Agenda - 02-19-2019 4-a - OWASA Annual Update Presentation

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OWASA Annual Report 3 January 29, 2019 Page 2 Hurricane Florence In the lead-up to Hurricane Florence, OWASA reviewed its response, safety, and staffing plans; secured back-up fuel and treatment chemicals; lined up contractors to assist with repairs as needed; assigned Incident Command responsibilities; and coordinated with community partners. On September 14, Florence made landfall in North Carolina as a Category 1 Storm. University Lake peaked at 54.5 inches above the spillway triggering the first stage in OWASA's Dam Emergency Action Plan(EAP). At this first stage, there is no real danger of the dam failing; however as per EAP protocol, OWASA notified Orange County Emergency Management, the dam's engineer, and the state. The State Department of Environmental Quality's Dam Safety Division inspected the dam and noted no issues. Cane Creek Reservoir's water levels peaked at 27.5 inches above the spillway; this did not require OWASA to activate the Dam EAP. OWASA responded to two water main breaks and restored service to affected community members (88 customers)within the day. Stormwater inadvertently entered the wastewater collection system resulting in one wastewater overflow(estimated at 8,300 gallons). Hurricane Michael With preparations for Hurricane Florence still intact, OWASA was ready for Hurricane Michael. On October 11, power outages started to occur in Carrboro and Chapel Hill. By 6:30 pm that evening, OWASA had twelve facilities running smoothly on back-up power generation: the Cane Creek Reservoir raw water pump station, the water and wastewater treatment plants, and 9 wastewater pumping stations. Throughout the storm, all water and wastewater systems remained fully operational. On October 13, recreation was closed at Cane Creek Reservoir due to power limitations. By October 14 at 1:15 pm,utility power was restored and we returned to normal operations at all locations. Jones Ferry Road Water Main Break On November 5, 2018, a water main break on Jones Ferry Road in Carrboro affected water storage levels and system pressure. Customers in OWASA's service area were asked to conserve water for 24 hours and boil water(before consuming it) for 31 hours. Immediately following the event, OWASA commissioned engineering firm Hazen and Sawyer to conduct an independent review of what caused the break and why it took 7.5 hours to stop the leak. According to Hazen and Sawyer, the root cause of the main break was a manufacturing defect in the pipe. The area where the pipe cracked was significantly thinner than other areas of the pipe. This defect, compounded with the age and material of the pipe,resulted in localized cracking. To stop the leak, OWASA had to close a series of valves. Some valves were found to be inoperable requiring OWASA to move further away from the break to close more valves. The report noted that the complexity of turning 31 valves overall resulted in 7.5 hours passing before OWASA slowed the leak to a point where the necessary repairs could be made. OWASA is acting on recommendations from the report to increase system resiliency. For example, we are establishing a dedicated valve maintenance crew,working with a consultant to improve the organization's water pipe assessment and replacement prioritization model, and developing plans to improve piping infrastructure leaving the Water Treatment Plant (WTP) on