UPDATE 7/17/25 5:49 PM: As of Thursday evening, water samples show that the toxin levels in Mattoon's water supply are at 0.058 parts per billion, a decrease from 0.215 parts per billion in Wednesday's test.
These results qualify as a non-detect reading, but the IEPA is still recommending that Mattoon stays under a do not drink order out of caution.
Another round of testing is scheduled for tomorrow, and the city has started a controlled flush of the water system that will continue through the night.
UPDATE 7/17/25: As of midday Thursday, Mattoon remains under drinking water restrictions due to unacceptable toxin levels caused by an algal bloom at Lake Paradise.
WAND spoke with Public Works Director Dave Clark, who stated that while the water is still unsafe for consumption, it is harmless to come into contact with it.
“You can shower, wash your hair, wash your clothes, your hands. You can’t get it through your skin. You have to ingest it by drinking it,” said Clark.
MATTOON, Ill. (WAND) - Further testing showed toxin levels are decreasing in Mattoon's water supply after reissuing a "Do Not Drink" order.
The City of Mattoon said in a July 16 Facebook post that the IEPA sampled the water Wednesday, showing a decrease in contaminants.
Results had algal bloom neurological toxin levels at 0.215 parts per billion, down from 0.38 parts per billion found in previous testing.
While the city said the downward trend is encouraging, regular sampling and testing will continue before the "Do Not Drink" order is lifted.
The order will remain in place until Mattoon receives at least two consecutive safe test results as recommended by the IEPA.
The next test is scheduled for July 17.
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