Will a septic system work on this lot?
Enter an address. We check the USDA soil survey's septic rating, water table, bedrock, FEMA flood zone and nearby USGS wells, so you know what a perc test is likely to find before you buy the land.
Free. Uses USDA soil survey, FEMA flood maps and USGS well data. Full PDF report $19 one-time · free sample report
1. Soil rating
USDA NRCS rates every mapped soil for septic tank absorption fields: not limited, somewhat limited, or very limited, with the reasons.
2. Water, rock, flood
Seasonal water table and bedrock depth from the soil survey, plus the FEMA flood zone at the point.
3. Nearby wells
USGS groundwater wells within one mile, with well depth and the latest measured depth to water.
Full septic pre-check report
$19 one-time · PDF
Everything above plus plain-English explanations of each limiting feature, what the rating means for a conventional system vs. mound, ATU or drip systems, typical perc-test costs and exactly who to call, with sources and dates.
Common questions
What is a perc test?
A percolation (perc) test measures how fast water soaks into the soil where a septic drain field would go. A tester digs holes, pre-soaks them, and times how fast the water level drops, usually reported in minutes per inch. Many states now also require (or instead require) a soil profile evaluation, where a licensed evaluator inspects the soil layers for seasonal wetness and restrictive layers.
Sources: U.S. EPA - How Your Septic System Works; Fixr - Perc test cost (Jan 2025)
How much does a perc test cost?
Published U.S. ranges run roughly $600 to $1,900. HomeAdvisor reports most tests cost $750 to $1,900 (about $1,300 on average, with extremes of $300 to $3,000); Fixr reports $600 to $800 (about $725 on average). Price depends on the number and depth of test holes, your state's rules, and county permit fees.
Sources: HomeAdvisor - Perc test cost (Apr 2025); Fixr - Perc test cost (Jan 2025)
Is this site a perc test?
No. SepticSoil is a free pre-check from public records: the USDA soil survey's septic rating for the mapped soil at your address, FEMA's flood zone, and nearby USGS groundwater wells. It helps you decide whether a lot is worth testing. Only an on-site perc test or soil evaluation, reviewed by your county or local health department, decides what system a lot can have.
Sources: USDA NRCS - Soil Data Access; FEMA - National Flood Hazard Layer; USGS - Water Data for the Nation
What do 'not limited', 'somewhat limited' and 'very limited' mean?
They are the USDA NRCS ratings for 'Septic Tank Absorption Fields'. Not limited: the soil is very favorable. Somewhat limited: limitations can be overcome by special planning, design or installation. Very limited: limitations generally cannot be overcome without major soil reclamation, special design or expensive installation. The ratings consider depth to the water table and bedrock, flooding, slope, and how fast water moves through the soil.
Sources: USDA NRCS - Web Soil Survey