Carroll County, NH: the USDA septic-suitability picture

Very limited

Carroll County, NH's SSURGO dominant class comes back "Very limited", covering 82.5% of the county. This is the reading that pushes a project toward an engineered system rather than a conventional one, and it covers 82.5% of Carroll County's land. The county spans 931.876 square miles, home to 52,580 people.

What this number does and doesn't tell you

Two lots a mile apart in Carroll County can carry different soil, even though they share one countywide rating. Budget $750-$1,850 for a real perc test on any specific parcel - that's the only figure a permit application accepts.

Carroll County: conventional vs. engineered cost

82.5% of Carroll 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.

How Carroll County, NH compares

Among the 3,058 rated counties on this site, Carroll County, NH ranks 1,889 most-constrained nationally, and 9 of 10 within New Hampshire.

Further reading

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