New Hampshire SWPPP inspection requirements

The short version
Rain trigger
0.25″ storm event
Post-rain deadline
Within 24 hours
Routine inspections
Every 7 or 14 days
Permit
2022 Construction General Permit (CGP), as modified 2025
Agency
U.S. EPA (federal program)

How New Hampshire handles construction stormwater

New Hampshire is one of the few jurisdictions where the U.S. EPA runs the NPDES construction stormwater program directly. Construction sites disturbing one acre or more operate under the federal Construction General Permit (CGP). New Hampshire has not been delegated NPDES construction stormwater authority, so EPA's federal CGP applies directly. Inspect every 7 days, or every 14 days plus within 24 hours of a storm of 0.25″ or more (snowmelt from 3.25″ of snow also triggers). If the rain falls on a non-work day, inspect on the next work day. The 2022 CGP (modified April 2025) expires February 16, 2027; EPA plans to propose the next CGP before then.

Inspector qualifications

A "qualified person" who has completed EPA's construction inspection training course and exam (or an equivalent training/certification program) per Part 6.3 of the CGP — required for projects covered on or after February 17, 2023.

Official sources

Common questions

What triggers a SWPPP inspection in New Hampshire?

Under the 2022 Construction General Permit (CGP), as modified 2025, a storm event of 0.25 inches or more triggers a post-storm inspection, within 24 hours (non-work days typically extend to the next work day; check your permit). Routine inspections: every 7 or 14 days.

Who can perform SWPPP inspections in New Hampshire?

A "qualified person" who has completed EPA's construction inspection training course and exam (or an equivalent training/certification program) per Part 6.3 of the CGP — required for projects covered on or after February 17, 2023.

Who administers the construction stormwater program in New Hampshire?

New Hampshire is not delegated NPDES construction stormwater authority, so the U.S. EPA administers the program directly under the federal Construction General Permit.

What are the penalties for SWPPP violations in New Hampshire?

Federal Clean Water Act civil penalties can reach $68,445 per day per violation, and EPA can issue administrative orders and state penalties on top. Missing rain-triggered inspections is among the most commonly cited violations in stormwater audits.

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