PmD-Plymouth loamy coarse sand, 15 to 35 percent slopes. This very deep, moderately steep and steep, excessively drained soil is on hills and ridges in areas of ice-contact deposits and on moraines. It makes up about 0.5 percent (1,391 acres) of the survey area. It is mapped mainly in the Plymouth-Carver-Barnstable general soil map unit. Areas are irregular in shape and range from 5 to 150 acres in size.
Typically, the surface is covered with an organic layer. This layer is about 1 inch of loose, undecomposed pine needles, leaves, and twigs and 1 inch of partly decomposed and well decomposed organic material. The surface layer is about 3 inches thick. It is black, very friable loamy coarse sand in the upper 1 inch and gray, loose coarse sand in the lower 2 inches. The subsoil is about 26 inches thick. In sequence downward, it is 1 inch of dark brown, very friable gravelly loamy coarse sand; 5 inches of strong brown, very friable gravelly loamy coarse sand; 10 inches of yellowish brown, very friable gravelly loamy coarse sand; and 10 inches of light yellowish brown, loose gravelly coarse sand. The substratum extends to a depth of 65 inches or more. It is light brownish gray, loose gravelly coarse sand in the upper 12 inches and pale brown, loose coarse sand in the lower part.
Included with this soil in mapping are small areas of Barnstable, Carver, Hinckley, and Nantucket soils. Also included are areas where slopes are less than 15 percent and a few areas where stones are on the surface. Included soils make up about 35 percent of this unit.
Permeability is rapid in the subsoil of the Plymouth soil and very rapid in the substratum. Available water capacity is low. Depth to the seasonal high water table is more than 6 feet.
Most areas are used as woodland. Some areas have been developed for homesites.
This soil is suited to woodland. Droughtiness and the slope are limitations affecting woodland management. Operating equipment may be hazardous on the steeper slopes. Removal or control of competing vegetation helps to obtain the best growth of newly established seedlings. The most common trees are pitch pine, white oak, scarlet oak, eastern white pine, and black oak.
The slope is the main limitation if this soil is used as a site for buildings. Extensive land shaping is generally needed. Buildings and lots should be designed so that they conform to the natural slope of the land. Erosion is a severe hazard during and after construction. Planting well suited grasses as soon as possible after the surface is disturbed minimizes the erosion hazard.
This soil is poorly suited to septic tank absorption fields because of the slope and the rapid and very rapid permeability. The soil may not adequately filter the effluent. The poor filtering capacity may result in the pollution of ground water. The hazard of pollution increases with the density of housing. Installing the distribution lines on the contour or in areas that were graded during construction of the dwelling helps to overcome the slope. Precautionary measures may be necessary in some areas.