Johnson County, TX: the USDA septic-suitability picture

Very limited

Johnson County, TX's SSURGO dominant class comes back "Very limited", covering 91.6% of the county. A standard gravity system routinely fails on ground like this; the same share of the county falls in USDA's worst absorption-field bucket outright. The county spans 725.062 square miles, home to 210,547 people.

What this number does and doesn't tell you

Johnson 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.

Johnson County: conventional vs. engineered cost

91.6% of Johnson 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.

Johnson County's rank among Texas counties

Among the 3,058 rated counties on this site, Johnson County, TX ranks 1,091 most-constrained nationally, and 77 of 253 within Texas.

Before you act on this

How this rating is built, and its real limits · Conventional vs. engineered septic systems