Rains County, TX: the USDA septic-suitability picture
Very limited
Rains County, TX's SSURGO dominant class comes back "Very limited", covering 88.5% of the county. This is the reading that pushes a project toward an engineered system rather than a conventional one, and it covers 88.5% of Rains County's land. The county spans 229.492 square miles, home to 13,306 people.
What this number does and doesn't tell you
Two lots a mile apart in Rains 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.
Rains County: conventional vs. engineered cost
88.5% of Rains 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 Rains County, TX compares
Among the 3,058 rated counties on this site, Rains County, TX ranks 1,423 most-constrained nationally, and 106 of 253 within Texas.
Further reading
How this rating is built, and its real limits · Conventional vs. engineered septic systems