OAKLAND, Calif. (KTVU and wires) -- A non-standard valve turned the wrong way caused as much as 106 cubic yards of cement -- about 12 cement trucks worth -- to be pumped into an Oakland creek Wednesday morning, local and state officials said Thursday.
Glen Echo Creek has been left a gray, sludgy mess along Clarewood Drive to Broadway Terrace. Crews dammed storm drains about a half-mile downstream and redirected the water into a sewer for treatment, but some of the cement got through and did further damage to the creek bed in the nearby Claremont Country Club.
"There's a half-mile of creek that is virtually dead," state Department of Fish and Wildlife spokesman Andrew Hughan said.
The mix is not considered toxic to humans, but at least one bird has died and another was sickened by the spill.
"The great thing about watersheds is they regenerate themselves very quickly," Hughan said, adding that the impact was further reduced by the drought. The creek was flowing much more slowly than it normally would at this time of year.
The accident happened while the East Bay Municipal Utility District was working on replacing a 2-mile-long, 1930s-era pipeline that supplied water to 13,000 homes in the Oakland hills, district spokeswoman Abby Figueroa said.
The new pipeline has already been built and is in use. Before abandoning the existing, degraded pipe, the district planned to fill it with a lightweight cement to solidify it and prevent any structural issues in the future, particularly since the pipe runs underneath the nearby Lake Temescal dam, Figueroa said.
But despite an inspector reporting the more than a dozen valves along the 24-inch-wide pipe were closed, when a subcontractor began pouring the cement, it flowed from an open valve into the creek. The valve turned in an opposite direction than most of the district's 70,000 valves, so while the inspector thought it was closed, it was in fact wide open, Figueroa said.
A neighbor in the Clarewood Townhouses noticed the cement flowing into the creek and reported it at about 11 a.m., Figueroa said. The utility district responded, halted the pumping immediately, located the open valve and closed it off by about noon.
As much as 106 cubic yards of the cement might have gotten into the creek before it was shut off. District officials had estimated this morning that up to 170 cubic yards could have flowed into the creek, but revised the estimate downward after further investigation.
The substance -- a lightweight cement with a foaming agent called "cellular cement" that dries into a spongy material -- turned the creek into a light gray goop that crews today are scooping, shoveling and vacuuming from the creek bed. The cleanup is expected to last until Monday, Figueroa said.
The agency immediately notified state regulatory agencies, including the Department of Fish and Wildlife and the state Water Resources Control Board, who are evaluating the extent of the damage. Biologists have taken samples at various points downstream from the spill but results of those tests have not been determined yet.