Septic soil in Valencia County, NM, by the numbers

Very limited

Soil across 72.9% of Valencia County, NM rates "Very limited" in USDA's septic-absorption-field interpretation. 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. Valencia County, NM is 1,066.717 square miles with a population of 80,813.

What Valencia County's reading doesn't cover

Valencia County's rating is an average across the whole county, not a promise about any one lot inside it. A local percolation test, typically $750-$1,850 (around $1,300 typical), is the only way to know what one lot in Valencia County will actually do.

What a system would cost here

With 72.9% of Valencia County rating "Very limited", a standard gravity system is not a safe assumption here. 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 Valencia County, NM compares

Nationally, Valencia County, NM is the 2,374-most-constrained of 3,058 rated counties for septic soil. Within New Mexico alone it ranks 14 of 29.

Further reading

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