Septic permit rules and requirements in New Hampshire
In New Hampshire, the state issues the septic permit itself. It comes from the Subsurface Systems Bureau, Water Division, New Hampshire Department of Environmental Services. The code is N.H. Code Admin. R. Env-Wq 1000. N.H. RSA 485-A:29 · checked 2026-09-12
Subsurface Systems Bureau
Writes the rules
checked 2026-09-23
The state
Issues the permit
checked 2026-09-12
N.H. Code Admin. R. Env-Wq 1000
Code section
checked 2026-09-23
Who issues a septic permit in New Hampshire
The state issues the permit itself, through the Subsurface Systems Bureau, Water Division, New Hampshire Department of Environmental Services.
The statute gives the department the sole power to approve a septic system. A town board may approve the subdivision plan, but not the septic system.
N.H. RSA 485-A:29 · checked 2026-09-12
Where the rule is written
The rules that govern every septic system in New Hampshire are N.H. Code Admin. R. Env-Wq 1000 — Subdivisions; Individual Sewage Disposal Systems. The state applies them directly.
It protects water supplies and stops pollution from septic systems across New Hampshire.
New Hampshire Code of Administrative Rules, Chapter Env-Wq 1000 · checked 2026-09-23
What state law requires
Does New Hampshire require a septic permit?
A septic system needs a permit to build, change, or replace it.
A same-size repair may use a simpler permit instead of full review.
New Hampshire Code of Administrative Rules, Chapter Env-Wq 1000 · checked 2026-09-23
Does New Hampshire require a percolation test?
New Hampshire requires a soil test pit and a percolation test before a permit.
The pit shows the soil. The test shows how fast water moves through it.
New Hampshire Code of Administrative Rules, Chapter Env-Wq 1000 · checked 2026-09-23
The minimum septic tank size New Hampshire allows.
1,250 gallons.
Applies to a house or senior home with four bedrooms or fewer.
A bigger home needs a bigger tank under the same rule.
New Hampshire Code of Administrative Rules, Chapter Env-Wq 1000 · checked 2026-09-23
How far a system must sit from a well in New Hampshire.
75 feet.
Applies to a system with a flow of 750 gallons a day or less, to a well.
A bigger system needs a wider radius under the same table.
New Hampshire Code of Administrative Rules, Chapter Env-Wq 1000 · checked 2026-09-23
How far a system must sit from the property line in New Hampshire.
10 feet.
Applies to a drainfield, called a bed in the rule, to a property line.
A tank needs less space under the same table.
New Hampshire Code of Administrative Rules, Chapter Env-Wq 1000 · checked 2026-09-23
Does New Hampshire require an inspection when a home is sold?
A buyer must get a septic check before closing on certain waterfront homes.
Applies to a home on the water, with part of the system within 250 feet of the shoreline.
The buyer may fix or swap the system instead of paying for a check.
N.H. RSA 485-A:39 · checked 2026-09-23
Must the installer be licensed in New Hampshire?
New Hampshire gives a permit to install a septic system after a test.
An owner may replace a system serving their own home without a permit.
N.H. RSA 485-A:36 · checked 2026-09-23
New Hampshire counties on this site
We have not published a New Hampshire county page yet. A county earns a page when we hold facts unique to it. Until then this page is the answer for every county in the state.
Telling us your county is how we decide which one to build next.
Sources
State records only. Each figure above has a government source and a checked-on date. County figures live on the county pages.
Verify before you act. Septic rules are set locally and they change. Check anything here with the Subsurface Systems Bureau before you spend money on it.