O.C. Crews Cleaning Up Spilled Caustic Fluid : Contamination: A storm drain and Santa Ana River channel were dammed to contain a liquid discharged at a water district facility in Fountain Valley.

Crews scrambled Wednesday to clean up thousands of gallons of a highly caustic solution that were inadvertently discharged into a storm drain at an Orange County Water District facility and washed into the Santa Ana River channel.

Water district personnel hastily dammed the storm drain and the river channel after a passerby spotted green fluid running along the sidewalk outside the facility on Ellis Street about 9 a.m., said William Mills, general manager of the district facility.

The discharge of about 5,000 gallons of sodium hydroxide and water containing green dye occurred after workers completed patching a 41,000-gallon tank. Unaware that the tank still held sodium hydroxide, workers drained the mixture spilled onto the sidewalk.

The pool of contaminated solution was believed to have been contained by hazardous materials crews who rushed into the river channel with shovels to build makeshift dams ahead of the advancing spill, Mills said.

About 30 officials from the county Environmental Management Agency, Fountain Valley Fire and Public Works departments, and the California Department of Fish and Game joined in the effort, Mills said.

There were no reports of injuries, and the spill did not pose a public threat, officials said.

Water district and Fire Department officials blamed workers from Hunter Corp., a Fountain Valley construction company, for the discharge.

“It is hard is to imagine that anyone would do any dumping, regardless of what they thought was in (the tank), without testing first,” Mills said. “It is like a loaded gun.”

Officials at Hunter Corp. declined comment.

Tests done near the source of the discharge showed the escaping fluid was caustic enough to burn skin on contact, said Tom Pimm, a hazardous-materials inspector for the Fountain Valley Fire Department.

After discovery of the discharge, cleanup crews followed the trail of the green solution down the gully, through the storm drain and into the river channel. They built a series of dams to catch the contaminated water, then diluted and neutralized it.

The crews brought in four pump trucks to drain the contaminated pool from the channel and then flush the storm drain.

The Hunter Corp. workers had patched a leak in the sodium hydroxide storage tank. The chemical is used as a neutralizing agent in the event of a chlorine leak, Mills said. Chlorine is commonly used in the water-treatment process.

After completing the repairs, workers pumped in green dye to check for leaks, after which they drained the tank through a hose and onto the sidewalk.

Water district officials said Hunter Corp. would probably not be cited for the discharge but would be asked to pay for the cleanup effort, the cost of which was not immediately determined.