The following is a map unit description from the "Soil Survey of Norfolk and Suffolk Counties, Massachusetts (Peragallo, 1989)"
WaA-Walpole sandy loam, 0 to 5 percent slopes. This is a very deep, nearly level, poorly drained soil in depressions and along drainageways of glacial outwash plains and terraces. Areas of the soil are narrow and irregular in shape and range from 6 to 40 acres.
Typically, the surface layer is very dark brown sandy loam about 9 inches thick. The subsoil is grayish brown sandy loam about 9 inches thick. The substratum is yellowish brown and pale olive gravelly loamy sand to a depth of 60 inches or more. In many areas the surface layer and the subsoil are fine sandy loam, and in other areas the surface layer is less than 9 inches thick.
Included with this soil in mapping are small areas of Sudbury, Raynham, and Scarboro soils. Raynham soils are in positions on the landscape similar to those of the Walpole soil. Sudbury soils typically are in convex positions, and Scarboro soils are in lower positions on the landscape. A few areas have a hard, cemented layer 2 to 6 inches thick that restricts water movement and root penetration in the lower part of the subsoil. Included areas make up about 20 percent of the map unit.
Permeability: Moderately rapid in the surface layer and the subsoil and rapid or very rapid in the substratum.
Available water capacity: Low or 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 1.0 foot.
Hydrologic group: C.
Most areas of this soil are woodland or are abandoned, idle fields. A few areas are used for pasture.
This soil is fairly suited to cultivated crops and pasture. The seasonal high water table restricts the root zone and keeps the soil saturated through late spring. The main management concern is overgrazing. Restricted grazing during wet periods helps to maintain a good growth of forage plants. Drainage systems help to lower the seasonal high water table and increase the choice of crops.
Potential productivity for red maple 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, and designing landscaping to drain surface water away from buildings help to protect the interior from damage 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. Constructing roads on raised, coarse textured base material and providing adequate side ditches and culverts help to protect the pavement from damage by the seasonal high water table and potential frost action.
The seasonal high water table and rapid or very rapid permeability are the main limitations to use of the soil as sites for septic tank absorption fields. Because of rapid or very rapid permeability, the soil readily absorbs but does not adequately filter the effluent. Consequently, ground water pollution is a hazard. Placing distribution lines in a mound of more suitable fill material helps to overcome these limitations.