The toxin concentration of western Lake Erie water near Toledo’s water system intake crib fell back down to a nondetectable level Thursday, meaning it is 0.3 parts per billion or less.

Scientists have said anything 0.3 ppb or less is considered nondetectable because 0.3 ppb is the smallest reading that can be reliably made with the use of modern technology.

The city said the lack of toxin microcystin has prompted it to put the needle for its online dashboard back into the “Clear” area. To view the dashboard, go online to toledoblade.com/​drinkingwater.

There also is no sign of the toxin in treated tap water, the city said.

Microcystin was detected in the lake water for the first time this year on July 27. Since then, the city has been conducting daily tests for the toxin and has adjusted the water-quality dashboard status accordingly.

First Published August 7, 2015, 4:00 a.m.