New Hampshire NPDES permit search
Status, expiry and violations for 47 municipal wastewater permits · issued by EPA Region 1
In short
How do I look up an NPDES permit in New Hampshire?
Search this page by permit number or plant name for a municipal plant’s permit status, expiry date and violations. For the official file, search EPA’s list of New Hampshire permits or NHDES OneStop. EPA’s ECHO database shows the monitoring results and violations of every permit. The 67 industrial permits in New Hampshire are listed in Klarifi with a free account.
Links to official sources checked September 2026.
Effective
30
Administratively continued
11
Expired
6
Plants with effluent violations, 3 years
41
Where to find official New Hampshire NPDES records
New Hampshire has not taken over the NPDES program: EPA Region 1 issues and enforces the permits and keeps the official file, with the state agency handling water-quality certification. EPA Region 1 website ↗
permit documents
EPA Region 1’s table of final permits. Type the facility name, town or permit number (for example NH0100447) in the search box and click the facility to open the permit.
permits
NHDES’s environmental database; start from “OneStop Basic Search” on its navigation page.
permits · DMRs · inspections · violations · enforcement
EPA’s Enforcement and Compliance History Online. Search water facilities by permit number, name or city; the Detailed Facility Report lists inspections, violations and enforcement actions, and Effluent Charts plot monitoring results against the permit limits.
- Discharge monitoring reports
- Through EPA’s NetDMR, usually by the 15th of the following month; municipal plants attach their NHDES monthly operating reports.
Industrial and commercial NPDES permits in New Hampshire
Most NPDES permits are not held by municipal plants. EPA’s permit database lists 67 individual permits in force for industrial and commercial facilities in New Hampshire (manufacturers, food processors, mines, power plants, landfills), 14 of them major dischargers, plus 274 facilities covered by a general permit, mostly for stormwater. 16 of the individual permits recorded at least one effluent violation in the last three years.
| Facility | Permit | Status | Expires | Effluent violations |
|---|
Unlock 67 industrial permits in New Hampshire
Search every industrial and commercial discharger in New Hampshire by name or permit number, with permit status, expiry and violation history. Free with a Klarifi account.
Industrial and commercial NPDES permits in New Hampshire: permits in force (effective or administratively continued) held by facilities EPA does not class as publicly owned treatment works or federal facilities. Source: EPA ICIS-NPDES via Klarifi, October 2026.
Violations at New Hampshire wastewater plants
41 of the 47 municipal plants on this page recorded at least one effluent violation, a monitored value above a permit limit, in the last three years, and 45 had a violation of any kind, including late or missing monitoring reports. Each plant’s page shows its own count. EPA’s enforcement records list 46 formal cases naming New Hampshire wastewater plants, 7 of them since fiscal year 2020, with $205,950 in penalties assessed. Enforcement cases in New Hampshire →
Permit renewals by year
An NPDES permit runs for five years. To keep discharging, a plant must apply for renewal at least 180 days before the expiry date, and the renewed permit usually arrives with tighter effluent limits, new monitoring requirements or a compliance schedule. That is why the year a permit expires is the year a plant starts budgeting for upgrades: nutrient removal, disinfection, capacity or controls.
Largest permit holders in New Hampshire
| Facility | City | Avg flow (MGD) | Design (MGD) | NPDES permit | Status | Expires | Violations (3y) |
|---|---|---|---|---|---|---|---|
| Nashua WWTP | Nashua | 9.77 | 16 | NH0100170 | Administratively continued | May 2020 | 76 |
| Wrbp Franklin Wastewater Treatment Plant | Franklin | 5.19 | 11.5 | NH0100960 | Effective | Jun 2029 | 24 |
| Concord Wastewater Treatment Facility | Concord | 3.5 | 10.1 | NH0100901 | Effective | Aug 2027 | 8 |
| Keene Wastewater Treatment Facility | Keene | 1.87 | 6 | NH0100790 | Effective | Nov 2026 | 8 |
| Rochester Wastewater Treatment Facility | Rochester | 2.88 | 5 | NH0100668 | Effective | Jun 2028 | 3 |
| Pierce Island Wastewater Treatment Plant | Portsmouth | 3.28 | 4.8 | NH0100234 | Effective | Nov 2028 | 47 |
| Huckleberry Hill Wastewater Treatment Facility | Dover | 2.18 | 4.7 | NHG58A003 | Expired | Jan 2026 | 30 |
| Leavitt E. Magrath Wastewater Treatment Facility | Hampton | 2.24 | 4.7 | NH0100625 | Expired | Feb 2026 | 29 |
| Derry, Town Of, Wastewater Treatment Plant | Derry | 1.46 | 4 | NH0100056 | Administratively continued | Feb 2016 | 16 |
| Claremont Wastewater Treatment Facility | Claremont | 1.39 | 3.9 | NH0101257 | Administratively continued | Sep 2021 | 0 |
New Hampshire NPDES permits: questions
NPDES permit search in other states
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 12, 2026.
Wastewater terms: NPDES permit · POTW · Significant industrial user · MGD · Biological nutrient removal · Tertiary treatment · all terms