Islands of Truk, Federated States of Micronesia
The most common soil here is Tolonier, on about 41% of the land: a very stony clay loam, firm and a little sticky. Dolen and Chia come next.
About 72% of the land drains well, and 23% stays wet for long stretches; groundwater comes within two feet of the surface under 23% of it.
USDA rates 95% of the land very limited for a standard septic drain field, and 85% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 23% of the land floods occasionally or more, and bedrock lies within 40 inches under 4% 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 Islands of Truk, Federated States of Micronesia, 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.
The biggest mapped areas
The dominant drainage class is Well drained and the dominant hydrologic group is A (high infiltration, low runoff). The most common soil order is Inceptisols — young soils with minimal horizon development but more than Entisols. 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 Islands of Truk, Federated States of Micronesia. 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 |
|---|---|---|---|---|---|
| Tolonier very stony silty clay loam, 30 to 50 percent slopes | 5K | Well drained | A | Very limited | Very limited |
| Chia mucky peat, 0 to 2 percent slopes, frequently flooded | 2K | Very poorly drained | A/D | Very limited | Very limited |
| Tolonier very stony silty clay loam, 50 to 75 percent slopes | 2K | Well drained | A | Very limited | Very limited |
| Tolonier very stony silty clay loam, 12 to 30 percent slopes | 2K | Well drained | A | Very limited | Very limited |
| Dolen silty clay loam, 12 to 30 percent slopes | 2K | Well drained | A | Very limited | Very limited |
| Rock outcrop-Rubble land complex, 0 to 99 percent slopes | 1K | Not rated | Not rated | ||
| Ngerungor mucky peat, 0 to 1 percent slopes, MLRA 195 | 1K | Very poorly drained | A/D | Very limited | Very limited |
| Dolen silty clay loam, 6 to 12 percent slopes | 1K | Well drained | A | Somewhat limited | Very limited |
| Typic Udorthents-Urban land complex, 0 to 1 percent slopes | 857 | Well drained | A | Not limited | Very limited |
| Dolen silty clay loam, 30 to 50 percent slopes | 850 | Well drained | A | Very limited | Very limited |
| Tolonier very stony silty clay loam, 6 to 12 percent slopes | 758 | Well drained | A | Very limited | Very limited |
| Dublon loamy fine sand, 0 to 2 percent slopes, occasionally flooded | 677 | Somewhat poorly drained | A | Very limited | Very limited |
| Ollei taxadjunct-Wahrekdam complex, 2 to 8 percent slopes | 440 | Well drained | D | Very limited | Very limited |
| Insak taxadjunct sandy peat, 0 to 2 percent slopes, frequently flooded | 380 | Very poorly drained | B/D | Very limited | Very limited |
| Dolen silty clay loam, 50 to 75 percent slopes | 148 | Well drained | A | Very limited | Very limited |
| Typic Tropohemists, 0 to 2 percent slopes, MLRA 195 | 30 | Very poorly drained | A/D | Very limited | Very limited |
| Water | 11 | D | Not rated | Not rated |
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 85% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, poor drainage in some areas, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 95% 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
Well-drained soils on sloped terrain — good for most plants but watch for erosion. Terracing, contour planting, and mulching help retain moisture and topsoil. Drip irrigation is more effective than sprinklers on slopes.