A handout photo shows the algal bloom in Lake Erie on July 31.
The Toledo water plant’s increased use of chemicals to treat the water for microcystin toxin is responsible for unusual characteristics city customers may be noticing in the water, a Collins administration spokesman said Saturday.
The statement from Lisa Ward also said that the microcystin level in treated water at the Collins Park plant approached, but did not quite reach, the 1 part per billion threshold at which a do-not-drink order would have been issued before chemical treatment increased and cut the reading by more than half.
The sample that returned a 0.972 part per billion test result was taken Friday. Increased use of chlorine treatment may cause a slight chlorine odor, Ms. Ward said, while increased alum in the treated water is to blame for a “harmless” surface film people may observe on water in cups or containers.
“While the water is safe to consume, we wanted the public to be aware that we are dealing with an algal-bloom situation and that since a test showed above .5 parts per billion, the Ohio EPA has been notified,” Ms. Ward wrote. “We will continue to closely monitor the level of microcystin and the levels of chemicals needed to provide safe drinking water.”
Larry Vasko, deputy commissioner of the Lucas County Health Department, said the 0.456 part per billion test result obtained after stepped-up water treatment came from samples tested Saturday afternoon.
At that time, he said, raw-water samples from Toledo’s intake crib tested at 50 parts per billion for microcystin, a toxin emitted by blue-green microcystis algae that have bloomed in western Lake Erie for several weeks.
Of the 33 distribution samples that were taken, all were clear, Ms. Ward said. Eighteen were below a 0.30 parts per billion threshold, which means “nondetect,” and “of the remaining ones they were still within the safe range.”
The reason for sampling the 30 random sites from around the city, she said, is that any readings at 0.50 parts per billion or more have to be reported to the Ohio Environmental Protection Agency.
Tests taken on the evening of Aug. 1 and early morning of Aug. 2 at the Toledo water plant showed microcystin exceeding 1 part per billion in the treated water, which prompted officials to issue a do-not-drink order that remained in effect until midmorning Aug. 4.