BETHESDA, MD — The Washington Suburban Sanitary Commission (WSSC) has said it will take another six weeks to determine the cause of the massive December 23 water-main break in this suburb northwest of Washington, DC, a break that forced helicopter rescues of motorists and has closed a busy traffic artery.

As carried by radio station WTOP, the Associated Press reported December 29 that a total of five sections of the 66” main will have to be replaced in the area of the break, where workers have found cracks and significant corrosion in the pipe.

River Road — the busy highway where a 4-foot wall of water from the break last week slammed against vehicles, washed them and heavy debris downstream and threatened several motorists — will remain closed until at least December 31 to complete road repairs, a December 26 WSSC press release said. The WSSC has been able to resume normal water service to most customers in the area.

“Pieces of the pipe will be analyzed as part of a forensic investigation of the rupture,” the release said. “While it is too early to determine a cause, there is considerable corrosion of the pipe where the break occurred.” The WSSC said it will keep area residents informed through the media and the utility’s Web site. At last report, about 1,800 feet of the pipe had been inspected by engineers.

A few motorists caught in the gushing water received minor injuries, and there were no deaths, but a number of motorists were trapped in their semi-submerged vehicles before firefighters and helicopter crews could rescue them.

The huge pipe is about 15 feet underground, and the spewing water created a 30-by-50-foot crater and washed away several large trees, the Washington Post reported December 27. According to the AP, the break gushed at a rate of about 150,000 gallons (568 cubic meters) per minute before water flow was cut off and diverted by the WSSC.

The WSSC describes itself as the nation’s eighth-largest water and wastewater utility. It serves more than 1.8 million customers in two suburban Maryland counties next to Washington: Prince George’s County and Montgomery County. The utility operates seven water and wastewater plants and has about 5,500 miles of drinking water supply lines and 5,300 miles of wastewater pipes.

To read the December 29 Associated Press report carried by WTOP radio, click here.

To read the December 27 Washington Post article, click here.

To read the full WSSC December 26 press release, click here.

To access the WSSC Web site home page, click here.

To read a December 24 Washington Post news article about the original main break, click here.

For related information, click here or here.