DEC draft permit keeps Fairbanks wastewater discharge to the Tanana at 11.2 million gallons a day

The Alaska Department of Environmental Conservation is preliminarily proposing to keep the Fairbanks wastewater plant's discharge limit to the Tanana River at 11.2 million gallons a day, according to a preliminary draft permit the agency released Aug. 20. No permit is final. The notice opens a review period. That ceiling matches what DEC proposed in 2021 and is 40% above the 8.0 million gallons a day listed in the agency's 2015 preliminary draft for the same facility.

The permit covers secondary treated domestic wastewater from the plant jointly identified as the City of Fairbanks and Golden Heart Utilities, Inc., discharged at a fixed point on the Tanana. The Tanana drainage is the second-largest tributary system of the Yukon River and supports a personal-use salmon fishery managed by the Alaska Department of Fish and Game.

The parameters covered by the proposed mixing zone have changed. The 2015 draft listed ammonia, copper, total residual chlorine and whole effluent toxicity. The current draft, like the 2021 proposed final permit, lists total ammonia as nitrogen, copper, temperature and whole effluent toxicity.

A mixing zone is the stretch of river where numeric water quality limits may be exceeded during initial dilution. DEC says water immediately outside the zone must meet all criteria. Agency guidance says a mixing zone cannot preclude or limit commercial, sport, personal-use or subsistence harvest. An EPA review of Alaska's mixing zone rules states that long-term zones can leave localized areas of reduced water quality, contaminated sediments and degraded benthic habitat.

The notice contains no monitoring data and no analysis of effects on the river. Neither the City of Fairbanks nor Golden Heart Utilities has commented on the proposed limit. No response from Tanana River users or local watershed groups appears in the record.

Applicant review runs through 11:59 p.m. Sept. 2. After that, DEC will prepare a draft permit and fact sheet for a 30-day public comment period. Marie Klingman is the DEC contact.