Additional Water Main Repair Ordered

Calleguas Municipal Water District engineers on Tuesday ordered construction of a second section of steel-jacketed 5 1/2-foot-diameter concrete pipe after learning that Simi Valley’s water main suffered worse damage in a weekend blowout than originally thought.

“We ordered an extra 20-foot-long section because when we removed the first section, it looked like [an abutting section] had sustained some damage right on the edge,” said Donald Kendall, the district’s general manager.

The more heavily damaged pipe section--designed to handle pressure of 120 pounds per square inch--exploded on Saturday when a surge of water hit a closed valve at an estimated pressure of 500 pounds per square inch, Kendall said. The rupture flooded streets with 8 million gallons of water, leaving a sinkhole in Madera Road and forcing traffic to be detoured around the site during repairs, which could take up to two weeks.

The “water hammer,” as engineers call such a surge, also knocked a mortar sheath off an adjacent section of pipe, which led engineers to order a replacement, he said.

“We could put something externally over that, like a patch, but prudence will tell you to fix [the whole pipe],” Kendall said.

Work crews in the Metropolitan Water District’s La Verne welding shop are hurrying to manufacture the pipe sections for the repair job, which Kendall said could cost $100,000.

“We’ll roll and weld three-eighths-inch steel plate into two lengths of pipe with an inside diameter of 66 inches,” said Jim McKay, an assistant operations and maintenance manager for the Metropolitan Water District, which delivers water to Calleguas. He said the agency expected to ship the pipes today.