Committee Hears City Operates 108 Miles of Water Pipelines With High Risk of Failure

The City’s Municipal Services Committee on Tuesday heard Pasadena Water and Power’s plans to replace 274 miles of the city’s ageing water supply pipelines over the next 25 years at a cost of $289 million.

PWP recommends the replacement of 108 miles of pipeline which have been assessed to have a high risk of failure, over a period of 10 years, at an estimated cost of $114 million, Vargas said.

In the next 11 to 25 years, the department recommends the replacement of 166 miles of pipeline which would cost $175 million.

According to Adolfo Vargas, capital project manager for the water division, approximately 50 percent of the pipes in use today in the City’s drinking water distribution system were installed prior to 1950.

The City’s drinking water distribution system consists of approximately 510 miles of pipeline that range from 2 to 42 inches in diameter.

Specifically, he said 34 percent of the system or 174 miles of pipeline are already over 80 years old, which is generally the life expectancy of water mains.

About 28 percent or 143 miles of pipeline are 60 to 80 years old. Only 38 percent or about 193 miles of the pipeline were installed since 1960.

Aside from the risk of failure, Vargas said other factors that also weigh into prioritization are water quality complaints, future development, new sources of supply and public works projects.

According to Vargas, the materials that will be used for the new pipelines will not be the same with what were installed years ago. For the pipes, ductile iron will be used instead of cast iron, he said.

“We believe that the durability could take us past a hundred years,” Vargas added.

Vargas said the life of old pipelines which are not assessed to be at high risk of failure can be extended with proper maintenance and timely rehabilitation.

According to Vargas, the city has installed 95 miles of pipelines since 2002.

He said the water mains upgrade projects which are already in the pipeline include Colorado Boulevard from Meredith Street to Altadena Drive, Altadena Drive from Woodlyn Road to Paloma Street, San Gabriel Boulevard from Walnut Street to Millicent Way and Arroyo Parkway from Cordova Street to Glenarm Street, among others.