Septic soil in Howard County, MD, by the numbers
Very limited
Soil across 76.5% of Howard County, MD rates "Very limited" in USDA's septic-absorption-field interpretation. Expect the ground itself to work against a plain gravity system; USDA's strictest bucket alone covers 76.5% of the county. Howard County, MD is 250.95 square miles with a population of 339,668.
What Howard County's reading doesn't cover
Two lots a mile apart in Howard County can carry different soil, even though they share one countywide rating. A local percolation test, typically $750-$1,850 (around $1,300 typical), is the only way to know what one lot in Howard County will actually do.
What a system would cost here
With 76.5% of Howard 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 Howard County, MD compares
Nationally, Howard County, MD is the 2,202-most-constrained of 3,058 rated counties for septic soil. Within Maryland alone it ranks 13 of 23.
Related guides
How this rating is built, and its real limits · Conventional vs. engineered septic systems