The state of Alaska is advancing a controversial proposal that would allow, in some cases, an elevated amount of wastewater pollution to enter fish spawning areas.
State environmental regulators said they wouldn't allow increased pollution where scientific studies showed it could harm spawning fish or their habitat in streams and rivers.
But Juneau environmentalists and fishermen are asking where the state will draw the line on often-conflicting scientific evidence on what is harmful. They also decry the state's decisions to hold hearings on its proposal - including one in Juneau tonight - in the middle of the state's commercial fishing season.
"Nobody can comment," said Paula Terrel, Southeast director of the Alaska Marine Conservation Council. "The majority of the fishermen don't have a clue what's happening because they are fishing and will be, in varying degrees, until October."
Comments are due on the proposal Sept. 10.
The proposed rule would replace the current ban on mixing zones in Alaska's freshwater spawning areas. Mixing zones are areas in a water body where wastewater discharge is allowed to exceed pollution limits while blending with uncontaminated water for dilution.
Mixing zones have always been controversial in Alaska, said Nancy Sonafrank, water quality standards section chief for the Alaska Department of Environmental Conservation.
Mixing zones are commonly used in Alaska by sewage treatment plants, seafood processors and other industries. All three of Juneau's sewage treatment plants - discharging to the Mendenhall River, Gastineau Channel and Auke Bay, where spawning does not occur - are allowed to use mixing zones.
The only other state with a prohibition on mixing zones specifically in fish spawning areas is Minnesota, Sonafrank said.
Alaska's prohibition was adopted in 1997 after advocacy groups lobbied for stricter regulations, she said.
But since then, some problems have developed with sewage plants and placer miners who are facing expensive treatment of pollution that won't actually harm spawning, she said.
Terrel responded, "If that's a problem, they should keep the (current) language .. but allow for exemptions."
Sonafrank sees little potential use of mixing zones in Southeast's salmon streams in the near future, but that does not allay concerns from local environmentalists and fishermen.
Some worry that the proposal could be used by Coeur Alaska to address total suspended solid and aluminum discharges from its proposed Kensington Mine, though a federal regulator said that will not be allowed.
"We don't see it impacting us at this time," said Rick Richins, Coeur Alaska's Kensington Mine project director.
Others say Alaska officials appears to be mimicking British Columbia's regulatory approach to protecting wild salmon and the environment.
The British Columbia provincial government is fast-tracking a proposed multi-metal mine in the Taku River watershed, which includes a mixing zone for wastewater discharges to the Tulsequah River.
The Environmental Protection Agency, Juneau city officials and state legislators are protesting the Canadian government's handling of the Tulsequah Chief project because of environmental and economic risks it could pose to Juneau-based gillnetters in Taku Inlet.
In a recent letter to Canadian officials, Alaska regulators noted the presence of rearing fish in streams near the mine's proposed mixing zone that are "particularly sensitive to water quality."
Yet, Alaska's mixing zone proposal "takes us down a path that British Columbia is going. It doesn't seem right," said Chris Zimmer, a Juneau activist with the Transboundary Watershed Alliance.
The proposed mixing zone rule is the first in a series of proposed water quality changes to be announced by the state Department of Environmental Conservation this year, officials said.
Elizabeth Bluemink can be reached at email@example.com.