The City of Haverhill, through its Wastewater Division, owns and operates a wastewater treatment plant (WWTP) and sewer collection system. Wastewater collected throughout the city is conveyed to the WWTP by its interceptor piping network.
The sewer collection system is comprised of separated and combined sewers. Separated sewers, primarily located outside of the densely populated downtown areas, only convey sanitary flow. Combined sewers convey both stormwater and sanitary flow through the same pipe. Dry weather flow and a portion of the wet weather flow are conveyed to the WWTP and excess wet weather flow is discharged out of the CSO outfalls.
The WWTP is located off of South Porter Street. It provides primary treatment, secondary treatment and disinfection of wastewater prior discharging it to the Merrimack River. The WWTP has an average day design capacity of 18 million gallons per day (mgd) and a peak wet weather flow capacity of 65 mgd.
The City operates and maintains its sewer system under NPDES Permit No. MA0101621 issued by the U.S. Environmental Protection Agency (EPA) and the Massachusetts Department of Environmental Protection (MassDEP) and a Consent Decree (Civil Action No. I6-II698-IT) between the United States, Commonwealth of Massachusetts and the City of Haverhill lodged in U.S. District Court on November 10, 2016.