Mattoon Vigilantly Ensures Safe Drinking Water After Last Year’s Algae Bloom Alert

MATTOON, Ill. — In the wake of the concerning algae blooms that emerged nine months ago, rendering Mattoon’s water temporarily unsafe, the city remains vigilant in its efforts to ensure water safety for its residents.

Through a recent update on Facebook, the city announced its ongoing collaboration with the Illinois Environmental Protection Agency to routinely test the drinking water. This proactive measure follows the initial discovery of algae blooms on July 10, 2025. Since July 16, the treated tap water has consistently shown undetectable levels of microcystin, affirming the effectiveness of the current treatment processes at the local water plant.