The following is a map unit description from the "Soil Survey of Norfolk and Suffolk Counties, Massachusetts (Peragallo, 1989)"
Rm-Rippowam silt loam. This is a very deep, nearly level, poorly drained soil on flood plains adjacent to streams and rivers. Areas of the soil are irregular in shape and range from 6 to 1 00 acres.
Typically, the surface layer is very dark grayish brown silt loam about 1 0 inches thick. The substratum is mottled and extends to a depth of 60 inches or more. It is brown fine sandy loam in the upper part and grayish brown, stratified medium and coarse sand in the lower part. In many areas the surface layer has less silt and more sand.
Included with this soil in mapping are small areas of Saco soils along the edges of streams. Also included are areas of soils that have more silt throughout than the Rippowam soil. Also included are areas of better drained soils in narrow bands in slightly higher, convex positions, Included areas make up about 20 percent of the map unit.
Pertmeability.- moderate or moderately rapid in the surface layer and the subsoil and rapid or very rapid in the substratum.
Available water capacity: Moderate.
Soil reaction: Strongly acid to slightly acid throughout.
Depth to bedrock.- More than 60 inches.
Depth to the seasonal high water table: 0 to 1.5 feet.
Hydrologic group: C.
Flooding: Frequent for brief periods.
Most areas of this soil are woodland or in marsh grasses and sedges.
This soil is suited to cultivated crops and pasture if it is drained. In undrained areas the soil is saturated by the seasonal high water table through late spring and is poorly suited to farming. The main conservation practices needed include installing field drains where feasible, proper timing of farming operations, planting water-tolerant plant species, and planting after spring flooding.
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.
This soil is generally not suitable to use as sites for buildings and septic tank absorption fields because of flooding and the seasonal high water table. Soils that are better suited to these uses are generally nearby. Constructing roads on raised, coarse textured fill material and providing adequate side ditches and culverts help to prevent the damage to pavement by flooding.
This soil is in capability subclass lVw.
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