Navajo Nation utility will upgrade or replace wastewater plants under EPA agreement

Navajo Tribal Utility Authority has agreed to a partial consent decree with the U.S. Environmental Protection Agency to improve wastewater treatment at its Chinle, Kayenta and Tuba City facilities.

These treatment upgrades will cost up to $100 million and will improve compliance with the facilities’ Clean Water Act permits. The upgrades will affect about 20,000 people across four communities within the Navajo Nation.

“The settlement negotiations that let to the (agreement) were conducted in a professional, amicable and respectful manner,” said NTUA General Manager Walter Haase. “The end result is an incredibly comprehensive and detailed agreement that will ultimately benefit the Navajo people and the communities that we serve, the environment and NTUA itself.”

Based on EPA inspection findings and reports submitted by NTUA, the U.S. stated in its original complaint that NTUA violated its Clean Water Act permits by regularly discharging wastewater that had not been treated to the required standards, and by failing to properly operate and maintain the facilities’ sewer systems to prevent sewage spills.

NTUA said the 50-year-old wastewater facilities serve about 4,060 wastewater customers and have “at times” discharged treated wastewater that has exceeded certain permit limits.

These wastewater treatment facilities were built by federal agencies in the late 1960s and early 1970s and turned over to NTUA for operation.

Agreement addresses water quality, infrastructure

The consent decree was put together after a year of negotiations over the measures NTUA will put in place. It requires NTUA to improve the performance of its existing treatment plants in the short term, and to construct new treatment plants over the longer term, according to EPA.

Under the terms of the agreement:

• NTUA will work to relocate the new Tuba City facility from its current footprint to mitigate risks associated with the Moenkopi Wash’s continued erosion toward the facility and to decrease the chance of a catastrophic release of sewage.

• NTUA must improve its operation and maintenance of the facilities and study its sewer system piping to identify all defects and plan for their repair. Negotiations on terms of the sewer system repair plan will happen at a later date.

The settlement also aims to ensure the affected communities have a voice in the improvement process by requiring NTUA to seek public comments on various aspects of its work plans.

“The Navajo Tribal Utility Authority failed in its responsibility to address the untreated sewage being discharged from three of their wastewater facilities,” said David M. Uhlmann, EPA assistant administrator for the Office of Enforcement and Compliance Assurance. “The work under this partial settlement will result in cleaner and healthier water for these tribal communities within the Navajo Nation.”

Excess pollutants in treated wastewater can harm fish and other aquatic life, create algal blooms and prevent surrounding communities from safely using the water. Spills and overflows from sewer pipes can pose a public health risk by potentially exposing people to untreated sewage, which may contain viruses, bacteria, or parasites that can make people ill, according to the EPA.

Haase said the measures NTUA will put in place because of the agreement are already under way. Raw sewage collected from the Chinle, Kayenta and Tuba City is subjected to “rigorous physical, biological, and chemical treatment process through a series of large ponds at each site.

“NTUA is not sitting on its hands waiting for court approval of the PCD,” said Haase. “I already instructed my staff months ago, when the final PCD was taking shape, to begin to implement the requirements to improve these facilities.”

Drafting the compliance plans and the concept solution was started with the administrative order compliance years ago. All sites are in design and engineering stage, and construction of the Chinle wastewater treatment facility will be completed by February 2027 and fully operational the following year.

The Kayenta facility will be constructed by February 2027 and fully operational in January 2028, according to Deenise Becenti, NTUA Government and Public Affairs manager.

Work on the Tuba City site will not start until a land withdrawal is approved by the Navajo Nation. The design is over 80 percent complete, and construction will begin after plans are approved and a construction contractor is acquired.

“For close to six years NTUA has been working with the respective tribal communities seeking permission for acreage,” Becenti wrote in an email to The Arizona Republic. “Once land withdrawal is approved, there will be other numerous steps that would need to be approved and completed.”

She also said NTUA is concerned that it's not possible to consistently achieve full compliance with all the discharge permit limits at the existing facilities, even with the interim upgrades.

"Compliance will be achieved with the replacement plants, similar to the Window Rock wastewater treatment plant," Becenti said.

Finding the funds for the work

To support its wastewater treatment programs, NTUA receives grant funding from various federal agencies — including the EPA, the Indian Health Service, and the Department of Agriculture — and from recent federal appropriations, including the Bipartisan Infrastructure Law and the American Rescue Plan Act.

Federal grants from these and other sources are projected to cover the majority of the $100 million cost expected under the consent decree, according to EPA.

NTUA will invest $205 million to improve the treatment both in short term and long term, including training and oversight of employees in its water division.

“The $68.9 million received in federal grants is not sufficient to cover the shortfall of the $136.6 million for interim upgrades and replacement treatment plants,” according to NTUA. “NTUA is actively investigating all available options to secure funding for that expected shortfall including but not limited to grants, loans, and other potential sources of financing necessary to fulfill the EPA-required provisions in the PCD.”

The matter is being handled by the U.S. Department of Justice, in conjunction with the EPA. The Navajo Nation Environmental Protection Agency actively participated in settlement negotiations leading to the Partial Consent Decree.

“Today’s action shows our commitment to prioritize public health and environmental protection for communities throughout the nation, including members of tribal communities often disproportionately burdened by pollution,” said Amy Miller, EPA’s Enforcement and Compliance Assurance Division Director for the country’s Pacific Southwest region. “By partnering with tribal governments to enforce federal and tribal pollution laws, we can protect public health and ensure communities have access to clean waterways.”

Arlyssa Becenti covers Indigenous affairs for The Arizona Republic and azcentral. Send ideas and tips to arlyssa.becenti@arizonarepublic.com.

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This article originally appeared on Arizona Republic: Navajo Nation utility to upgrade wastewater plants under EPA decree