Cohasset Wastewater Treatment Facility
43 Elm St, Cohasset, MA 02025 · Norfolk County · Publicly Owned Treatment Works
- Average flow
- 0.18 MGD
- Design flow
- —
- NPDES permit
- MAG580033
- Effective
- Permit expires
- November 2026
- Population served
- 4,646
- CWNS 2022
Cohasset Wastewater Treatment Facility is a publicly owned wastewater treatment works in Cohasset, Norfolk County, Massachusetts treating an average of 0.18 million gallons per day, serving about 4,646 residents. It discharges under NPDES permit MAG580033 (effective), which expires in November 2026, with 82 recorded violations in the last three years.
Treatment technology
9 treatment structures and unit processes identified at Cohasset Wastewater Treatment Facility.
Available with a free Klarifi account
See the full treatment train at Cohasset Wastewater Treatment Facility: structures, unit processes and planned upgrades, with exact unit counts.
Compliance snapshot (last 3 years)
- Total violations
- 82
- Effluent violations
- 72
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
EPA enforcement history
Federal civil enforcement cases, compliance inspections and informal actions recorded for Cohasset Wastewater Treatment Facility in EPA's ICIS system.
- Formal actions
- 0
- none on record
- EPA inspections
- 1
- latest May 2007
No formal federal enforcement case is on record for this plant.
Full case history with a free Klarifi account
Every action against Cohasset Wastewater Treatment Facility with dates, milestones, violation types and EPA's complete case summaries, plus inspections and informal actions.
Key contacts
17 verified contacts for Cohasset Wastewater Treatment Facility, with validated emails and direct phone numbers.
Unlock 17 verified contacts (14 more than shown)
Names, validated emails and direct phone numbers for decision-makers at Cohasset Wastewater Treatment Facility, plus the full compliance history and discharge data.
Nearby wastewater treatment plants in Massachusetts
Hull · 7 mi away
1.53 MGD
Rockland · 10 mi away
2.21 MGD
Winthrop · 11 mi away
270.96 MGD
Brockton · 17 mi away
14.52 MGD
Salem · 20 mi away
21.66 MGD
Bridgewater · 21 mi away
0.17 MGD
Plymouth · 23 mi away
1.08 MGD
Manchester · 23 mi away
0.44 MGD
Cohasset Wastewater Treatment Facility: 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 October 26, 2026; facility record last updated September 23, 2025.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Ozonation · Activated sludge · all terms