Westborough Wastewater Treatment Plant
Westborough, MA · Worcester County · Publicly Owned Treatment Works
- Average flow
- 4.17 MGD
- Design flow
- 7.7 MGD
- NPDES permit
- MA0100412
- Effective
- Permit expires
- April 2027
- Population served
- 51,131
- CWNS 2022
Westborough Wastewater Treatment Plant is a publicly owned wastewater treatment works in Westborough, Worcester County, Massachusetts treating an average of 4.17 million gallons per day against a permitted design capacity of 7.7 MGD, serving about 51,131 residents. Treatment on site includes clarifiers, carrousels / oxidation ditches, biogas balloons, biological n removal, biological p removal and other unit processes. It discharges under NPDES permit MA0100412 (effective), which expires in April 2027, with 2 recorded violations in the last three years.
Treatment technology
Treatment structures identified at this facility. Exact unit counts are available in Klarifi.
Clarifiers
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Carrousels / oxidation ditches
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Biogas balloons
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Biological N removal
unit processBiological P removal
unit processBiological Treatment, Other
unit processBiosolids Chemical Addition
unit processBiosolids Incineration
unit processBiosolids Mechanical Dewatering
unit processBiosolids Thickening
unit processChemical Addition, Alum
unit processChemical Addition, Polymer
unit processDisinfection, UV
unit processPrimary Clarification or Sedimentation
unit processScreening
unit processUnlock exact unit counts →
Compliance snapshot (last 3 years)
- Total violations
- 2
- Effluent violations
- 2
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
Capital improvement projects in Westborough
Westborough's capital improvement plan lists 12 water, sewer and wastewater line items worth $19M starting 2026–2028. The largest budgeted items are shown here.
All water and sewer capital projects in Westborough →
| Project | Budget | Years |
|---|---|---|
| Sewer Pump Station Improvements | $7,700,000 | 2026–2030 |
| Sewer Line Analysis | $3,060,000 | 2026–2028 |
| Water Main Replacement | $2,850,000 | 2027–2030 |
| Well and Booster Station Improvements | $1,800,000 | 2026–2030 |
| Water Tower Maintenance | $1,200,000 | 2027–2029 |
Full project details — scope, funding source, engineering consultant and the decision-makers behind each project — are available in Klarifi, along with similar wastewater capital projects in other cities.
Key contacts
3 verified contacts for Westborough Wastewater Treatment Plant, with validated emails and direct phone numbers.
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Names, validated emails and direct phone numbers for decision-makers at Westborough Wastewater Treatment Plant, plus the full compliance history and discharge data.
Nearby wastewater treatment plants in Massachusetts
Marlborough · 4 mi away
1.16 MGD
Marlborough · 9 mi away
2.04 MGD
Millbury · 9 mi away
24.1 MGD
Hudson · 10 mi away
0.78 MGD
East Douglas · 14 mi away
0.13 MGD
Leicester · 15 mi away
0.09 MGD
North Oxford · 15 mi away
0.17 MGD
Wayland · 15 mi away
0.03 MGD
Westborough Wastewater Treatment Plant: frequently asked questions
Sources and methodology
Flow, permit and violation figures come from the EPA's ICIS-NPDES discharge monitoring records. Population served comes from the Clean Watersheds Needs Survey 2022. Treatment structures are identified by Klarifi's review of aerial imagery, and capital improvement projects are extracted from published municipal budget documents. Violations are counted over the last three years of monitoring reports.
Data refreshed September 11, 2026; facility record last updated March 6, 2025.