Nashua WWTP
2 Sawmill Rd, Nashua, NH 03060 · Hillsborough County · Publicly Owned Treatment Works
- Average flow
- 9.77 MGD
- Design flow
- 16 MGD
- NPDES permit
- NH0100170
- Administratively continued
- Permit expires
- May 2020
- Population served
- 99,918
- CWNS 2022
Nashua WWTP is a publicly owned wastewater treatment works in Nashua, Hillsborough County, New Hampshire treating an average of 9.77 million gallons per day against a permitted design capacity of 16 MGD, serving about 99,918 residents. It discharges under NPDES permit NH0100170 (administratively continued), which expires in May 2020, with 78 recorded violations in the last three years. EPA has recorded 2 formal enforcement actions naming the plant, the latest in December 2005.
Treatment technology
3 treatment structures and unit processes identified at Nashua WWTP.
Available with a free Klarifi account
See the full treatment train at Nashua WWTP: structures, unit processes and planned upgrades, with exact unit counts.
Compliance snapshot (last 3 years)
- Total violations
- 78
- Effluent violations
- 60
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 Nashua WWTP in EPA's ICIS system.
- Formal actions
- 2
- 0 since FY2020
- Compliance actions
- $77M
- required by EPA orders
- EPA inspections
- 0
- none on record
Latest case · Dec 2005
NASHUA CITY OF
Judicial case · CWA, NPDES Discharge without a Permit · Final Order No Penalty · Compliance actions $65M
Source: EPA ECHO, civil enforcement case 01-2003-0163.
Full case history with a free Klarifi account
Every action against Nashua WWTP with dates, milestones, violation types and EPA's complete case summaries, plus inspections and informal actions.
Capital improvement projects in Nashua
Nashua's capital improvement plan lists 16 water, sewer and wastewater line items worth $83M starting 2026–2028. The largest budgeted items are shown here.
All water and sewer capital projects in Nashua →
| Project | Budget | Years |
|---|---|---|
| Class A Biosolids | $25,500,000 | 2027–2027 |
| Annual Sewer Infrastructure Improvements Programs | $24,237,000 | 2026–2031 |
| WW Plant Vehicle Garage | $10,800,000 | 2026–2027 |
| WWPlant Phase I | $6,192,000 | 2026–2026 |
| Annual Stormwater Management/Abatement | $4,851,000 | 2026–2031 |
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
11 verified contacts for Nashua WWTP, with validated emails and direct phone numbers.
Unlock 11 verified contacts (8 more than shown)
Names, validated emails and direct phone numbers for decision-makers at Nashua WWTP, plus the full compliance history and discharge data.
Nearby wastewater treatment plants in New Hampshire
Merrimack · 5 mi away
1.29 MGD
Derry · 10 mi away
1.46 MGD
Milford · 11 mi away
1.14 MGD
Hooksett · 22 mi away
0.82 MGD
Allenstown · 26 mi away
0.53 MGD
Epping · 28 mi away
0.18 MGD
Concord · 30 mi away
3.5 MGD
Exeter · 31 mi away
1.45 MGD
Nashua WWTP: 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 April 5, 2025.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Significant industrial user · WWTP · all terms