Septic soil in Lamb County, TX, by the numbers

Somewhat limited

Soil across 73.3% of Lamb County, TX rates "Somewhat limited" in USDA's septic-absorption-field interpretation. That's a middle reading: not the outright failure "very limited" soil produces, but not a clean pass either. Design changes often bridge the gap. Lamb County covers 1,016.181 square miles and counts 12,687 residents.

This is a county figure, not a parcel figure

Two lots a mile apart in Lamb County can carry different soil, even though they share one countywide rating. A site-specific perc test, usually $750-$1,850, is what a health department will actually require before permitting a lot in Lamb County.

System cost, conventional vs. engineered

Given Lamb County's rating, plan for the engineered-system range rather than the conventional one. The engineered-system range, $10,000-$40,000 (mound or aerobic treatment), is the more realistic number to plan around, against $3,000-$8,000 for a conventional system on the rare lot that passes.

Where this sits nationally

Nationally, Lamb County, TX is the 3,027-most-constrained of 3,058 rated counties for septic soil. Within Texas alone it ranks 244 of 253.

Before you act on this

How this rating is built, and its real limits · How a percolation test actually works