A water main break caused more than a half-million gallons of chlorinated water to rush into Gilleland Creek, Pflugerville Wednesday afternoon, causing some smaller fish to die.

A city contractor was drilling into Isle of Man Road about 3 p.m. Wednesday to get a core sample of the road when the drill hit an 8-inch line, city spokesperson Terri Toledo said. Windermere Utility Company immediately turned off the water supply once it received information on the water main break, but not before 560,000 gallons of drinking water had leaked into the creek.

City Stormwater Specialist Roberto Vega said some small perch and minnows died due to the small concentration of chlorine in the drinking water. But bass, turtles and other wildlife did not seem to be affected as of yet by the chlorination, he said.

Texas Commission on Environmental Quality standards state that all drinking water should be treated with a small amount of chlorine, according to a WUC release.

TCEQ and Texas Parks and Wildlife officials were on scene Thursday to investigate. The creek remained open to the public.

According to Statesman on September 24th, 2015