EPA lifts E. coli boil water advisory for Santee Sioux Nation, manganese advisory remains in place
The U.S. Environmental Protection Agency (EPA) Region 7 has lifted the boil water advisory for the Santee Sioux Nation’s public water system near Niobrara, Nebraska, after confirming the system’s drinking water is now safe from E. coli contamination. However, the manganese advisory for the same system remains in effect, and residents are advised not to drink tap water until further notice.
The E. coli advisory, issued on Sept. 5, 2025, was rescinded after EPA and Tribal officials implemented a series of corrective actions, including installation of a new disinfection pump, system flushing, and on-site technical assistance to adjust chlorine dosing. Recent testing confirmed the absence of total coliform and E. coli, verifying that the disinfection system is functioning properly.
“I am pleased to announce that comprehensive measures have been taken by Tribal leadership and EPA to ensure the safety and quality of the water supply for the Santee Sioux Nation,” said Jim Macy, EPA Region 7 administrator, in a press release. “Your health and safety remain our top priorities, and we are committed to ongoing monitoring to prevent future occurrences.”
To maintain compliance with the Safe Drinking Water Act, EPA and the Tribe have also signed an order on consent outlining additional steps, including daily chlorine monitoring and planned rehabilitation of two drinking water wells this fall to reduce bacterial growth and lower manganese concentrations.
In a follow-up clarification, EPA Region 7 emphasized that while the E. coli boil water advisory has been lifted, the manganese advisory remains active. Elevated manganese levels continue to exceed EPA Health Advisory limits, prompting the Tribe to continue distributing bottled water for drinking and cooking. Tap water remains safe for bathing and cleaning purposes.
The well rehabilitation project, expected to begin later this year, aims to improve overall water quality and support long-term compliance with federal drinking water standards.