CHICAGO, Aug. 4 (Xinhua) -- A ban that left about 500,000 Ohio and Michigan residents scrambling for drinking water has been lifted, Toledo's Mayor Michael Collins announced Monday morning at a news conference.
Tests showed that toxins were no longer at dangerous levels from algae on Lake Erie, the mayor's office said. The announcement came after people in northwestern Ohio and southeastern Michigan had been told not to drink tap water on Saturday because of toxins contaminating Lake Erie.
Ohio Governor John Kasich declared a state of emergency in three counties early Saturday after two water samples from a Toledo treatment plant tested positive for microcystin, a toxin possibly caused by an algae bloom in Lake Erie.
News of the contaminated water spread quickly throughout the area, sending residents flocking to Toledo shopping malls in search of fresh water. In response to the water shortage, the Ohio National Guard and other state agencies have been delivering bottled water to the residents over the weekend.
Officials said that rapid increases in algae levels are caused by high amounts of nitrogen and phosphorous, which could come from runoff of excessively fertilized fields or from malfunctioning septic systems or livestock pens.
Chicago also did testing this weekend on its water following the finding of toxins in Lake Erie. The water samples collected from Lake Michigan and tested overnight showed none of the toxins found in Toledo, Ohio, according to a file released Sunday by Chicago's Department of Water Management.