$522,000

What you're looking at

The USDA Natural Resources Conservation Service (NRCS) maintains the Soil Survey Geographic Database (SSURGO), which divides the landscape into polygons of similar soils mapped from aerial photos and field samples. Every polygon carries published ratings for drainage, hydric (wetland) status, septic absorption, and dwelling suitability. We query SSURGO at this listing's centroid coordinates and surface the dominant soil component's ratings for that polygon.

What “Very limited” actually means

NRCS's septic absorption rating is a roll-up that considers slope, permeability, depth to a restrictive layer (bedrock, fragipan, permafrost), filter-strip thickness above the water table, and frost action. A parcel with well-drained, non-hydric topsoil can still earn “Very limited” because of slope >15%, a slow subsoil, or a shallow restrictive layer. The rating reflects survey-scale character — it is not a pass/fail prediction for any specific lot.

Who actually decides whether you can build a septic

In Alaska, on-site wastewater approval is made by Alaska DEC's On-site Wastewater Treatment Systems program (or the local borough's authority where one exists), based on a site-specific perc test and soils log performed at your intended drainfield location. Plenty of parcels rated “Very limited” in SSURGO still get approved with a backhoe-pit log and a conventional or mound system; SSURGO is the starting point, not the verdict.

Why scale matters

Alaska's soil surveys are mapped at 1:24,000 in populated areas and 1:63,360 (or coarser) elsewhere. At those scales, the smallest reliably delineated unit covers several acres — meaning a 1-acre to 5-acre parcel is rated by whichever component dominates the larger surrounding polygon, not by what's actually under your specific building site.

Sources

• NRCS — SSURGO database overview
• NRCS — Alaska published soil surveys
• Alaska DEC — On-site Wastewater Treatment Systems
• NRCS Soil Data Access — the API we query