Strafford County, NH: the USDA septic-suitability picture

Very limited

Strafford County, NH: USDA's soil survey calls 90.3% of the county "Very limited" for a septic leach field. Expect the ground itself to work against a plain gravity system; USDA's strictest bucket alone covers 90.3% of the county. The county spans 367.479 square miles, home to 134,202 people.

What this number does and doesn't tell you

USDA's survey covers the whole of Strafford County, NH at once, not any single address. Budget $750-$1,850 for a real perc test on any specific parcel - that's the only figure a permit application accepts.

Strafford County: conventional vs. engineered cost

90.3% of Strafford County carrying a "Very limited" reading changes the realistic budget here. Conventional systems run $3,000-$8,000 where they pass; where they don't, engineered alternatives (mound or aerobic treatment, whichever the health department requires) run $10,000-$40,000 - budget toward the higher figure until a perc test says otherwise.

Where this sits nationally

Among the 3,058 rated counties on this site, Strafford County, NH ranks 1,227 most-constrained nationally, and 2 of 10 within New Hampshire.

Further reading

How this rating is built, and its real limits · Conventional vs. engineered septic systems