Rockdale County's SSURGO septic rating
Somewhat limited
Rockdale County, GA: USDA's soil survey calls 71.3% of the county "Somewhat limited" for a septic leach field. 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 129.819 square miles, home to 97,610 people.
What this number does and doesn't tell you
This is a countywide, area-weighted figure across every soil survey map unit in Rockdale County, GA - 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.
Rockdale County: conventional vs. engineered cost
71.3% of Rockdale 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, Rockdale County, GA ranks 3,033 most-constrained nationally, and 149 of 159 within Georgia.
Related guides
How this rating is built, and its real limits · How a percolation test actually works