Septic suitability in Orange County, NC
Somewhat limited
Orange County, NC's SSURGO dominant class comes back "Somewhat limited", covering 65% of the county. Modification usually rescues a conventional system at this rating - added fill or a larger field - rather than forcing a full engineered redesign. The county spans 397.591 square miles, home to 152,877 people.
What this number does and doesn't tell you
Nothing about Orange County, NC's SSURGO figure applies to a specific address - it's a county-wide average. Budget $750-$1,850 for a real perc test on any specific parcel - that's the only figure a permit application accepts.
Orange County: conventional vs. engineered cost
65% of Orange County carrying a "Somewhat 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, Orange County, NC ranks 2,994 most-constrained nationally, and 94 of 97 within North Carolina.
Further reading
How this rating is built, and its real limits · How a percolation test actually works