MWD Finds New Chemical Spill in Yorba Linda Creek

On the same day last week when criminal charges were filed against the Metropolitan Water District of Southern California for a toxic spill in a Yorba Linda creek, a second spill fouled the same creek.

“It couldn’t have been more horrible timing,” MWD spokesman Jay Malinowski said Tuesday.

The Feb. 6 spill involved a nontoxic substance, but state water quality officials say they are investigating to determine if the water district, the biggest in Southern California, violated its discharge permit.

The chemical that spilled from the water treatment plant in Yorba Linda was a substance known as alum, or aluminum oxide, and is not considered toxic in low concentrations, said Kurt Berchtold, a supervising engineer for the state Regional Water Quality Control Board in Riverside.

“But it’s not something we like to see routinely discharged,” Berchtold said.

Last week, the Orange County district attorney’s office filed felony charges against the district and misdemeanor charges against four top MWD officials for the Oct. 26 spill of 466 gallons of caustic soda into Telegraph Canyon Creek.

The district faces a possible $1-million fine, and each of its officers faces a $75,000 fine and three years’ imprisonment on charges of negligence and knowingly disregarding the law. MWD has denied any criminal wrongdoing.

In the Feb. 6 spill, an estimated 10 gallons of alum sludge spilled into the creek after workers poured the sludge into a holding pond for use in the water treatment process, said Bob Gomperz, another MWD spokesman. The alum foamed up out of the holding pond and into the creek because the pond was dry for the first time in recent memory.

When water is in the pond, Gomperz explained, the alum reacts to help coagulate smaller suspended particles in the water into larger ones that can be more easily skimmed off. But since there was no water, Gomperz said, the alum turned into white-gray foam in the pond and a strong wind at the time blew it over the side.

The spill was not discovered until the next day, Gomperz said, when workers discovered the foam coating a 200-foot stretch of the creek, which leads down to the Chino Hills State Park.

Gomperz said that while it was not toxic, the alum is not supposed to be discharged into the creek. A state official said the MWD is permitted only to discharge 6,000 gallons of treated water per day into the creek.

“Only from an aesthetic point of view are we in possible violation of our permit,” Gomperz said, adding that the foam was quickly mopped up the day it was found and that the district promptly notified state water quality officials.

Deputy Dist. Atty. Jan Nolan said her office is investigating the latest spill.

The October spill occurred, MWD officials said, when a pressure relief valve malfunctioned and the caustic soda backed up into an underground drain line that discharges into the creek. The spill was not detected until two days later.

Nolan said her office has documents showing that the MWD had known since at least 1984 that caustic soda--used at the plant to reduce the water acidity level--would overflow into the creek if there was a malfunction of a pressure relief valve. The soda, which consists of sodium hydroxide, burns the skin on contact.