South Woodstock WWTF Upgrade
Woodstock VT WWTF Upgrade
Hoyle Tanner completed the preliminary engineering study to upgrade the South Woodstock WWTF. The original WWTF was a 50,000 gpd package conventional activated sludge facility that had not been upgraded since 1966. Redundancy was not provided for process tankage including the aeration basin and secondary clarifier. Therefore, the process units could not be taken offline for tank inspection or repair. The facility is now required to nitrify and denitrify with an effluent Total Nitrogen (TN) limit in the NPDES permit. Additionally, a portion of the WWTF site is in the Regulatory Floodway, creating significant limitations on siting new process tankage.
For the upgrade of the WWTF, three process alternatives were considered: Sequencing Batch Reactor (SBR), Membrane Bioreactor (MBR), and submerged attached growth bioreactor (SAGB). The alternatives were evaluated based on a life-cycle cost analysis and non-monetary factors. The recommended alternative was an SBR process with an innovative equipment layout, allowing all process equipment to be accessed from above the water line. This allowed for a two-tank SBR process without pre-equalization to meet the Vermont DEC SBR design guidelines. This innovative approach saved capital cost while realizing a lower life-cycle cost, as well. The new facility was constructed and put into service prior to decommissioning the original facility. Construction of the new SBR facility was completed in 2023.
- Study
- Alternatives Development & Analysis
- Preliminary Design
- Permitting
- Funding Assistance
- Public Outreach
- Final Design
- Bid Process Administration
- Construction Administration
From the blog
Learn about ongoing projects and the innovative processes we employ for our clients.
The Windy Path of an Engineer: Challenges, Lessons & Triumphs
June 24, 2025
Having graduated from the University of Vermont four years ago, I find myself reflecting on where I was, where I am today, and where I will be in four...
Read More
Stephen Langevin Joins Ground Transportation Division
June 24, 2025
Help us extend a warm welcome to Steve Langevin, PE, who joins us a Senior Structural Engineer (and project manager) in our Ground Transportation Division! Steve is a highly...
Read More
Civil Engineering Solutions for Peterborough’s First Responders
June 18, 2025
Construction is set to begin at Peterborough’s new state-of-the-art Fire Station, located on Elm Street. The existing Summer Street facility was outdated, undersized, had limited access, and was no...
Read More
Revitalizing the Amoskeag Bridge: Keeping the City Connected & Moving
June 13, 2025
The Amoskeag Bridge in Manchester, New Hampshire, is undergoing a significant rehabilitation project aimed at extending its service life. Constructed in 1970, the bridge is now 55-years-old and serves...
Read More
From Spare Change to Food Banks: Charitable Contributions in May
June 13, 2025
Hoyle Tanner is always looking for ways to give back to our local communities, so throughout the month of May we held a Penny War to add a competitive...
Read More
Welcome Matthew Elia, CM – Senior Airport Planner
June 12, 2025
We are pleased to welcome Matthew Elia, CM, to Hoyle Tanner as a Senior Airport Planner in our Airport Services Division! Matt brings more than a decade of hands-on...
Read More
From Seacoast to Westbrook: Continuing a Partnership in Housing Innovation
June 9, 2025
From golf course to housing infrastructure, Hoyle Tanner is again working with Jones Street Residential to satisfy housing needs in Maine! This project is not only addressing needed infrastructure,...
Read More
Employee Spotlight: Jenae Carraway
June 9, 2025
Meet Jenae Carraway, PE - Senior Transportation Engineer & Seeker of the Perfect Pastry What drew you to Hoyle Tanner? When I was interviewing last year, I talked to...
Read More
Leading with Purpose: Why We Invest in Our Principals
June 5, 2025
At Hoyle Tanner, leadership is more than a title—it’s a commitment to continual growth, intentional guidance, and long-term client and team success. As part of that commitment, several of...
Read More