53°

Mixing zones - areas in a water body where pollution discharges exceeding water quality standards are allowed to blend and dilute with clean water - are permitted by state law in areas outside of spawning zones.

They are used by nearly 300 wastewater treatment plants, numerous seafood processors and three mines, including Admiralty Island's Greens Creek Mine, state officials said Monday.

Some environmentalists and fishermen reacted with caution to the state's announcement.

The key provisions with the new version of the mixing zone regulation are:

• It allows companies to apply for a waiver of the ban on mixing zones in spawning areas. They were not allowed to do so previously.

• It withdraws a provision in state law that allows the Department of Environmental Conservation to issue an order approving a mixing zone without public comment.

• It extends the ban on mixing zones to spawning areas in lakes, which are not covered by existing law.

State regulators came under criticism last year due to their bid to lift the ban. About 600 people commented, most of them opposed.

"Many of the comments opposed mixing zones in concept, suggesting that they were illegal, irresponsible, or both," said Lynn Kent, Water Division director for the Alaska Department of Environmental Conservation.

The state commissioners for Environmental Conservation, Fish and Game and Natural Resources as well as agency staff worked on a new version of the rule this fall that would be consistent with existing state policy on protecting anadromous fish streams, Kent said.

"A key part of the new approach is to bring (the Department of Natural Resources) or (Department of Fish and Game) into any decision to allow mixing zones in spawning areas," Kent said.

The state proposes to authorize mixing zones in spawning areas if permit applicants meet certain criteria. Among the criteria: The timing of the discharge or types of pollutants must not affect spawning, incubation or rearing fish. Also, the applicant must demonstrate to the Fish and Game and Natural Resources departments that it can counter the effects of its discharges. Such measures could include creating new spawning habitat.

The new draft rule appears to answer a criticism from some environmentalists who had questioned why the state didn't just give waivers in cases where an exemption might be warranted.

A much-discussed example of such an exemption is the city sewer plant in Valdez, which built a ditch to discharge wastewater containing elevated levels of fecal coliform to the ocean. The ditch has since been colonized by salmon.

Kent said Monday current state regulations for mixing zones do not allow waivers.