New Sewer Upgrades

Wastewater treatment: The Newington Wastewater Treatment Plant (NWWTP) opened for operations in 1981 with a design flow of .290 million gallons a day. The plant operates as a secondary activated sludge process and with EPA and DES permits (# NHG581141), the plant discharges treated water into the Piscataqua River. The system has 11 miles of sewer pipe and exclusively serves the Town’s commercial, industrial and waterfront industrial uses. The Town upgraded the plant in 2016 – 2018 with a 20 year $8,700,000 bond. In 2020, the plant received a force main upgrade. In 2005, the NWWTP received an EPA award for Best Operated and Maintained Facility. A full time certified manager supervises the day to day operations of the plant and the Newington Sewer Commission, elected by the voters, is responsible for the governance and overall management of the plant. At present, the plant operates at approximately 50% capacity. The Town is fortunate to have a modern and well managed facility.

Water supply: The Town requires all single family homes and new commercial and industrial development to connect to a public water supply. The Portsmouth regional water system provides water supply to the City of Portsmouth, Towns of Newington, New Castle, Greenland and portions of Rye and Madbury along with the Pease International Tradeport. The system is committed to provide customers with an adequate water supply to meet both current and long-term water needs. The Pease water system and the Portsmouth water system are separately operated in terms of supply and distribution, but interconnected so that supply can be supplemented between the systems as needed. The Madbury reservoir and the city’s six other wells supply the Portsmouth water system.

Efforts to optimize water supply have been undertaken for many years. Long-range planning studies, performed every 10 years, guide the system’s capital and operational upgrades. Past improvements include the upgraded Madbury water treatment facility in 2011, the replacement and pumping upgrades at the Greenland well in 2017 and the installation of new booster pumps at the Newington booster station in 2019. Recent water supply projects are due to come on-line soon to support long-term municipal water needs. These include the start-up of Well Number 5 in Madbury, which was permitted in 2018, and construction of additional water storage capacity at the Madbury water treatment facility, which will allow for more steady and efficient flow from that source.

Long-term water supply planning and efficient management of existing water supply resources is the everyday work of the Portsmouth Water Division. The state of New Hampshire recognized the City’s work with its 2015 Water Sustainability Award. Detailed information on the city’s water supply can be found at

Electricity: To help ensure that the New Hampshire Seacoast Region will continue to grow, Eversource completed construction of the Seacoast Reliability Project, a new transmission line connecting two existing substations. The project includes a new 115-kilovolt (kV) transmission line extending approximately 13 miles between substations in Madbury and Portsmouth, N.H., along with associated substation upgrades. The project became operational on May 29, 2020. The new transmission line will improve electric service in the Seacoast area so that customers will have reliable electric power to meet current and growing energy needs. The project ensures that the region’s electric grid conforms to national and regional reliability standards.

Eversource invested more than $123 million in this New Hampshire project. The cost of the project will be paid by all electric customers in New England. A key component of the project is the underwater connection between Durham and Newington.