LONG BEACH — A regional sewage treatment plant that recycles waste water for irrigation returned to service Wednesday after the detection of cyanide forced a 10-day shutdown.
When the deadly chemical was discovered at the Long Beach Water Reclamation Plant, officials had to divert 25 million gallons of effluent a day to another plant and spend thousands of dollars on cleanup. Although the chemical was a potential threat to workers, no one was injured, according to a spokesman for the County Sanitation Districts.
All Deny Blame
Officials suspect that one of about six industrial users of cyanide within the plant's service area--Long Beach, Signal Hill and Cerritos--may have accidentally dumped the chemical into the sewers. They add, however, that all of the companies have denied responsibility.
McDonnell Douglas Corp. had a 600-gallon cyanide spill in Building 5 at its Long Beach aircraft manufacturing facility on Jan. 15, corporation spokesman Don Hanson acknowledged. That was the first day that cyanide showed up in samples from the sewage plant.
But, Hanson said, "As far as we can tell, we kept it out of the sewers. It was contained in dikes around the tanks."
When cyanide was detected, effluent normally processed at the treatment plant--near the intersection of Willow Street and the San Gabriel River Freeway--was diverted to the larger Joint Water Pollution Control Plant in Carson. No sewage went untreated, including the waste water contaminated by cyanide, officials said.
The cyanide could have formed a deadly cloud and threatened workers at the plant if it had come in contact with acid, said Robert Wienke, enforcement project engineer for the districts.
In the plant's treatment process, raw sewage pours into huge tanks where it is mixed with a certain type of bacteria. The bacteria break down the sewage into non-potable water that is further treated so that it can be used to irrigate lawns at public parks, college campus and cemeteries.
The cyanide contamination, however, killed the bacteria and temporarily brought the treatment process to a halt.
"It basically put the plant into shock," Wienke said.
'Have to Get Bugs Happy'
To restart the process, bacteria-filled sludge was trucked from a sewage treatment plant in the City of Industry and used to recharge the population of microorganisms at the Long Beach plant.
"It's a biological process. You have to get the bugs happy again," explained one sanitation official.
Civil engineer Edward J. Fandi said the costs of the shutdown are still being calculated. They range from paying for the sludge trucks to paying for the extra manpower used to find and correct the plant deficiencies.
Wienke said he is trying to track down the company that spilled the cyanide, which is mainly used in the metal electroplating process.
"I guarantee no one will 'fess up," he said. "Potentially, they could lose their ability to (legally) discharge into the sewer . . . if we found the culprit and were convinced beyond a shadow of a doubt it was them."
Wienke said so many days have elapsed since the cyanide was discovered that the investigative trail "is getting kind of cold."
Times staff writer Myron Levin contributed to this article.