State proposes to keep 1-acre seafloor waste zones for offshore seafood processors

The Alaska Department of Environmental Conservation proposed Monday to keep letting stationary seafood processing vessels leave fish waste on the seafloor in patches of up to 1 acre per discharge site. The proposal is part of a draft reissue of the state's general permit for offshore seafood processors, which covers stationary processing vessels discharging between shore and 3 nautical miles out.

The 1-acre limit is not new. DEC issued the permit in 2011 and reissued it in 2018 with the same 1-acre patches. The 2018 version expired at the end of 2023, but it stays in force until a new one replaces it, according to DEC's draft fact sheet.

Inside these zones of deposit, seafood waste residues may exceed state water quality standards. The zones apply only where a stationary vessel discharges into water less than 120 feet deep. Under the state's zone-of-deposit regulation, standards must still be met at every point outside the zone.

The draft updates how DEC measures the 1-acre limit. Seafloor with continuous waste coverage of 95 to 100% and with more than 50% scattered coverage would both count toward it. Operators would also have to identify Beggiatoa bacterial mats and submit a map of the coverage they observe.

Stationary vessels within 1 nautical mile of shore may still discharge no more than 3.3 million pounds of seafood waste a year at each site.

The permit also covers inland waters discharge vessels, which release processing waste into bays, river mouths and enclosed harbors. For the first time, they would have to test the surrounding water once per permit term at each discharge site. DEC says the results will help show how large a mixing zone ammonia needs to fall to water quality standards.

The state's final permit for onshore processors in Kodiak, issued this year, does not authorize a zone of deposit.

Comments are due by 11:59 pm AKST Dec. 9 through the DEC public notice site. Anyone may request a public hearing.