A contractor using a remote-operated underwater camera was able to locate and video the community’s damaged wastewater outfall line on Sept. 11, with the borough hoping to put together a game plan this week to repair the damaged pipe.
The six- or seven-foot section of damaged 12-inch-diameter plastic pipe is in 77 feet of water, about 1,500 feet from shore, said Tom Wetor, the borough’s Public Works director.
Before a boat hooked the pipe when it was pulling up its anchor on Aug. 30, the outfall pipe carried flow from the wastewater treatment plant about 1,800 feet, discharging it into water 120-feet deep, providing enough dilution with the current to meet federal water quality standards.
The contractor, who was in Wrangell last week for other work, was able to pilot its underwater equipment to inspect the entire length of the pipe, Wetor said Sept. 13. “We can see the damage and the kink” where the anchor bent and closed off the pipe. “We were able to get some pretty clear images of it.”
Immediately after discovering Aug. 30 that the damaged pipe was blocking the outfall line from doing its job, causing a backup at the plant, the borough cut into the pipe on the beach near City Park to allow the flow to spill into the tidal area, where it is swept out twice a day.
The effluent coming out of the line has been treated at the plant — where all of the solids are removed — but as a safety precaution, the borough has closed the park beach to the public.
Wetor said the borough would work with its engineering contractor and the Environmental Protection Agency to put together a repair plan to resume deep-water disposal of the treatment plant’s flow.
He is hopeful the borough can cut out the damaged section of pipe and reattach the two pieces to restore service far enough away from shore and in deep enough water to meet EPA standards for dilution.
He was impressed with the capabilities of the underwater equipment, which he described as so small that it could fit in a suitcase. The borough chartered a boat from Muddy Water Adventures to take out the contractor for the inspection work.
“The technology definitely is very helpful,” Wetor said.
Fortunately for the borough, the contractor had been scheduled for a work trip to Wrangell last week to inspect and clean the holding tanks at the wastewater treatment plant. The timing allowed for a quicker response time to inspect the outfall line.
While at the treatment plant, the crew put to work their remote-operated vehicle — with a cleaning attachment — to scrub down the tank walls, which hadn’t been done in 18 years on the older tank, Wetor said, and had never been done on the newer tank that is 15 years old.
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