New Hampshire Grease Trap Regulations
FOG Compliance Overview
New Hampshire follows the International Plumbing Code (IPC) as its base plumbing code. The IPC requires grease interceptors for food service establishments and references sizing based on fixture unit counts and flow rates. The state's regulatory authority is the New Hampshire Department of Environmental Services (DES).
With approximately 3,324 food service establishments statewide, New Hampshire has significant FOG compliance needs. Individual cities and municipalities may adopt additional local ordinances that go beyond the state plumbing code, including stricter pumping schedules, permit requirements, and enforcement penalties. Of the 2 cities we cover, 1 require a dedicated FOG permit. 1 city enforces the 25% rule for grease trap pumping.
Need a grease trap in New Hampshire?
Our free calculator uses IPC code requirements to recommend the right size for your establishment.
Size My Grease TrapCity Regulations in New Hampshire
| City | Pumping Frequency | Permit | 25% Rule |
|---|---|---|---|
| Concord | See details | — | — |
| Portsmouth | Monthly (standard); annually for some exempted establis... | Required | Yes |
Frequently Asked Questions
What plumbing code does New Hampshire follow for grease traps?
New Hampshire follows the International Plumbing Code (IPC). The IPC requires grease interceptors for food service establishments and sizes them based on fixture unit counts and flow rates. Individual cities may adopt stricter local ordinances.
How many food service establishments are in New Hampshire?
New Hampshire has approximately 3,324 food service establishments according to Census Bureau County Business Patterns data. We currently cover detailed FOG regulations for 2 cities in the state.
Do I need a grease trap permit in New Hampshire?
Permit requirements vary by city. Of the 2 cities we cover in New Hampshire, 1 require a dedicated FOG permit. Check your specific city's requirements below or contact your local wastewater authority.
What size grease trap do I need in New Hampshire?
Grease trap sizing in New Hampshire depends on your establishment's flow rate, number of fixtures, and local code requirements under the IPC. Use our free sizing calculator for a recommendation tailored to your setup.
Regulations change frequently. Always verify current requirements with your local wastewater authority or plumbing inspector before making compliance decisions. Last updated: March 2026.