The advisory impacts customers in the town's central water zone, including downtown Hillsborough, West Hillsborough, the north side of U.S. 70A to Lawrence Road (excluding Forest Ridge), and the Tuscarora and Morelanda Drive areas.
Town officials said a 6-inch water main leak on Elizabeth Brady Road caused the pressure issues. As a precaution, affected customers should boil water used for drinking, cooking and brushing teeth until further notice.
The town is purchasing water from Durham to help restore water levels in a tank on Hasell Street. Officials expect pressure problems to be resolved by Saturday afternoon.
All Hillsborough water customers are also being asked to conserve water. Residents are urged to avoid activities such as watering lawns, washing cars and pressure washing until further notice.
Town officials said restaurants and childcare centers have procedures in place for operating during a boil water advisory, though some businesses may choose to close temporarily.
The town said testing will be conducted before the advisory can be lifted.
Residents who are unsure whether they are in the affected area can contact the Water Treatment Plant at 919-732-3621.