Septic soil in Hidalgo County, TX, by the numbers

Somewhat limited

62.4% of Hidalgo County, TX's surveyed soil comes back "Somewhat limited" in USDA's own SSURGO data, the county's dominant condition for a septic absorption field. 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. Hidalgo County covers 1,571.217 square miles and counts 914,820 residents.

This is a county figure, not a parcel figure

Nothing about Hidalgo County, TX's SSURGO figure applies to a specific address - it's a county-wide average. A site-specific perc test, usually $750-$1,850, is what a health department will actually require before permitting a lot in Hidalgo County.

System cost, conventional vs. engineered

Given Hidalgo 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.

How Hidalgo County, TX compares

Nationally, Hidalgo County, TX is the 2,999-most-constrained of 3,058 rated counties for septic soil. Within Texas alone it ranks 241 of 253.

Further reading

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