Navajo Tribal Utility Authority agreed to a Partial Consent Decree requiring approximately $100 million in wastewater treatment upgrades at Chinle, Kayenta, and Tuba City facilities in Arizona, resolving documented permit violations for discharging inadequately treated wastewater and failing to properly operate and maintain facilities serving approximately 20,000 Navajo Nation residents.

Navajo Tribal Utility Authority — $100 Million Wastewater Treatment Consent Decree (2024)

Outcome: Navajo Tribal Utility Authority agreed to a Partial Consent Decree requiring approximately $100 million in wastewater treatment plant upgrades and system improvements at its Chinle, Kayenta, and Tuba City facilities in Arizona, resolving documented Clean Water Act violations for regularly discharging inadequately treated wastewater and failing to properly operate and maintain facilities serving approximately 20,000 Navajo Nation residents.

The Navajo Tribal Utility Authority (NTUA), the tribally chartered utility providing water, wastewater, electric, gas, and telecommunications services to Navajo Nation communities, operated wastewater treatment facilities at Chinle, Kayenta, and Tuba City, Arizona that failed to consistently treat wastewater to the standards required by their Clean Water Act NPDES permits. EPA inspections and reports submitted by NTUA documented regular discharge of wastewater that had not been treated to required permit standards, as well as failures to properly operate and maintain the facilities' sewer systems — resulting in sewage spills into local waterways and the surrounding environment.

The Partial Consent Decree, announced January 10, 2024, required NTUA to implement short-term improvements to the performance of existing treatment plants, construct new treatment plants over a longer-term schedule, improve operations and maintenance programs across all facilities, and conduct comprehensive study of the sewer system piping at each facility location to identify all pipe defects and develop a rehabilitation plan. Total required investment is approximately $100 million. The decree was characterized as "partial" because enforcement obligations for additional NTUA facilities may be addressed in subsequent agreements.

The Navajo Nation faces some of the most severe water and wastewater infrastructure deficits of any community in the United States, with large portions of the reservation lacking access to municipal water and wastewater services entirely. The communities served by the three facilities — Chinle, Kayenta, and Tuba City — are among the more populous centers of the 17.5-million-acre reservation, and the $100 million consent decree represents a major federal investment in Navajo wastewater infrastructure through the consent enforcement mechanism.

Primary Source: Navajo Tribal Utility Authority Agrees to $100 Million in Wastewater Treatment Improvements | US EPA