An investigation into how a large water main that burst and flooded River Road in Montgomery County last year was allowed to be installed improperly has found that inspection records for the pipe might have been thrown away inadvertently, leaving the Washington Suburban Sanitary Commission unable to determine whether other pipes could have similar problems, WSSC officials said Thursday.
Officials said three months of searching have failed to turn up daily inspection reports that would have revealed what the utility's inspectors witnessed as the 66-inch concrete pipe was laid in the ground in 1965, or at least what they recorded. A Florida-based consultant found in May that the pipe was installed directly against jagged rock and lacked the required bedding of gravel designed to cushion it against cracks and corrosion.
After the report's release, WSSC officials said they would investigate how many other pipe installations the same contractor and inspectors were involved in to determine how widespread the rock problem could be and whether inspections on any of those pipes should be made a higher priority. However, the utility's interim general manager and chief engineer said Thursday that they have deemed such a search impractical.
Instead, they said, they can better determine which pipes are weakening by stepping up inspections of the larger concrete mains to find those suffering corrosion, regardless of the cause.
"To me the message is these inspections are crucial," said Teresa D. Daniell, the WSSC's interim general manager.
Firefighters and police, using boats and a helicopter, had to rescue a dozen motorists Dec. 23 after they were stranded in a torrent of frigid, muddy water that cascaded down River Road in Bethesda when the pipe burst. The dramatic rescues, shown on television around the world, became a symbol of the potential danger of the nation's decaying underground infrastructure.
The River Road pipe's inspection reports could have been thrown away in March or April, when a storage room at the utility's Laurel headquarters, which contained microfilms of older documents, was cleaned out to make way for computer equipment, said WSSC spokesman Jim Neustadt. He noted that the microfilms were thrown away one or two months before the search began for the River Road records.
"We don't know for sure that those records were in there," Neustadt said. He said WSSC policy requires such records to be kept two years, but they are often kept longer. However, the inspection record could also have been discarded years ago.
