The city of Pueblo had an “unplanned” discharge of untreated sewage into the Arkansas River near Confluence Park on Thursday, according to a news release by the city.

Crews were able to stop it by 11:45 a.m., possibly contaminating the area for the next 48 to 72 hours, Director of Wastewater Andra Ahrens stated in the release.

Officials warn Avondale, Boone, Fowler, Manzanola, Rocky Ford, Swink, La Junta and Las Animas could be affected.

The leak occurred in a wastewater pipe inside of a stormwater pipe. The pipe had a hole patched with concrete several years ago. “Over time the concrete slipped from the hole,” according to the release, and the pressure of the sewer pipe caused untreated wastewater to flow through the hole and into the river.