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After the second water crisis in two years, OWASA discusses emergency prevention

owasa-meeting
OWASA board members John Young, Jody Eimers and Bob Morgan discuss the water main break at the Nov. 8 meeting.

After a water main break two years ago and a water main pipe fracture on Monday, which resulted in 9.4 million gallons of water lost in Carrboro, the Orange Water and Sewer Authority Board convened Thursday night to disclose the agency’s emergency response actions as well to discuss preventative measures moving forward.

Three water tanks supplying Chapel Hill and Carrboro were completely depleted by 9 a.m., the result of a 16-inch main water pipe fracturing on Jones Ferry Rd. The cause of the fracture is still unknown, but OWASA officials found significant corrosion within the 77-year-old pipe.

The fracture occurred at 6 a.m., and OWASA engineers successfully isolated the leakage by 2 p.m. Todd Taylor, OWASA’s manager of operations, said initial failures to contain the leak resulted in an 8-hour gap between finding and stopping the water break.

Taylor said the initial response was to turn off system water valves, similar to the knob on household sinks or tubs, to stop water coming out of the system. 

After the action failed to work, he said his team issued a water conservation warning to Chapel Hill and Carrboro. Still, water consumption remained relatively high, just 25 percent lower than average.

“The water kept coming out, so our next plan was to block the flow away from where the main is located," Taylor said. "Some of the valves were inoperable, some broken, some we couldn’t locate very well because of all the water.”

Taylor said his team had to go deeper into the system to finally isolate the leak, an action which OWASA delayed in order to preserve other customers’ water supply.

“We were trying to avoid this as long as possible to minimize the number of customers affected, but this eventually worked,” he said.

Linda Low, OWASA’s communications director, said informing and updating the public was her team’s priority throughout the day. The OWASA website averages 350 visitors per day, but on Monday, visits skyrocketed to 31,000.

The broken water main was repaired Wednesday morning through a private contract with Moffat Pipe, a utility company based in Wake County. However, the fix is only temporary, as OWASA seeks to implement a new water-main pipe network at the breakage site sometime in 2019.

The main is currently crowded by two smaller pipes, which Taylor said could have contributed to the break.

“The initial look is to actually remove the three pipes and to put in a much simpler pipe with valves that are operational,” said Mary Darr, director of engineering and planning for OWASA. “We’ll have projects in the future to look at our transmission mains and the valves on our transmission mains, so we can respond quicker.”

Darr added OWASA has a consultant designing a new water prioritization model, which recommends replacing pipes by analyzing their risk of breaking. She said the fractured water main was not actually scheduled to be replaced, as other pipes had higher-risk scores under their current model.

John Young, a board member, asked Darr if the current system’s ability to accurately predict pipes most at risk in OWASA’s water distribution system is reliable. 

"Our current system is the median standard for the industry right now," Darr said.

OWASA has hired an independent consultant to analyze the cause of break and to judge the agency’s emergency actions. While there’s no definitive timeline on the report, Darr said a conclusion on the break’s cause could be reached within the next month.

@ryan_smooth

city@dailytarheel.com

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