Residents of Toledo, Ohio got a scare on Saturday when they were told to avoid water from the tap because toxins had contaminated the public water supply. The advisory affected some 400,000 residents “after tests at one treatment plant showed two sample readings for microsystin above the standard for consumption, possibly because of algae on Lake Erie,” the Associated Press reports. “City officials said consuming water containing algal toxins may result in abnormal liver function, diarrhea, vomiting, nausea, numbness or dizziness,” the Wall Street Journal reports.
“The city also said not to boil the water because that would only increase the toxin's concentration. The mayor also warned that children should not shower or bathe in the water and that it shouldn't be given to pets,” the AP reports. “Worried residents told not to drink, brush their teeth or wash dishes with the water waited hours for deliveries of bottled water from across Ohio as the governor declared a state of emergency.” The National Guard has been delivering bottled water to residents in the area.
Here’s how the water contamination may have occurred from the Journal:
Lake Erie, which is a source of drinking water for the Toledo water system, may have been impacted by a harmful algal bloom, according to the city. These blooms happen when there are excess levels of nitrogen and phosphorus in lakes and streams, which can come from runoff of over-fertilized fields and lawns, from malfunctioning septic systems and from livestock pens.