An operator at the Town of North Brookfield wastewater treatment plant led a facility walkthrough and explained how recent upgrades changed monitoring and control — while noting several major pieces of legacy equipment remain in need of replacement.

The operator described the treatment train from headworks to outfall, showing two samples to demonstrate the difference between raw influent and treated effluent. “This is essentially what we call influent. This is what comes into the facility,” he said, and later, “This is essentially our final product. This is what goes out to the stream.” He emphasized that bacteria in the aeration basins perform most of the treatment and that secondary clarifiers are critical to keep those bacteria in the plant and out of the Forget Me Not Brook.

Why it matters: the plant must meet discharge permit limits from the Department of Environmental Protection (DEP) and U.S. Environmental Protection Agency (EPA). The operator said permit limits are reissued every five years and tightened recently, which was a primary driver of upgrades. He said the plant was upgraded enough to achieve compliance for several months, but some older equipment — notably the two secondary clarifiers — were not replaced because of budget limits.

Upgrades, automation and operation
The walkthrough highlighted new laboratory space, automated sensors (dissolved oxygen, ammonia, ORP, TSS), flow meters, and converted basins with baffle walls that create zones targeting phosphorus, nitrogen and biochemical oxygen demand. The operator described an automation system that adjusts blowers and pumps in real time based on sensor readings: “Everything’s automated now … these machines will speed up and slow down based off of the concentration of pollutants.”

He showed a composite sampler that collects 96 samples (every 15 minutes over 24 hours) to create the daily composite required for state reporting and said the plant reports results to the state for compliance verification.

Aging clarifiers, parts obsolescence and maintenance
The operator said the secondary clarifiers were not addressed in the recent capital project and remain nearly 35 years old with obsolete parts and leaking seals. He warned repairs are difficult because parts are no longer manufactured and replacement is likely necessary: “They’re original. They’re almost 35 years old, and they’re in pretty rough shape.”

Sludge handling and rising disposal costs
The plant dewaters sludge with a belt filter press and ships biosolids off-site for incineration. The operator said hauling and disposal of solids is the largest line item in the sewer budget, estimating roughly $4,000,000 per year for disposal and noting that disposal costs have risen substantially over the last decade (from about $105 per wet ton to roughly $185 per wet ton, as stated). He identified tightening EPA limits and the presence of PFAS in biosolids as major factors increasing disposal complexity and cost.

Septage receiving and operational improvements
New septage receiving infrastructure — a receiving building with swipe-in controls and 20,000-gallon holding tanks (operator-stated capacity 40,000 gallons) — allows the plant to accept and meter trucked septage without slugging the biological trains. Operator said this reduces operational upset and protects treatment performance.

Capacity and policy implications
The operator said the plant is designed to treat about 800,000 gallons per day and is currently treating roughly 350,000 gpd (less than half of design). He noted DEP policy that generally limits new sewer connections when a plant reaches about 80% of design flow, and said additional customers would spread fixed costs and help rate pressure.

What’s next
No formal votes or policy decisions were recorded as part of this walkthrough. The operator identified capital needs (replacement of secondary clarifiers and older pumps/piping) and ongoing operational pressures (PFAS-driven disposal limits, rising hauling costs). He emphasized continued monitoring and daily operator attention to keep the plant in compliance.

Sources and attribution
Reporting is based entirely on comments made during the plant walkthrough by an unidentified plant operator representing the Town of North Brookfield.

The committee/town did not take formal action during the walkthrough; regulatory oversight and permit renewal remain the next standing steps for continued compliance.