More than 500 fish died following a wastewater spill into Gilleland Creek in Pflugerville earlier this week, according to numbers from the Texas Parks & Wildlife Department.

The city of Pflugerville on March 4 discovered a a mechanical failure of a dechlorination pump at the Gilleland Creek Wastewater Treatment Plant, according to a city news release. It was determined approximately 3.4 million gallons of treated, chlorinated wastewater was discharged into Gilleland Creek.

“The city notified appropriate regulatory entities of the chlorination issue including the Texas Commission on Environmental Quality and [TPWD],” the news release stated.

TPWD was on site March 4 and the city reported Gilleland Creek returned to normal chlorination levels that day.

In all, 544 fish died in Gilleland Creek after the wastewater discharge, according to figures from TPWD.

That includes 158 channel catfish; 116 longear sunfish; 88 gray redhorse; 79 blacktail shiner; 63 Guadalupe bass; and reported deaths of eight other types of fish—including 2 largemouth bass.

In its March 4 news release, the city advised residents to avoid contact with waste material, soil or water in the area affected by the spill.

Additionally, anyone with private drinking water supply wells located within half a mile of the spill site should use only water that has been distilled or boiled for at least one minute for all personal uses including drinking, cooking, bathing and tooth brushing. Anyone living within half a mile of the creek with a private well should have their well water tested and disinfected prior to discontinuing distillation or boiling, per the release.