Toxic Water in Toledo

algal bloom

A tow boat kicks up a wake full of green algae a few hundred feet from the city of Toledo’s Water Intake on Lake Erie on Monday, August 4, 2014. (Photo credit: The Washington Post/Getty Images)

The shutdown of Toledo’s water supply was one of the top environmental stories in the summer of 2014. What caused the toxic water? Could this happen again?

On the evening of Friday, August 1, 2014, chemists at Toledo’s Collins Park Water Treatment Plant took a water sample that read 0.6 for microcystin. A “microcystin” is a class of toxins produced by cyanobacteria, which can cause significant harm to human and animal health. In total, two samples exceeded the 1 microgram/liter standard. The reading triggered notification of the Ohio Environmental Protection (EPA). As a result, during the early morning hours of Saturday, August 2, residents receiving their water from the city of Toledo were advised to not drink nor even boil water from the tap. Residents found themselves scrambling for alternative water sources, some even traveling as far as Canada to find bottled water. The water-use restrictions remained in place until the morning of August 4, when the water again was deemed safe for consumption and use.

Microcystin is a toxin associated with algal blooms. The toxin can cause severe gastrointestinal symptoms such as nausea, vomiting, and diarrhea. It also can cause severe headaches, fever, and liver damage. Boiling water, which is a method commonly-used to decontaminate drinking water, is ineffective against microcystin. On the contrary, it only manages to concentrate the toxin.

What’s to blame for the sudden appearance of microcystin in Toledo’s water supply? The fault lies with an algal bloom in Lake Erie, which inundated the city’s water intake. In recent years, giant algal blooms have appeared in Lake Erie during the summer. Toledo has spent $3 million/year (in 2013 they spent $4 million) in an attempt to get the algae under control. The algal blooms are a consequence agricultural run-off. According to a report in The Wall Street Journal, “the Maumee River drains more than 4 million acres of agricultural land and dumps it into Lake Erie and the Port of Toledo.” Much of the land in northern Ohio is dedicated to crops, such as corn and soybeans, which require heavy loads of fertilizer.

In the 1960s and 1970s, Lake Erie and its surrounding riverways were something of a joke. (The Cuyahoga River in Cleveland actually caught on fire in 1969!) The implementation of the Clean Water Act (CWA) in 1970 helped to curtail some of the pollution that had so greatly affected the waterways of northern Ohio. While the CWA regulats point-source pollution, such as municipal sewage and industrial waste, it does not regulate non-point source pollution, such as runoff from agricultural fields. According to the National Oceanic and Atmospheric Association (NOAA), “Harmful algal blooms were common in western Lake Erie between the 1960s and 1980s … After a lapse of nearly 20 years, blooms have been steadily increasing over the past decade.”

This increased appearance of algal blooms is in part due to climate change. Longer, warmer summers provide algae with more time to build up. Warmer temperatures also significantly increase the incidence of heavy rainfall in the Upper Midwest. This increased rainfall causes more runoff from agricultural fields, increasing the amount of phosphorus and other excess nutrients in local waterways. Most of this material finds its way into Lake Erie.

Following the microcystin outbreak, the city of Toledo has implemented new practices, with the guidance of state and federal EPA officials, to prevent toxins from entering the water supply. Fighting algal blooms however, is an ongoing, and costly, battle, one that perhaps will never end.

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