Borough moves toward plan for repair of wastewater outfall pipeline

Though it was important to pinpoint the exact location and extent of damage to the community’s wastewater outfall pipeline into Zimovia Strait, officials also discovered that the 12-inch plastic pipe and the seabed around it have become home to hundreds of sea cucumbers.

“Over the years and years, wildlife has figured it out,” Tom Wetor, the borough’s Public Works director, said Sept. 26. Sea cucumbers, a bottom-dwelling invertebrate, proliferate around the nutrient-rich waters near the diffuser end of the outfall line, he said.

“I bet there are more than 600 around that line,” Wetor said after viewing an underwater video of the pipeline. “They’re right on top of that pipe.”

But it wasn’t the colony of sea cucumbers — a traditional subsistence food for Alaska Natives and a valuable commodity in some Asian markets — that damaged the pipe. It was a boat owner who pulled up anchor on Sept. 11, tugging on the outfall line.

“It’s clear in the video that there is an anchor attached to the pipeline,” Wetor said of the damaged pipe, which was bent and kinked when the boat owner started to pull on the anchor line, closing off the pipe and causing a backup at the borough’s wastewater treatment plant.

The borough temporarily solved the backup problem by cutting into the shallow-buried pipe on the beach at City Park, which has been closed to the public since the incident. The outfall spills onto the shore and washes out with the tide twice a day.

The borough sent the 45-minute video to its engineers and state and federal officials last week, and hopes the U.S. Environmental Protection Agency, which enforces the Clean Water Act, will allow Wrangell to cut out the damaged section of pipe and reconnect the rest of the line to restore flow to deep water.

“That’s definitely what we’re shooting for,” the Public Works director said.

Before the damage, the line extended out about 1,800 feet from shore, into water 120 feet deep, Wetor explained. If the EPA allows the borough to simply reconnect the undamaged sections, the pipe would reach about 1,700 to 1,750 feet, discharging into water at about the same 120-foot depth, he said.

The break is in water about 77 feet deep and would require professional divers for the repair job. “The video worked out great” in providing the images and information needed to assess the damage and present the case to regulators, he said.

Wrangell’s case to regulators will be that “the discharge point (of the outfall) is not appreciably different” from where it was before the accident, Wetor said.

In addition to shrimp, some sculpins and a couple of Dungeness crab, it was the number of sea cucumbers that stole the show in the underwater video.

Coincidentally, the Southeast Alaska commercial dive fishery for sea cucumbers will open Monday, Oct. 7, with the harvest guideline set at 1.76 million pounds, up slightly from last year’s 1.67 million pounds.

Only designated areas are open for the harvest, as regulated by the Alaska Department of Fish and Game based on biomass surveys of the population.

Last year, 150 divers fishing from 115 vessels across Southeast took 1.64 million pounds, receiving an average $5.22 per pound, according to department information.

The largest portion of the Southeast harvest guideline is allocated to Ketchikan-area districts, where E.C. Phillips is the primary buyer for sea cucumbers, according to Fish and Game.

Sea cucumbers may only be harvested by hand, according to state law. Divers pick the purplish, orange-knobbed filter-feeders off the seafloor, place the cucumbers in bags and send them to the surface where they are selected, eviscerated, boiled and processed within hours to prevent spoilage. They are salted and frozen before being exported to Asia as a food delicacyand for their supposed medicinal properties.

 

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