Construction is imminent for wastewater treatment facility (WWTF) upgrades at a small town in New Hampshire! With over 4,000 residents in Allenstown, upgrades may not seem as critical as they would for larger municipalities, but Allenstown’s sewer system shares its services with Pembroke (over 7,000 residents) and discharges to the Suncook River just before it joins the Merrimack River. With the Merrimack River watershed affecting approximately 200 communities in New England, protecting and being stewards of water quality is critical. Hoyle Tanner has been working with the Allenstown Sewer Commission since 2023 to study the facility’s performance with upgrades ready to be constructed starting this month, October 2025.
Study Results & New Design
After Hoyle Tanner’s analysis, we recommended that the existing clarifiers, which are shallow and inadequate for the community’s needs, be supplemented with two new (larger) clarifiers. Our study paved the way for project funding for construction. The design included the two new clarifiers, site utility relocation, site drainage and paving improvements, upgrades to sludge pumping capacity, relocation of the plant water system, and environmental permitting.
Project Timeline
The project was competitively bid in May 2025. Four contractors submitted bids and Penta Construction of Moultonborough, New Hampshire was awarded the project. Construction begins this month and will extend through summer 2027.
Funding
Infrastructure projects that affect public health and the environment can have a big price tag. This $11 million construction project is being funded by the NHDES Clean Water State Revolving (CWSRF) loan. The CWSRF program receives federal funds that are distributed state-wide to communities with wastewater infrastructure helping to pay for wastewater and drinking water projects. For a project to get funded, it must meet specific requirements and meet criteria outlined in the program’s Intended Use Plan (IUP). Hoyle Tanner’s experience with the CWSRF (and other funding programs) program helped us guide Allenstown to make project decisions that maintained funding eligibility throughout planning, design, and construction.
Hoyle Tanner’s Role
Hoyle Tanner will provide construction administration and resident observation services to the Allenstown Sewer Commission throughout the construction phase. Hoyle Tanner provides a full range of planning, design, and construction services for wastewater collection and treatment projects. We partner with our clients to find solutions that are energy efficient, sustainable, and cost conscious. We’re thrilled to bring this project to life in Allenstown and can’t wait to see the positive impact it will have on residents who rely on the WWTF. If there’s a project in your community that could use our services, please head to our website and learn more about what we do.
