Kitty Felde |

NTSB hearing on San Bruno pipeline highlights cost of replacing old pipes

How much will it cost to replace the nation's aging pipes and valves?  Linda Daugherty of the federal Pipeline and Hazardous Materials Safety Administration told the National Transportation Safety Board that replacing just half the nation's valves alone could cost 600 milllion dollars. 

Tomorrow, the NTSB looks at new technologies that are able to detect leaks or cracks in underground pipes.