Twenty-four hours later, Austin Water says it's still unsure when the odd smell coming from tap water in certain parts of the city will dissipate. The water utility said yesterday morning it would resolve the issue within a day, but that estimate has come and gone and it's unclear what the timeline is going forward.

Friday morning, Austin Water spokesperson Ginny Guerrero told KUT the utility did not have an update on the water quality. The utility is still putting activated carbon into the water to help resolve the odor issue, and the water is still safe to drink, she said. Guerrero did not have a timeline for when the water would return to normal.

KUT's Nathan Bernier speaks to KUT's Mose Buchele about zebra mussels

Thursday afternoon, Austin Water said the culprit was most likely the presence of zebra mussels in a waterline at the Ullrich Water Treatment Plant along the Colorado River.

Zebra mussels were first spotted in Lake Austin a year ago. The mussels clog intake pipes and pose a serious threat to the city's water treatment plants. Last year, the city said there is no way to safely get rid of zebra mussels without damaging the surrounding ecosystem.