Norwalk's drinking water remains safe, but officials aren't declaring victory yet as they battle a harmful algal bloom in the city's Upper Reservoir.
Test results released Tuesday showed 22 parts per billion of microcystin toxin, up from an initial result of 10 parts per billion. The EPA's limit for recreational use is 6 parts per billion, said Josh Snyder, public works director for the city of Norwalk.
Snyder said the city has been attacking the blue-green algal bloom with copper sulfate. Residents are still being warned not to let pets drink from the Upper Reservoir.
Snyder said that while the city is taking the problem seriously, it does not draw drinking water from the Upper Reservoir. Tests taken of the city's treated water has not shown any algal toxins, he said.
Snyder explained that Norwalk has an Upper Reservoir, a Memorial Reservoir and a Lower Reservoir. Drinking water is drawn from the Lower Reservoir, which is frequently treated with copper sulfate to keep an algal bloom problem from arising, he said.
When the Upper Reservoir overflows, it goes into Memorial Reservoir. Water also can be piped from the Upper Reservoir to Memorial. Memorial water can be piped into the Lower Reservoir, or it can overflow into Norwalk Creek, which goes into the Huron River, Snyder explained.
While the city is confident it can keep the Lower Reservoir from having an algal bloom problem, it can also change its treatment process if necessary, Snyder said.
Also, the city has an arrangement to obtain water from Northern Ohio Rural Water in an emergency, he said.
A spokeswoman for the Ohio EPA, Dina Pierce, said Tuesday her agency is working with Norwalk to track what's going on.
"We're actually working really closely with them," Snyder said. "They actually sent somebody yesterday afternoon to look at it."