Update Friday, 2:10 p.m.
Utility and wildlife officials say they've discovered as much as 200 more feet of Oakland's Glen Echo Creek impacted by a cement spill this week.
Crews had been clearing about 12 truckloads of what California Fish and Wildlife spokesman Andrew Hughan calls "light and fluffy" cellular cement. Hughan said they missed seeing the additional affected area.
"100 percent of our effort was focused on that immediate triage. And, yeah, looking back, we'll do better next time on surveying the entire site beginning to end, and that's what we're doing today."
Hughan said his teams are scouting the whole creek today, and he expects the cleanup to extend into next week.
The agency is investigating how a nonstandard valve was left open during a water pipeline replacement Wednesday by the East Bay Municipal Utility District.
The valve at the center of two investigations into a major cement spill in a creek in Oakland's Rockridge neighborhood was inspected nearly a week ago, a spokeswoman for the East Bay Municipal Utility District said.
The nonstandard valve, which closes in a counterclockwise direction, may have been opened accidentally or misidentified by an inspector, EBMUD spokeswoman Abbie Figueroa confirmed to KQED.
When a contractor working on an EBMUD water pipeline project was feeding cement into an older pipe that had apparently had the valve open on Wednesday morning, up to 106 cubic yards -- equivalent to 12 truckloads -- of the gooey substance spilled into Glen Echo Creek, killing off wildlife and prompting a major cleanup effort.
Ninety minutes after the sludge spilled out of the older pipe, crews were able to shut off the valve and stop the flow of cement into the creek, but not before it traveled a half-mile into the watershed.
Crews closed storm drains to divert the cement into the sewer system and away from Lake Merritt, but the spill has seriously impacted the creek's ecology.
"Anything living in that creek, all the bugs, all the plants, everything that was living in that creekbed in that half-mile is gone (or) killed, unfortunately," said Andrew Hughan, a spokesman for the California Department of Fish and Wildlife.
EBMUD has been taking water samples to determine if the spill's impact stretches farther. Late Thursday, Figueroa said cement had affected an area near the Claremont Country Club.
Cleanup Could Take Long
While Figueroa has said the cleanup should take several days, Hughan said it would last much longer.
"This is going to take several weeks, months or even into next year to get this out because we can't just go in with a digger," Hughan said. "This is a very environmentally sensitive area, so it's probably going to have be done with shovels and buckets one at a time."
Figueroa said the contractor involved in the project is also using vacuums to suck up the cement.
"After the cleanup is done, then the restoration begins," Figueroa said. "We will return this to as close to the way it was."
Hughan said re-establishing the area for wildlife will take a long time. "When the water starts flowing again and when the contractor gets this removed, the waterway will fix itself over the next couple of years," he said. "It's going to be a long process to make it right."
Figueroa said the main contractor on the project to replace 2 miles of aging pipe in the Oakland hills is Ranger Pipelines, a San Francisco-based utility-engineering firm.
Peter Cuddihy, the company's operations manager, responded to a request for comment by emailing a statement. "Ranger Pipelines has no comment on what happened as the cement spill that occurred is an internal EBMUD matter and we are assisting EBMUD in their cleanup efforts," he wrote.
The subcontractor, Figueroa said, is Cell-Crete Corp. That company describes itself as the largest installer of lightweight insulated concrete in the western United States.
"It was an unfortunate accident," said Patrick Barclay, Cell-Crete's vice president. "Cell-Crete is grateful to see the responsible party, EBMUD, accept responsibility for the accident and clear Cell-Crete's name from any wrongdoing."
EBMUD and the law enforcement division at Fish and Wildlife are investigating.