The Town of Hillsborough, North Carolina, treated 369.4 million gallons of wastewater during fiscal year 2026 while maintaining compliance with permitted limits for most regulated parameters, according to its annual wastewater quality report.

The town reported one notice of violation after a weekly BOD sample measured 20.2 mg/L in April, exceeding the permitted weekly limit of 7.5 mg/L. A second sample taken two days later was below the detectable limit, and the town attributed the result to a suspected laboratory error. No civil penalty was assessed.

The plant recorded an average daily flow of 1.021 million gallons per day and a maximum monthly flow of 1.254 mgd, compared with permitted maximum monthly flow of 3 mgd. Total nitrogen discharge fell to 5,722 pounds for the year, down from 6,876 pounds in fiscal 2025, while total phosphorus declined to 648 pounds from 877 pounds.

Hillsborough is planning additional collection system and treatment infrastructure improvements. The town plans to resume a wastewater treatment plant master plan after anticipated revisions to North Carolina’s Falls Lake Rules in 2027. The plan will evaluate future treatment technologies and upgrades needed to meet nitrogen requirements.

The town also plans rehabilitation of its Eno River interceptors, which are affected by hydrogen sulfide corrosion and significant inflow and infiltration. Construction is scheduled to begin on the east side in fiscal 2027 and the west side in fiscal 2029. Other projects include rehabilitation of the Lawndale sewer basin, upgrades to the Exchange Club interceptors and improvements to the Elizabeth Brady Pumping Station and force main.

The report also highlights the impact of Tropical Storm Chantal, which caused four sanitary sewer overflows in July 2025 after flooding inundated the River Pumping Station. The station, which handles about 75% of the town’s wastewater, required bypass pumping for six months and more than $800,000 in restoration work.