Portsmouth, NH — The City of Portsmouth’s Department of Public Works is inviting the public to an open house at the Peirce Island Wastewater Treatment Facility (WWTF) and newly completed Road Resiliency Project on Saturday, May 31, 2025, from 10 a.m. to 1 p.m. Guided tours led by city staff will offer a behind-the-scenes look at the City’s wastewater treatment process and recent infrastructure upgrades.
Originally reopened in July 2021 after a $93 million upgrade—the largest project in the City’s history—the Peirce Island WWTF now delivers significantly enhanced wastewater treatment and cleaner discharge to the Piscataqua River. The project also stands as the largest ever funded through New Hampshire’s State Revolving Fund loan program and earned the 2023 NH DES Plant of the Year award.
Guests will also learn about the Peirce Island Road Resiliency Project, which elevated a 400-foot section of roadway and adjacent parking to guard against sea level rise. Visitors should park in the new lot near the facility gate.
Because the WWTF is a working plant, the open house is limited to adults. Attendees should wear sturdy shoes and note that the tour involves outdoor areas with uneven terrain and no restroom facilities. Those needing mobility assistance should contact Lori-Ann Dixey at 603-766-1446 or ldixey@portsmouthnh.gov at least 48 hours in advance. There is no rain date.
For more details, visit the City’s website at portsnh.co/peircewwtf or contact City Engineer Erich Fiedler at esfiedler@portsmouthnh.gov.
