Wastewater Treatment Process

The Wolfeboro Wastewater Treatment Facility is managed by the contract operations firm Woodard & Curran and they are currently entering into the 5th year of a 5 year contract. This treatment facility is staffed with 3 full time certified operators and assisted by part time employees on an as needed basis. The Facility was constructed in the early 1970’s and is an Activated Sludge Process. The facility receives most of the raw wastewater from the Mill Street Sewage Pump Station, which can pump up to 1,400 gallons per minute. The Facility is permitted for 600,000 gallons a day; currently we are averaging about 385,000 gallons per day.

The Treatment Process consists of a head works building for grit and rag removal (currently being upgraded with a new head works screen). Wastewater flows to a distribution box where it is combined with returned activated sludge (RAS) and directed to one of four 90,000 gallon aeration tanks for biological treatment, then to 2 – 25 foot diameter secondary clarifiers. Clear effluent from clarifiers is chlorinated and pumped to the 90 million gallon treated effluent storage pond. The treated effluent is then pumped to the newly constructed Rapid Infiltration Basins where it infiltrates into the ground.

Waste activated sludge is thickened and stored in two sludge holding tanks and hauled by truck for final disposal off site.

Equipment and Process upgrades over the last 3 years have allowed operators to run the plant in a Biological Nutrient Removal mode, that is, the plant is now able to produce an effluent which averages below 5 mg/l of Total Nitrogen and below 1 mg/l Total Phosphorus under current flow and load conditions. If you have any questions about the facility, please contact Director of Water and Sewer Utilities, David Ford, PE at 569-8176.