St. Mathew Island Area, Alaska
The most common soil here is E39-Maritime dwarf scrub-gravelly colluvial slopes, on about 19% of the land. E39-Maritime scrub-sedge-gravelly frozen till slopes and E39-Maritime tussock-silty frozen slopes come next.
About 60% of the land drains well, and 38% stays wet for long stretches; groundwater comes within two feet of the surface under 98% of it.
USDA rates 98% of the land very limited for a standard septic drain field, and 98% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 14% of the land floods occasionally or more, and bedrock lies within 40 inches under 60% of it.
Soils change over short distances, so look up an address below for the soil at that exact spot and the reasons behind each rating.
The biggest mapped areas
The dominant drainage class is Well drained and the dominant hydrologic group is D (very slow infiltration, high runoff). The most common soil order is Gelisols — permafrost soils found in very cold climates. This report summarizes the major soil map units across the survey area to help you understand what to expect when buying, building, or gardening in St. Mathew Island Area, Alaska. Search your address to find the exact soil composition, drainage, and series details at your specific location.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Northern Bering Sea Islands-NorthMaritime Upland-Rounded Mountains | 49K | Well drained | D | Very limited | Very limited |
| Northern Bering Sea Islands-Maritime Upland-Plains | 20K | Very poorly drained | D | Very limited | Very limited |
| Northern Bering Sea Islands-Maritime Lowland-Coastal Plains | 12K | Very poorly drained | B/D | Very limited | Very limited |
| Northern Bering Sea Islands-Maritime Water, Saline | 2K | Not limited | Not limited |
Soil Orders in This Area
The USDA classifies every soil into one of 12 soil orders. Here are the dominant orders found in this survey area.
What This Means
Building & Foundations
About 98% of soils are rated "very limited" for dwellings with basements. Specific challenges include steep slopes, poor drainage in some areas, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 98% of soils are rated "very limited" for septic absorption fields. Despite good drainage overall, limitations may stem from shallow bedrock, steep slopes, or seasonal conditions. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.
Gardening & Agriculture
Drainage is generally favorable for gardening. Adding compost and mulch will improve fertility and water retention. Test your soil's pH before planting — most vegetables prefer 6.0-7.0.