A water main breaks every two minutes in the U.S., wasting more than two trillion gallons of treated drinking water annually, according to the American Society of Civil Engineers 2021 Report Card for America’s Infrastructure. These events can lead to negative water pressure in the system, which increases the risk of contamination. Water advisories are used to limit water consumption, but consumer compliance with advisories is critical to maintain pressure and avert the need for boil water orders.

Professor Emily Berglund and Ph.D. student Morgan DiCarlo worked with the Orange County Water and Sewer Authority (OWASA) in North Carolina to explore how customers complied with a recent water advisory using water consumption data collected through Advanced Metering Infrastructure (AMI). AMI provides high temporal and spatial resolution of water consumption data, which are analyzed to identify changes in water use behaviors.

The main pipe leaving OWASA’s water treatment plant broke in November 2018, leading to a loss of pressure and decreased storage levels in water tanks. More than 80,000 people in the community were asked to limit water use to essential purposes only through texts, phone calls and local news media. OWASA had previously installed AMI smart meters, which record hourly water use at customer accounts, and shared hourly water consumption data from 16,000 smart meters with the NC State research team. Researchers calculated per capita essential water use based on the essential water needed for hygiene, cooking and toilet flushing.

Through analysis of smart meters and occupancy data, researchers found that about 30% of the households reduced their water consumption to essential use. As a result, water use was reduced by 27% during periods of peak water use and by 16% across the duration of the event.

“Utilities need an understanding of household-level responses during water service disruptions to enhance resilience and mitigate consequences. AMI data can be analyzed to gain insight about customer compliance during water service interruptions and subsequent water advisories.”

Emily Berglund

This research identified that the way people interpret ”essential uses” for water can affect compliance rates of water advisories. Utilities can reevaluate the language used in communicating water advisories to emphasize the importance of compliance to reduce susceptibility to waterborne illnesses and other health risks.

This research was published in Water Research in August 2022 (doi.org/10.1016/j.watres.2022.118802).