Irwin County, GA Septic Rating
Irwin County, GA: the USDA septic-suitability picture
Very limited
Irwin County, GA: USDA's soil survey calls 88% of the county "Very limited" for a septic leach field. That reading means a conventional system is a poor bet here - it's already USDA's strictest "very limited" bucket, not a partial constraint. The county spans 354 square miles, home to 9,155 people.
What this number does and doesn't tell you
Irwin County's rating is an average across the whole county, not a promise about any one lot inside it. Budget $750-$1,850 for a real perc test on any specific parcel - that's the only figure a permit application accepts.
Irwin County: conventional vs. engineered cost
88% of Irwin 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, Irwin County, GA ranks 1,467 most-constrained nationally, and 36 of 159 within Georgia.
Related guides
How this rating is built, and its real limits · Conventional vs. engineered septic systems