At a glance
| Who regulates | NH Department of Environmental Services (NHDES) Subsurface Bureau and the local health officer |
|---|---|
| Inspection when a home is sold | Required in some areas. Required for developed waterfront property where the septic system is within 250 feet of the reference line. The buyer arranges it, or accepts the seller's report if it is no more than 180 days old. |
Who the waterfront law covers
- Any developed property where part of the septic system is within 250 feet of the reference line: the high-water mark of a lake or pond over 10 acres, coastal waters, or a fourth-order or larger river.
- The seller no longer has to do a site assessment; the seller should allow the buyer's inspection.
What the buyer must do
- Hire a New Hampshire licensed septic system evaluator before the transfer, or accept the seller's inspection report if it was done within the past 180 days.
- If the system was never approved by NHDES or was approved before September 1989, also hire a permitted septic system designer to check the disposal area's height above the seasonal high water table.
- The findings don't stop the sale, but a failed system must be repaired or replaced within 180 days after the transfer. Buyer and seller decide who pays.
Septic tank size in New Hampshire
Systems are designed by a New Hampshire permitted septic system designer and approved by the NHDES Subsurface Bureau.
Compare with other states on our tank size calculator.
Costs
We don't yet have checked New Hampshire-specific prices. National figures: pumping averages about $420–$430 (pumping cost), inspections about $550 on average (inspection cost), and a conventional system $3,000–$8,500 installed (installation cost).
Rules change, and counties and towns can be stricter than the state. Confirm with the agency above before you buy, sell or build.