Exeter, NH
Exeter Wastewater Treatment Facility Upgrade
Nutrient removal and wastewater conveyance
Exeter replaced an aerated lagoon process with a plant designed for biological nitrogen removal. The upgrade also rebuilt critical conveyance infrastructure serving the Squamscott River and Great Bay watershed. [1] [2]
- Total upgrade cost [1]
- $53.5M
- Plant design flow [1]
- 3M gal/day
- Residents served · 2022 [4]
- 12,736
- Plant contract amount, as reported by Apex [3]
- $36.87M
Why it happened
Exeter needed to address aging treatment infrastructure and reduce nitrogen entering the Squamscott River and Great Bay. The town serves wastewater customers in Exeter and portions of Stratham and Hampton. [2] [5]
What was built
The plant uses a four-stage Bardenpho process for biological nitrogen removal. The program also upgraded the main pump station, installed two force mains, and added a septage receiving station. [1] [2]
What changed
EPA reports that nitrogen levels fell within a month of startup in June 2019. The agency also credits the continued use of the existing lagoons and the main pump station upgrade with eliminating most of the town’s combined sewer overflows. [2]
Project team
- Owner
- Town of Exeter [1]
- Plant construction · Contract 1
- Apex Construction [3]
- Precast package
- Dutchland
My role
I managed the schedule, fabrication, and field installation for the precast package, which included a 70-foot clarifier.
Project photos
Site location
See the upgraded treatment basins beside the former lagoon area and the Squamscott River.
Project records
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Wright-Pierce · Exeter wastewater upgrades
Program scope, treatment process, plant capacity, and total upgrade cost.
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EPA · Clean Water State Revolving Fund case study
Financing, nitrogen removal, and combined sewer overflow results.
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Apex Construction · Project qualifications filed with Biddeford
Plant contractor, engineer, completion date, and contractor-reported contract amount.
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EPA · 2022 Clean Watersheds Needs Survey
Residential population reported for the treatment facility in the 2022 Clean Watersheds Needs Survey. View facility survey data (JSON)
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Wright-Pierce · Engineering project profile
Service area, plant design, and engineering scope.
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Piscataqua Region Estuaries Partnership · Construction report
A record of the upgrade during construction.