Correction: Due to an error in a report by the Washington Suburban Sanitary Commission, an earlier version of this article incorrectly stated that such pipes can explode with the force of up to 200 tons of dynamite. The correct measure is up to 200 pounds of dynamite, according to the WSSC.

Utility officials for Montgomery and Prince George’s counties established a special committee nine months ago to consider whether new buildings need a bigger safety buffer from potentially explosive water mains, but the group has yet to meet.

The Washington Suburban Sanitary Commission proposed an expanded building setback in May, likening it to additional safeguards needed in earthquake zones. Future homes, schools and offices, WSSC officials said, needed better protection from the utility’s aging, highly pressurized pipes that can explode with the force of 200 pounds of dynamite, hurl rocks 90 feet and leave behind 50-foot craters.

Little has happened since. The WSSC panel of utility experts and local public officials charged in June with analyzing the issue has an incomplete roster and no meetings scheduled.

The inaction has left some local officials questioning whether the WSSC suffers from bureaucratic lethargy or has quietly backed off the idea since officials in both counties balked. Expanding the building setback to 80 feet, local officials say, would severely hinder both counties’ plans to attract and focus development in dense, urban areas — many well within the proposed buffer zone. The current setback is 25 to 33 feet, depending on the size of the pipe.

“It’s the classic issue of creating a committee and doing a study as a delay action,” said Montgomery County Council member Nancy Floreen (D-At Large). “It’s a standard approach to not saying ‘no’ but not doing anything.”

What happens when water mains burst

WSSC officials say they’re not trying to stall. They say they’ve been waiting on outside groups, such as citizens groups, to appoint representatives to the recently expanded panel.

“This is not something that should be pushed aside,” said Jerry N. Johnson, WSSC’s general manager. “People need to understand there could very well be some risk.”

The delay has highlighted the fact that the panel, if it ever meets, will face a politically sensitive calculation: how to weigh the potential public safety risks of the area’s aging underground infrastructure — some of the largest concrete mains date back to World War II — against the potential benefits of spurring new development.

“It’s going to be an enormous task to deal with this issue,” said Howard Stone, administrative specialist for the Prince George’s County Council.

Another thorny question: How does a utility argue that it needs to better protect people in the future while also ensuring the safety of those who already live, work and attend school within the 80-foot zone?

WSSC officials have declined to release maps showing the largest pipes’ locations, citing security concerns. However, the utility has said 1,768 buildings in both counties are already within the 80-foot zone. Under the WSSC’s proposal, any new buildings within 80 feet would have to be designed to withstand the blast of a major break.

The larger transmission mains are so massive — the WSSC’s largest eight-foot pipes could hold a minivan — that they are physically impossible and too costly to move, experts say.

Though water utilities across the country are struggling with aging pipes, there is no industry standard for building setback distances, according to the American Water Works Association. They are typically set based on the health of a system’s pipes, local soil conditions and other factors, a spokesman said.

DC Water has no building setback for most mains in public rights of way, such as beneath roads, said spokeswoman Pamela Mooring. Particularly large pipes that cross private property require easements of up to 35 feet on both sides. Buildings within those easements must be designed so they don’t put a load on the pipe, but they are not required to be fortified against a break.

Fairfax Water, which serves Northern Virginia, has a 20-foot setback for new buildings, said spokeswoman Jeanne Bailey.

The Maryland suburbs have had five major breaks since 1996. Those included a 2008 rupture in Bethesda that required motorists to be rescued from a torrent of water via boats and helicopter, and a 2011 break in Capitol Heights that shut down the Capital Beltway and blew out walls in an office park.

Public officials in Montgomery and Prince George’s say safety would trump economic development. However, they say, the WSSC has yet to show how likely such breaks are to occur and how much additional protection a larger setback would provide. Several public officials said they would then weigh those findings against the additional costs that property owners would incur and the economic losses from development that wouldn’t happen.

“WSSC has raised the flag, so let’s talk out what that [distance] should be,” said Carla Reid, deputy chief administrative officer for Prince George’s.

Johnson said the WSSC hired a facilitator in September to help the group charged with analyzing the setback proposal.

However, he said, momentum slowed in October after the councils and executives from both counties asked the WSSC to expand the group to include city officials, private developers and others.

WSSC has since put the facilitator’s $80,000 contract on hold and is waiting for some of the additional appointees, Johnson said.

Several public officials noted that the WSSC, funded by a 50 percent increase in customers’ bills during the past six years, has spent $21.2 million since 2007 to install and monitor acoustic equipment inside the largest pipes.

The equipment is designed to detect the “ping” sounds of a pipe’s reinforcing steel wire beginning to snap, giving the utility time to shut it down before a rupture.

Such equipment led the WSSC to shut off an eight-foot pipe in Montgomery in 2010. Crews later found a badly deteriorated section beneath a residential area off Tuckerman Lane, 50 feet from a house, according to a WSSC report.

“WSSC has told us that our communities are safe,” said Montgomery Council member Roger Berliner (D-Potomac-Bethesda). “We’ve told our communities they’re safe, and we believe it to be true. The burden is on WSSC to show more is needed.”

WSSC officials said 163 miles of pipe three feet and larger would be covered by the proposed setback. Half of that pipe — almost 80 miles — will have the acoustic equipment by the end of June, officials said.

A bigger setback is necessary even with stepped-up inspections and new technology, Johnson said, because “nothing made by man is fail-safe.”

Travis Wagner, a vice president of Pure Technologies, the Columbia company that is installing the acoustic system for the WSSC, said the company has never had a pipe with its equipment burst before a utility detected the warning sounds and intervened.

The company’s equipment has been installed in about 560 miles of pipe worldwide since 2005 and has detected “well over a dozen” impending breaks, Wagner said.