study ends in 2011 – what can be done to stop them.

TRAVERSE CITY ­- In the summer, Grand Traverse Bay's pristine, blue, sparkling waters present the perfect venue for swimming, boating and other recreational activities.

Recent watershed studies show that the Bay's shoreline is meeting most recreational standards; however, upland waters are showing signs of stress and human pollutants.

Enter the Watershed Center Grand Traverse Bay and the Water Quality Program at Michigan State University (MSU). The two have collaborated to study the impact of pollutants on the natural waters of Grand Traverse County.

Their joint "Investigation of Water Quality in and Source Tracking at Grand Traverse Bay and Mitchell Creek" began on June 24, 2009. Just one report has been written to date, but "eventually the results will be disseminated to local officials in an attempt to help inform and direct necessary changes that reduce the bacterial loads entering the Grand Traverse Bay," says Marc Verhougstraete, Research Assistant for MSU.

So what has the investigation found so far? Bacteria levels in Mitchell Creek are much higher than those detected in the Grand Traverse Bay. While human fecal matter was detected in Grand Traverse Bay, the Traverse City State Park beach almost always meets Michigan's Escherichia coli (E. coli) recreational water quality standards. (The Michigan E. coli standard for total body contact states that a daily average of three samples may not exceed 300 E.coli/100 ml of water.)

"Mitchell Creek has specific places that are impacted by the human fecal contamination," says Verhougstraete, "and others that have relatively low bacterial concentrations for an urban system."

What is the cause of this creek water contamination? "Land use has a significant impact on microbial water quality in Mitchell Creek," says Verhougstraete. The study also points out that heavy rain and other types of precipitation impact the water quality.

The major players in this watershed study include Michigan State University's Water Quality, Environmental, and Molecular Microbiology Laboratory, The Watershed Center Grand Traverse Bay, and Grand Traverse County Health Department.

Why did these groups combine forces? "The study stemmed from multiple grants aimed at protecting, improving, and monitoring water quality in the Grand Traverse Bay Watershed," says Verhougstraete. "Water quality stakeholders in the Grand Traverse Bay area are very proactive when it comes to water quality," he says. "Thus, identifying the source of elevated bacterial levels was a very important objective in this study."

While the Grand Traverse Bay waters meet most recreational water standards, "the upland waters are showing signs of stress and human pollution inputs, which eventually make their way to the Grand Traverse Bay," says Verhougstraete.

Human fecal pollution has been detected throughout Mitchell Creek and at Traverse City State Park. "This draws significant attention to the need for wastewater infrastructure updates and routine checks," says Verhougstraete. "Additional work is ongoing to pinpoint illicit wastewater discharges and leaks into storm drains and surface waters."

The watershed research team hopes these findings help keep pristine waters in the Grand Traverse Bay a reality. This can be accomplished by providing critical information to local decision makers.

"Keeping the Grand Traverse Bay waters clean will require changes on all levels, personal and political," says Verhougstraete. BN

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