Alaska’s coastal communities are home to more than a third of the U.S. wastewater plants still allowed to treat their sewage at the lowest and most basic level. But six cities in Southeast Alaska, including Wrangell, may soon have to invest in improvements to better clean their wastewater before discharging it into the ocean.
That is the message from draft permits that have been released or are to be released by the Environmental Protection Agency, which has determined that too much bacteria is going from the communities into marine waters.
The agency the first week of May issued a draft permit for the Haines Borough’s wastewater plant that calls for disinfection of bacteria in the treated discharge. As of now, there is no disinfection at the Haines plant, and its discharges contain high levels of fecal coliform and enterococcus bacteria, common pollutants in sewage, the EPA said. To meet state water-quality standards, the plant relies on a large “mixing zone” in Portage Cove.
Mixing zones are defined by the Alaska Department of Environmental Conservation as areas “where a permitted wastewater discharge undergoes initial dilution,” and where pollutant levels may exceed water-quality standards.
According to EPA’s analysis, the mixing zone used in Haines is no longer adequate. Wrangell discharges its wastewater into Zimovia Strait, where it is mixed and diluted by the strong flows.
A similar disinfection requirement is contained in a new draft permit issued in October for the wastewater treatment plant at Wrangell. The borough recently received a new cost estimate for adding a chlorine disinfection process to its wastewater discharge — about $12.5 million for construction, plus ongoing operating costs.
“This is considerably more than what we were planning on,” Borough Manager Jeff Good said last month.
Under the draft permit, Wrangell would have five years to meet the higher standards for its water discharge.
Yet to come, EPA said, are new drafts for Skagway, Sitka, Petersburg and Ketchikan. All six Southeast sites are operating on permits that were issued more than 20 years ago and have been periodically extended.
The six communities, all discharging into fast-moving marine waters, are among a select few in the nation that have municipal wastewater plants allowed to use mere primary treatment on the wastes they process, according to EPA. Primary treatment screens out solids, and all six plants rely on large mixing zones in their discharge areas.
The vast majority of publicly operated wastewater plants in the nation are required to do at least a second level of treatment, said Suzanne Skadowski, a spokeswoman for EPA’s Seattle-based Region 10 office. Secondary treatment employs bacterial and additional physical separation to remove about 85% of contaminants; it is now standard practice at most plants. Some plants use a third level of treatment, which uses more advanced methods to remove contaminants.
In all, 24 plants around the nation are exempted from the secondary-treatment requirement, and nine are in Alaska — Pelican, Whittier and Anchorage, plus the six in Southeast that could soon face new permit requirements.
Of the nine Alaska plants with waivers, the biggest by far is the wastewater treatment facility operated by the Anchorage Water and Wastewater Utility. The plant, which serves most residents of the state’s largest city, discharges into the silty and swift-moving waters of Cook Inlet. Unlike the six Southeast Alaska sites, the plant uses disinfectant — chlorine — as part of the treatment before wastewater is discharged into the inlet.
The plant is operating with a permit issued in 2000 and continued through administrative action, Skadowski said, adding that the federal agency is working with the state and Anchorage to update data on the facility’s operation and its water quality.
The Alaska Beacon is an independent, donor-funded news organization. The Sentinel contributed reporting to this story.
Reader Comments(0)