KNTV NBC Bay Area News At 6 January 4, 2012
looking into what caused the rupture last night. but some of their pipes are 100 years old. >> i believe the figure is something for a mile of pipe replacement is -- $5 million. we have 4,200 miles of pipe. if we had to match it. we would wave a wand and 1,500 miles would be retired. >> reporter: instead it works to replace at least 6 to 8 miles of pipeline per year. a civil engineer and professor at uc berkeley compared the bay area infrastructure to an aging body. as a person gets older, bones break more easily. scrapes can cause major damage. he says it is the same with old pipes....