It sounds like something straight out of an action-adventure movie: an intense, hours-long struggle to close a stubborn valve succeeds at the last minute, saving thousands from impending disaster.

一种lthough the real-life threat-在失败的边缘的高压水主要-may not have the panache of say, an alien invasion or nuclear meltdown, the华盛顿郊区卫生委员会（WSSC）, in suburban Washington, DC, will gladly take the alls-well-that-ends-well outcome over its original plan to implementa multi-day service outage affecting than 100,000 customersduring the hottest stretch of weather the area has seen so far this year.

这一戏剧性事件发生reinf 54-inch直径orced concrete high-pressure transmission line that delivers 10-15 million gallons of water daily to a large portion of Prince George’s County, Md., including residences, Andrews Air Force Base, and businesses such as the 300-acre National Harbor mixed-use complex adjacent to the Potomac River.

Installed in 1966 near the Capital Beltway, the pipe is part of WSSC’s350-mile network of high-pressure mains that has experienced multiple failuresin recent years. The most dramatic occurred in 2008, when asudden burst of a 66-in diameter main淹没了主要的道路，通过蒙哥马利县，MD的半乡。，需要直升机救援几个被困驾驶者。一种2011年失败just north of the current problem pipeline left more than 400,000 users without water for the better part of a week.

WSSC blames the failures on pipes manufactured using the once-acceptable practice of tightly-wrapped steel wire for reinforcement. The companies that supplied the pipe in the 1960s and 70s have since gone out of business. The agency notes says that although less than 2% of the concrete pipes are affected, the estimated total repair cost is just under $3 billion.

一种fter a装有故障检测传感器的60英寸管道在今年早些时候出乎意料地爆炸，WSSC决定在乔治郡管道的声学试验表明上周37个钢筋的钢筋在五天期间突破了37股。

“The pipe would likely have failed in the form of an explosion,” WSSC CEO and GM Jerry Johnson told reporters. “It would have been a public service disaster.”

一种lthough a nearby valve could divert water to a smaller main, requiring only a smaller section of the transmission line to be shut down, years of corrosion due to exposure to acidic soil had frozen the gears.

来自当地维修店的估计远远超过WSSC可以等待，留下更广泛的关机作为唯一的实用选项。快速跟踪的公众意识活动敦促客户准备持续五天的中断，在此期间，日间热量指数预计将定期前100名º。

Meanwhile, WSSC employees Brad Destelhorst and Tom Ecker volunteered to attempt one last-ditch repair of the valve. Starting Saturday, July 13, Destelhorst and Ecker took turns standing in a partially flooded, phone booth-sized vault using a hand grinder, chisels, scrapers, and a lot of elbow grease to reform the valve’s gears.

By late Tuesday, July 16, they had managed关闭阀门, allowing water to be diverted to other sections of WSSC’s water supply network. Once the bypass system’s ability to meet demand was confirmed, the agency cancelled the outage alert, although customers were asked to conserve water use until the transmission line repairs are completed this weekend.

一种visibly relieved Johnson praised the employees for persevering despite the constraints and doubts.

“这是之前从未完成过的事情，”他告诉记者。“工人远远超出了责任。”