Somervell County, TX: the USDA septic-suitability picture
Very limited
Somervell County, TX's SSURGO dominant class comes back "Very limited", covering 76.3% of the county. This is the reading that pushes a project toward an engineered system rather than a conventional one, and it covers 76.3% of Somervell County's land. The county spans 186.207 square miles, home to 10,098 people.
What this number does and doesn't tell you
Somervell 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.
Somervell County: conventional vs. engineered cost
76.3% of Somervell 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 Somervell County, TX compares
Among the 3,058 rated counties on this site, Somervell County, TX ranks 2,218 most-constrained nationally, and 167 of 253 within Texas.
Related guides
How this rating is built, and its real limits · Conventional vs. engineered septic systems