The following is a map unit description from the "Soil Survey of Norfolk and Suffolk Counties, Massachusetts (Peragallo, 1989)"
RdA-Ridgebury fine sandy loam, 0 to 5 percent slopes. This is a very deep, nearly level and gently sloping, poorly drained soil in depressions and along drainageways, on uplands. Areas of the soil are irregular or long and narrow in shape and range from 6 to 20 acres.
Typically, the surface layer is very dark brown fine sandy loam about 10 inches thick. The subsoil is about 9 inches thick. It is dark brown fine sandy loam in the upper part and mottled, grayish brown fine sandy loam in the lower part. The substratum is very firm, mottled, light brownish gray fine sandy loam to a depth of 60 inches or more.
Included with this soil in mapping are small areas of Whitman soils in depressions and Scituate and Woodbridge soils on low knolls. Included areas make up about 15 percent of the map unit.
Permeability: Moderate or moderately rapid in the surface layer and the subsoil and slow or very slow in the substratum.
Available water capacity: Moderate.
Soil reaction: Very strongly acid to moderately acid throughout.
Depth to bedrock: More than 60 inches.
Depth to the seasonal high water table: 0 to 1.5 feet.
Hydrologic group: C.
Most areas of this soil are woodland. A few areas are pastureland.
This soil is suited to cultivated crops and pasture. The seasonal high water table is the main limitation. The dense, compact substratum limits installation of effective drainage systems.
Potential productivity for northern red oak on this soil is moderate. Management concerns are the seasonal high water table, high seedling mortality, and the hazard of windthrow. Low soil strength limits the use of equipment to periods when the soil is dry or frozen. Thinning the stands helps to minimize windthrow if residual stand density is at or slightly above standard stocking levels and if changes in stand density are limited to 30 percent or less.
Constructing buildings without basements, above the seasonal high water table, helps to prevent the damage to the interior by the seasonal high water table. Tile drains around foundations and the use of sump pumps in basements help to lower the seasonal high water table. Landscaping designed to drain surface water away from buildings also helps to prevent the damage to the interior by the seasonal high water table. Constructing roads on raised, coarse textured base material and providing adequate side ditches and culverts help to prevent the damage to roads by the seasonal high water table and potential frost action. The seasonal high water table and slow or very slow permeability are the main limitations of the soil to use as sites for septic tank absorption fields. Placing distribution lines in a mound of more suitable fill material helps to overcome these limitations.