DWP Vows to Correct Bouquet Water’s Smell : Reservoirs: An official, responding to complaints, says the addition of ozone will eliminate the naturally occurring odor, which he says is harmless.

The Los Angeles Department of Water and Power announced Wednesday that it will begin adding more ozone to San Fernando Valley water supplies to eliminate an odor that had prompted several dozen complaints.

The odor, which was described as “earthy or musty,” is harmless and occurs naturally in the department’s Bouquet Canyon Reservoir when hot days are followed by cool nights, said Robert Y. Yoshimura, assistant director of water quality for the DWP.

“When temperatures change and nutrients in the water are decreased, the algae populations die, releasing an odor that is harmless,” Yoshimura said.

“These compounds don’t cause any sickness or anything; they just smell bad,” he said. “The water from Bouquet Reservoir is really strong. It smells like wet dirt or mud. . . . Some people said it smells like old sewage. Others think it smells like chemicals.”

The cause of the smell is either Methyl-Iso-Borneol or Geosmin--both of which have been found in the Bouquet Reservoir in the past, he said.

To eliminate the odor, the DWP on Tuesday doubled the amount of ozone added to the water supply, Yoshimura said.

The problem was first noticed Sunday night when several people called DWP officials complaining of a musty, fetid smell in their water.

“It started in the Northwest Valley and migrated to the Woodland Hills, Canoga Park area,” said DWP spokeswoman Debra Sass.

DWP officials investigated the smell and found that Bouquet Reservoir was the source.

“It has an unfortunate name,” Yoshimura said.

The smell is more pronounced in warm and hot water.

“The people who have complained the most are those who have smelled it while taking a shower,” he said.

Several people who called the department were afraid that some dangerous chemical had been added to the water, Yoshimura said.

One confused man called Yoshimura on Wednesday morning and wanted to know if the smell was his imagination or a real problem.

“He was upset . . . He thought it was a chemical smell. He was relieved we knew what,” Yoshimura said. “He thought he was the only one smelling it. I told him: ‘No, it’s not your imagination. It’s the whole Valley.’ ”