District of Columbia Soil Surveys
District of Columbia has 1 USDA soil survey areas covering a wide range of landscapes and soil conditions. The most common soil order is Ultisols — strongly weathered soils with clay-enriched subsoils, common in warm humid climates, making up roughly 58% of surveyed soils. Entisols — young soils with little profile development, often on floodplains or steep slopes account for another 21%.
In terms of drainage, 77% of District of Columbia 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.
Soil Types
Ultisols
58% of surveyed soils
Strongly weathered clay soils of the Southeast. Acidic and naturally low in nutrients. Clay subsoil can slow drainage.
Entisols
21% of surveyed soils
Young soils with little development — found on floodplains, dunes, and steep slopes. Properties vary widely by setting.
Inceptisols
16% of surveyed soils
Young but developing soils found in mountains and river terraces. Variable properties — check drainage and bedrock depth.
Alfisols
2% of surveyed soils
Moderately weathered forest soils with clay-enriched subsoil. Productive for agriculture, generally good for building and septic.
Mollisols
1% of surveyed soils
Fertile grassland soils with thick, dark topsoil. Among the best for agriculture, building, and gardening.