Peirce Island Wastewater Facility Upgrade Project

The Peirce Island Wastewater Treatment Facility hosted a ribbon-cutting in July 2021 with EPA and other State and local officials and project contractors participating. As intended, this project significantly increased the level of wastewater treatment provided at the facility, resulting in improved effluent discharged to the Piscataqua River. The upgrade included the installation of new headworks, rotary screw presses for solids dewatering and an advanced secondary biological treatment process which removes organics and nitrogen, as outlined in this Fact Sheet. The $93 million project marks a milestone in the City’s history and with $81.9 million in state funding, is the largest in the history of the NH State Revolving Fund loan programs that support drinking water safety, water quality, and public health through low-cost financial assistance. As detailed in the Awards section, the upgrade project has received several awards for its completion under year-round weather conditions and without interruption to the continued operation of the existing treatment facility.Go to WWTF tour video

Peirce Island Wastewater Treatment Facility has received the following awards:

2023 NH DES plant of the Year
2022 American Council of Engineering Companies of MA Project Excellence Award for the Silver
Water Environment Federation (WEF) Project Excellence Award
Associated Builders and Contractors of New Hampshire and Vermont (ABC NH/VT) Excellence in Construction Award and Chairman’s Award

Progress videos are available on our YouTube page, shown below.

Project Contact

Erich Fiedler

City Engineer

603-766-1421

esfiedler@portsmouthnh.gov

DEDICATION JULY 13, 2021

For information about the dedication event, click here.

PROJECT FACTSHEET

Start Date: September 2016
BAF Substantial Completion: December 2019
Secondary Permit Compliance: April 2020
Project Substantial Completion: July 2021
Final Completion: 2021 (under review)
Project Construction Costs:
- Base Contract: $72,785,545.00
- Change Order No. 1: $367,290.42
- Change Order No. 2: $546,722.46
- Change Order No. 3: $ 93,838.31
- Change Order No. 4: $162,869.20
- Change Order No. 5: $249,828.16
- Change Order No. 6: $292,031.11
- Change Order No. 7: $169,138.30
- Change Order No. 8: $112,659.75
- Change Order No. 9: $242,419.68
- Change Order No.10:$122,783.46
- Change Order No.11:$138,938.61
- Change Order No.12 $834,356.28
- Total Contract: $76,118,420.74
Design Engineer: AECOM
General Contractor: Methuen Construction
Design Flow: 6.1 MGD average
New Treatment Processes:
- New Headworks
- Biologically aerated/anoxic filter (BAF) using the Kruger BioSTYR ™ technology for Secondary Treatment and Nitrogen Removal
- Rotary screw presses for solids dewatering
- Simplified Process Flow Schematic