More than 400,000 people who live in northwestern Ohio and southwestern Michigan were unable to use their tap water for three days this week due to algae blooms in Lake Erie.
An advisory against drinking or using the water was issued on the morning of Aug. 2 after tests at a treatment plant showed that microcystin levels were above the standard for consumption. Algae in Lake Erie is thought to be the reason behind the pollution.
A satellite image released by the National Oceanic and Atmospheric Administration showed a small but concentrated algae bloom centered right where Toledo draws its water supply, said Jeff Reutter, head of the Ohio Sea Grant research lab, as quoted by the Lansing State Journal. Although the bloom was actually smaller than in previous years, weather conditions meant that its position was very close to the water intakes, Reutter added.
The latest test results suggest that the contamination has probably dissipated to safe levels but Toledo Mayor D. Michael Collins said early on Monday that he would keep the advisory in place for now, pending further tests.
After Toledo residents were told not to drink, brush their teeth or wash dishes with the water, truckloads of bottled water were delivered from across the state. In addition, the Ohio National Guard used water purification systems to produce drinkable water, the Associated Press reported.
Local water distribution centers reopened at 8:00 a.m. on Monday morning.