On the morning of November 5, 2018, a water main break occurred on Jones Ferry Rd which affected water storage levels and water pressure in the system. Customers in OWASA's service area were asked to conserve water over a 24-hour period, and boil water before consuming it for a 30-hour period. Storage levels are back-to-normal and customers are using water as usual. We are investigating the cause of the break and will share information as it becomes available. We are very sorry for the inconvenience the event caused. We understand the community seeks to know more about what happened. Please find answers below to some of your frequently asked questions.
Frequently asked questions
What happened? Why did it take longer than usual to stop the loss of water?
A break occurred in a 16-inch pipe that carries water from the water treatment plant to the community. Factors such as the large volume of water flowing from the break, the depth of the break at 14 feet deep, and the pipe's location within a tight network of multiple pipes made it difficult to stop the water loss. We had to turn off valves and stop water flow at many different sections of the piping system in order to stop the leak, which took eight hours. We do not yet know the cause of the break. We are working with an independent consultant, Hazen & Sawyer, to investigate the cause and review our response. We expect their review to be complete mid-December and will share the information as soon as it is available.
Was it time for the pipe to be replaced? Do you have a system for maintaining and replacing pipes?
The pipe that broke was approximately 77 years old and is cast iron pipe. About 3% of our water pipes are made out of cast iron, and about 2% of our water pipes are 77 years or older. The American Water Works Association reports the average estimated service life for cast iron pipes at large water utilities in the South is 110 years old.
Our water main prioritization program prioritizes pipes to be upgraded and replaced based on industry assessment factors such as age, history of repairs and breaks, soil conditions, criticality of customers served, and pipe material. About 50 cents of every dollar of OWASA revenue is invested in renewing and replacing infrastructure. Our 5-year Capital Improvements Program includes $33 million dedicated to replacing 16 miles of water main pipes (4% of the distribution system).
In January 2018, we shared a report on water main breaks and strategies we use to reduce main breaks. We use hydraulic models, prioritization models, and geographic information systems to inform our decision-making. An average of 1.7 miles per year of new or replacement water mains have been installed over the past 10 years.
Why did OWASA ask all of its customers to conserve water?
Pipeline breaks typically only impact customers in the vicinity of the break. However, the size, location and duration of this break led to the loss of a lot of water from our storage tanks. We consider tanks to be at emergency levels if we drop to 2 million gallons. On November 5, storage levels dropped to 2.9 million gallons which is why we issued the “essential-use” advisory, to ensure we maintained enough water in the system in case of a community emergency. Customers were asked to conserve water over a 24-hour period. The community responded to the call and decreased their water use by 25%.
Why did OWASA ask all of its customers to boil water?
When water levels dropped, system pressure dropped too. When system pressure drops, contaminants can enter the system. Customers were asked to boil water over a 30-hour period. Boiling the water was a safety precaution until we could run tests to determine that no contaminants had entered the system. We tested 68 water samples throughout the community which were found to be clear and absent of bacteria. We lifted the boil water advisory immediately upon receiving the test results.
What will OWASA do next? How will OWASA make the system more resilient?
We are working with an independent consultant to investigate the cause of the break and review our response. We will share the information as soon as it is available. We are committed to being transparent about findings. We cannot anticipate every main break, but we can do more to bolster system resiliency. We plan to work with a consultant to verify that we are using industry best-practices, to ensure we are prioritizing asset management correctly, and to increase the resiliency of the system.
Our goal is to meet with community members and partners in the coming weeks and months, to invite community input and participation in decision-making on local water and wastewater priorities. We aim to understand better unique customer needs and develop solutions together for increased resiliency. We will share future plans as they develop, and we will work hard to earn back the community's trust.
Timeline of events
Updates during the event
Customers, community partners, and reporters asked OWASA to provide timely information on what was happening when. View the chronology of updates provided throughout the event, on www.owasa.org and on Twitter @OWASA1, here.
Update to the Chamber of Commerce
On November 11, 2018, the Chapel Hill-Carrboro Chamber of Commerce invited OWASA to meet with Chamber members. During this meeting, OWASA listened to how the Jones Ferry Rd water main break impacted community members, and shared information on what happened during the event. View the OWASA presentation to the Chamber of Commerce here.