Report: Cause of Connecticut Ave. Water Main Break Still Unknown

Washington Suburban Sanitary Commission engineers still do not know what caused the massive water main break on March 18 at the intersection of Connecticut Avenue and Chevy Chase Lake Drive, but they say that the fiber optic monitoring system installed in the pipes in 2010 did not fail, Bethesda Now reported.

The monitoring system detects only the sounds of snapping steel wires in the concrete pipes, but as the steel wires did not snap before the break, the monitoring system could not detect the impending break, WSSC chief engineer Gary Gumm told the Montgomery County Council’s Transportation and Environment Committee on Monday morning, Bethesda Now reported.

But, "[that] is a distinction however that has very little comfort to our community because the purpose of the [acoustic fiber optic monitoring] system is to give us warning," Council Member Roger Berliner (D-Bethesda and Potomac) said at the committee briefing on Monday, Bethesda Now added. 

The design of the pipe segment that broke "affects 700 to 800 other pieces of pipe throughout Montgomery and Prince George’s counties," Gumm said, The Washington Post reported.

A full forensic report on what caused the water main to break is expected in June, Bethesda Now added.

Read more about Monday's briefing on Bethesda Now's website.

The Washington Post reported that a Chevy Chase resident noticed "water squirting up from an opening in a circular metal plate embedded in Chevy Chase Lake Drive" about seven hours before the water main break. An inspector found what he thought was a leak in the valve, and determined that it could wait until the morning.

The Post also reported that the broken pipe was made by Interpace, a defunct company in New Jersey that "the WSSC and other utilities successfully sued for flaws that left the pipes more prone to breaking." Most of WSSC's 350 miles of concrete water mains were made by Interpace, Jim Neustadt, a WSSC spokesman, told The Post.

While the break did result in a massive geyser and crater, and 60 million gallons of water were lost—necessitating mandatory water restrictions for five days in two counties—no one was hurt by the water main break.

Editor's note: This post has been updated.