Venango County, PA: the USDA septic-suitability picture
Very limited
Venango County, PA's SSURGO dominant class comes back "Very limited", covering 98% of the county. Practically, that rules out a simple gravity system for most of the county - 98% of it sits in USDA's most-constrained bucket. The county spans 674.265 square miles, home to 49,476 people.
What this number does and doesn't tell you
This is a countywide, area-weighted figure across every soil survey map unit in Venango County, PA - never a reading for one specific parcel. Budget $750-$1,850 for a real perc test on any specific parcel - that's the only figure a permit application accepts.
Venango County: conventional vs. engineered cost
98% of Venango 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, Venango County, PA ranks 246 most-constrained nationally, and 7 of 66 within Pennsylvania.
Related guides
How this rating is built, and its real limits · Conventional vs. engineered septic systems