environmental Strategist™, between the lines: What is a pollutant? In this case fresh drinking water. environmental Strategist (eS) define a “Pollutant” as a material, substance or product that gets introduced to an environment for other than its intended use or purpose. In other words, something that ends up where it does not belong, like fresh drinking water.
Water leak kills fish – Tuesday, February 12, 2013
A broken pipe sent thousands of gallons of drinking water cascading into San Mateo Creek over the weekend, killing scores, possibly thousands, of fish from chlorine poisoning.
The dead fish began floating to the surface Saturday when a thousand gallons a minute of chlorinated water flowed down a forested hillside into the creek about a half-mile below Crystal Springs Reservoir, according to utility officials and residents. Utility officials located the break in a 60-inch-diameter pipe next to a concrete bridge. It took them eight hours to cut off the flow along a 4-mile section of pipeline, but water was still leaking out Monday at a rate of 200 gallons a minute, officials said.
The exact death toll has not yet been determined. Rare steelhead trout, which have been listed as threatened along the Central Coast under the Endangered Species Act since 1997, were believed to have been killed.
The San Francisco Public Utilities Commission oversees the sprawling network that supplies drinking water to 2.5 million people in San Francisco, San Mateo, Santa Clara and Alameda counties.
Aging pipes, “We don’t know if it was corrosion or a seal or what,” said Steven Ritchie, the assistant general manager for water at the utilities commission. “There are joints in pipes. Sometimes they shift. We don’t know exactly why it broke, but it was undoubtedly related to its old age.”
“One of the challenges with drinking water is that the things we need to add to it to make it safe can be toxic out in the environment,” Ritchie said. “The chlorine is what makes it safe for us to drink, but it doesn’t do very well in a stream. It’s basically bleach and it kills fish.
Besides trout, sculpin, stickleback and suckerfish were killed. Ducks, great blue herons and other wildlife were feeding on the dead fish, which range in size from 6 inches to a foot. “I don’t know if it killed all the species,” Rogers said, “but the creek looks sterile. It could take years for it to recover.”
“As far as I’m concerned, any fish that we kill is a problem,” Ritchie said. “We pride ourselves on taking care of the environment, so this is
really of great concern to us. Our job now is to make sure it doesn’t happen again.”
Peter Fimrite and Kevin Fagan are San Francisco Chronicle staff writers.