The water main explosion last month in Chevy Chase, Md., created a crater near Connecticut Avenue large enough to swallow a school bus. It also uncovered a possible flaw in how the Washington Suburban Sanitary Commission monitors miles of water pipes beneath the Maryland suburbs.
The utility says the huge break happens along a portion of the pipe that is not monitored by fiber optic cables. The WSSC says it was essentially at a steel joint connecting a 60-inch pipe to a 54-inch pipe.
Utility experts say no monitoring equipment was installed, because these types of joints were not considered vulnerable to ruptures. There could be as many as 800 such unmonitored joints in Montgomery and Prince George's counties.
In the past, the utility has proposed that any new construction be done 80 feet from its largest water mains to avoid the dangers of an exploding pipe. The current set backs are around 30 feet.