RALEIGH – Public utility officials have solved the mystery behind a purported "sewer creature" seen in an online video taken under Cameron Village in Raleigh.
Local bloggers at New Raleigh picked up on the YouTube video after it was posted on the Gawker science fiction blog io9.com. The video shows a sewer camera inspecting a pipe under Cameron Village on April 27. The camera stops to focus on several pulsing sacs clinging to the crevices in the pipe.
Ed Buchan, environmental coordinator at the Raleigh Public Utilities Department, said staff biologists have confirmed that the "creature" is actually a colony of tubifex worms. The colonies attach themselves to roots that gradually work themselves into weak points in the pipes.
"They seem to respond to the light from the camera," Buchan said. "That light is pretty hot."
The worms naturally occur in sewage and pond sediment and are actually sold both live and dried as fish food in pet stores.
He said other staff members in the department have seen it before, although sightings aren't particularly common.
"I've seen a lot of sewer TV before and I've never seen them," he said. "We were surprised. We didn't know immediately what it was."
Buchan said the video appears to be legitimate, apparently taken when the owner of the sewer lines, York Properties, contracted a private company to inspect the pipes.
"This to my knowledge was not a motivating factor," Buchan said. "It was basically a check-up on the whole system."
A call to York Properties was not immediately returned.
Although the sewer system is private, it discharges into the public system. Buchan said the colonies don't present any problems with water quality.
He said it would be up to York Properties to decide whether they need to clear the pipes, since the formations, which are smaller than a tennis ball, don't typically block water flow.
"You want to try to keep the pipe as clear as possible regardless of what's in there," Buchan said. "On the other hand, it doesn't seem to causing any blockage."
As for the origins of the video, Buchan said a few staff members did see it about a month ago.
"We can't figure out who sent us this," he said. "I'm looking at this e-mail trail and I can't figure out who this is – doesn't work for the City of Raleigh."
But he said the device used to record the video is a standard piece of equipment for maintenance crews and companies.
"A lot of them are basically little robots. They have little tracks on them and they're cylindrical in shape to fit in the pipe," he said. "You just send it down there, unspool power and cable line and it drives in there pretty far. They're really neat little tools – expensive tools."
Even though the worm colonies are documented, Buchan said it's not very often that something catches him by surprise.
"Every now and then, you see something like that. Generally, the only things you see in sewer lines are roots, grease, maybe a rat or some bugs," he said. "Thankfully I don't have to mess to too much with sewers anymore."
But N.C. State University biology professor Tom Kwak said it may not be a group of worms.
"I think it's a colony of bryozoans," Kwak said. "They are small animals like a hydra that live together in colonies, and they stick out tentacles to feed. And when they're disturbed, they withdraw into small tubes that they built."
Kwak said the bryozoans aren't dirty and don't carry diseases, and they don't bite or sting.
"There's really no reason to clear them out unless they become an issue of clogging the sewer pipe," he said.