American Samoa Soil Surveys
The most common soil here is Fagasa family, on about 21% of the land. Aua and Olotania family come next.
About 95% of the land drains well, and 2% stays wet for long stretches.
USDA rates 97% of the land very limited for a standard septic drain field, and 94% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 3% of the land floods occasionally or more, and bedrock lies within 40 inches under 85% 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 soils you're most likely standing on
The biggest named soils in American Samoa, each drawn five feet deep from its official USDA description, in its recorded colors.
Dots mark gravel; white flecks mark lime. Shares are by acres across the survey area, and each mapped patch usually mixes several of these soils.
American Samoa has 1 USDA soil survey areas covering a wide range of landscapes and soil conditions. The most common soil order is Mollisols — grassland soils with a thick, dark, fertile topsoil rich in organic matter, making up roughly 39% of surveyed soils. Andisols — soils formed in volcanic ash, very light and porous account for another 38%.
In terms of drainage, 96% of American Samoa soils are classified as well drained. Drainage class affects everything from septic system design to basement feasibility to garden planning. Use the survey area pages below to see drainage details for specific counties, or look up any address for an exact soil profile.