Contractor Incorrectly Installed Water Main That Burst on Bethesda's River Road
Thursday, May 21, 2009
A large water main that broke in December, sending a torrent of water down River Road in Bethesda that threatened motorists, ruptured because it was incorrectly installed directly against jagged rock 44 years ago, according to a consultant's analysis released yesterday.
A contractor did not lay the 66-inch-diameter concrete pipe in the required bed of gravel, which is used to cushion pipes to prevent cracks and corrosion, the report found. A four-foot tear was found in the part of the pipe that had been laid against the rock, according to a report by Lewis Engineering & Consulting of Gainesville, Fla.
Washington Suburban Sanitary Commission officials said the findings raise larger concerns for their 5,500-mile system of water pipes. The utility is pulling 1965 records for that pipe segment to determine what, if anything, the utility's inspector noted about the installation.
"This is just the first part of our investigation because it raises all sorts of questions," said Teresa D. Daniell, the WSSC's interim general manager. "What other projects did this contractor do, and where are they?"
Daniell said pipes installed by the contractor, particularly in rocky areas, probably would be made a higher priority for inspections. Much of Montgomery County has extremely rocky soil, while Prince George's County has less, she said. The utility provides water and sewer services to 1.8 million people in both counties.
WSSC's aging pipes have been breaking in growing numbers over the past 20 years, and the River Road flooding revealed how quickly the larger breaks can become life-threatening. Television viewers worldwide watched Dec. 23 as firefighters in wet suits and helicopters rescued a dozen motorists from vehicles stranded in the cascade of frigid, muddy water.
Montgomery County Council member Roger Berliner (D-Potomac-Bethesda), whose district includes the River Road area, said the report's findings underscore the need to increase inspections. The council committee that oversees the WSSC plans to question utility leaders at a briefing next month, he said.
"The broader question is if these people did such shabby work here in order to presumably save a few dollars, there could very well be other places where this is true," he said.
WSSC officials have been unable to determine whether the contractor, identified on project drawings only as "Tripp," is still in business, spokesman John White said. A Washington Post article on Oct. 30, 1965, shows that George Tripp Inc. was awarded a $587,166 contract to install a section of 66-inch water pipe along a nearby part of River Road.
Reached at home yesterday in Pennsylvania, George Tripp, 88, said that his company worked for WSSC but that he could not recall whether it installed the River Road pipe. "I don't think you'd install it against rock," Tripp said. On his company's jobs, he said, "there was an inspector there the whole time, watching the pipe be installed." Tripp said he sold his company 15 years ago.
Gary J. Gumm, the WSSC's chief engineer, said he thinks this is the first time the utility has found this type of incorrect installation. Contractors are supposed to remove all large rocks before laying pipes in gravel or other bedding, he said. A four-inch layer was required when the River Road pipe was installed, he said. Photos in the report show jagged boulders adjacent to a large gash in the pipe.
WSSC officials have said they are most concerned about larger, concrete pipes because they can explode without warning under high water pressure and cause widespread damage. WSSC leaders say such pipes should be scrutinized every five years but conducted virtually no inspections from 2001 to 2006, when the utility received no rate increase in some years and small ones in others. Some pipes have been inspected just once or twice in the past three decades, according to the utility.
The River Road pipe was last inspected in 1998 with less sophisticated equipment than the WSSC has now, Gumm said. The amount of corrosion was deemed a 2 on a 10-point scale and was not considered significant enough to replace that section of pipe. The main had no manufacturing flaws, according to the report.
A WSSC lawyer has determined that any warranty on the pipe's installation has expired, said White, the spokesman. The inspector's name should be on records that WSSC officials hope to retrieve from storage soon, Gumm said.
The 7.3-mile River Road pipe is one of two major lines that carry water from the Potomac River filtration plant to the rest of the system. The pipe, which ends near the Church of Jesus Christ of Latter-day Saints' Washington D.C. Temple, is scheduled for inspection this fall or next spring, Gumm said.
Staff researcher Meg Smith contributed to this report.