Look up your ZIP
What the results mean
Drainage class
How quickly water moves through the soil, from “excessively drained” (sand that never holds water) to “very poorly drained” (waterlogged much of the year). It drives yard wetness, foundation moisture, and how a lawn or garden will behave.
Hydric rating
Whether the area’s soils formed under wet conditions — one of the indicators used in wetland identification. “Partially” or “predominantly hydric” is a yellow flag for building and septic, not a legal wetland determination.
Septic suitability & limitations
The USDA’s rating for septic-tank absorption fields: Not limited, Somewhat limited, or Very limited. The listed limitations (e.g. “depth to saturated zone”) are the specific constraints behind the rating — the same things a county sanitarian will flag on your lot.
Farmland class
The USDA’s agricultural rating, from “prime farmland” down to “not prime farmland.” Relevant if you garden, keep livestock, or care about the land’s productive value; “if irrigated” means the rating assumes water is supplied.
Flooding & ponding frequency
How often the soil is expected to flood (water flowing over the surface) or pond (water standing in depressions). “Occasional” or worse means plan grading, gutters, and drainage before you plan landscaping.
Water-table depth
The minimum depth to the seasonal high water table — how close groundwater gets to the surface in the wettest part of the year. Shallow water tables (under about 2 feet) complicate septic systems, basements, and foundations.
SSURGO coverage
The share of your ZIP that actually has soil-survey data. Water bodies, urban fill, and unsurveyed areas have none — the lower the coverage, the more the verdict describes the area rather than any particular lot.
Frequently asked questions
Is this a perc test?
No. A perc (percolation) test measures how fast water drains out of a hole dug on your specific lot, and it is the test counties actually use for septic permits. This tool reads USDA soil-survey data for your whole ZIP — a screening aid that tells you what to expect, not a test result. Only an on-site evaluation by your county or a licensed professional counts for permits.
Why is my ZIP not covered?
This lookup covers 7,223 ZIPs across 8 states (AZ, CO, FL, GA, MO, NC, TN, TX). If your ZIP isn’t covered, it may be outside those states, a PO-box-only ZIP (which has no land area to survey), or on tribal/federal land with no completed soil survey. If yours is missing, join the waitlist and tell us your ZIP; uncovered ZIPs help us prioritize.
How current is the data?
SSURGO is the USDA NRCS FY2026 refresh. NRCS updates surveys on a rolling basis as new fieldwork comes in, and soil properties change very slowly, so a 2026 vintage stays relevant for years.
What does “Somewhat limited” mean for septic?
It’s the middle rung of the USDA’s three-step rating for septic-tank absorption fields: Not limited (fewest constraints), Somewhat limited (workable but expect design changes or extra cost), Very limited (severe constraints — conventional systems are often ruled out). The limitations listed next to the rating, such as “depth to saturated zone,” are the specific reasons. None of these is a permit decision; your county makes that call.
What is a hydric soil, and should I worry?
Hydric soils formed under wet conditions and are one indicator used in wetland identification. “Partially hydric” or “predominantly hydric” is a yellow flag for building and septic — expect extra scrutiny, possible wetland review, and higher costs. It is not a wetland delineation; only a formal delineation determines whether wetlands regulations apply to your lot.
Why does the coverage percentage matter?
SSURGO doesn’t cover every acre: water bodies, dense urban fill, and some unsurveyed areas have no soil data. The percentage tells you how much of your ZIP the verdict actually reflects. Below roughly 50%, treat the result as a rough sketch of the area, not a read on your lot.
Is a ZIP code the same area the soil survey uses?
Not exactly. Soil surveys map physical land; we match them to Census ZIP-code areas (ZCTAs), which approximate USPS ZIPs but can differ at the edges, and ZIP boundaries change over time. A result for your ZIP describes the area, never your specific parcel — another reason this is screening, not a site report.
Can I use this to decide whether to buy land?
Use it to decide what questions to ask, not to skip them. A “Very limited” septic rating is a strong signal to make any offer contingent on a real perc test and county pre-approval. A clean-looking result is not a green light — soil varies lot to lot, and only on-site work confirms your parcel.