LOCATION WAIPAHU HIEstablished Series
TAXONOMIC CLASS: Fine, mixed, active, isohyperthermic Torrertic Haplustolls
TYPICAL PEDON: Waipahu silty clay - irrigated sugarcane. (Colors are for moist soil unless otherwise noted. All textures are "apparent field textures.")
Ap--0 to 12 inches; dark grayish brown (10YR 4/2) silty clay, dark brown (10YR 4/3) dry; moderate fine and very fine granular and moderate medium subangular blocky structure; very hard, friable, sticky and plastic; many roots; common fine and very fine pores; few coral fragments; violent effervescence with hydrogen peroxide; slightly acid (pH 6.5); clear smooth boundary. (8 to 12 inches thick)
B21--12 to 26 inches; dark brown (10YR 4/3) silty clay, dark yellowish brown (10YR 4/4) dry; strong very coarse prismatic structure parting to moderate medium and coarse subangular blocky; hard, firm, sticky and plastic; few coarse roots, many fine roots; few coarse, common fine and very fine tubular pores; many weak pressure faces; few coatings in pores; few fine black concretions; strong effervescence with hydrogen peroxide; slightly acid (pH 6.5); gradual wavy boundary. (10 to 14 inches thick)
B22--26 to 36 inches; dark brown (10YR 4/3) silty clay, dark yellowish brown (10YR 4/4) dry; strong very coarse prismatic structure parting to moderate medium and coarse subangular and angular blocky; hard, firm, sticky and plastic; few coarse roots, many fine roots; few coarse, common fine and very fine tubular pores; many weak pressure faces; few coatings in pores; few fine gradual wavy boundary. (10 to 14 inches
B23--36 to 46 inches; dark brown (10YR 4/3) silty clay, dark yellowish brown (10YR 4/4) dry; strong coarse prismatic structure parting to moderate medium and coarse subangular and angular blocky; common, deeply grooved slickensides oriented at 20 degrees; hard, firm, sticky and plastic; few coarse roots, common fine roots, mainly matted between prisms; few coarse pores, many very fine tubular pores; black stains in pores and on faces of peds; common pressure faces on peds; strong effervescence with hydrogen peroxide; slightly acid (pH 6.4); gradual smooth boundary. (8 to 12 inches thick)
B24--46 to 70 inches; dark brown (10YR 4/3) silty clay, dark yellowish brown (10YR 4/4) dry; strong coarse prismatic structure parting to strong medium and coarse subangular blocky; common deeply grooved slickensides; very hard, firm, very sticky and very plastic; few fine roots; many very fine pores; coatings in pores; common pressure faces; many fine black concretions; prominent black stains; strong effervescence with hydrogen peroxide; slightly acid (pH 6.4).
TYPE LOCATION: Honolulu County, Hawaii; 1,000 feet west of Waipahu High School boundary and 600 feet south of Farrington Highway in an irrigated sugarcane field.
RANGE IN CHARACTERISTICS: Average annual soil temperature is about 75 degrees F. The clay fraction is a mixture of kaolinite and montmorillonite. The amount of montmorillonite increases as depth increases. The soil is dry in some horizons for more than 90 cumulative days in most years. The solum has hue of 10YR or 7.5YR.
Value of the A and B horizon is 2 through 4 moist, and value in the B horizon is 4 or 5 dry. Chroma in the A and B horizons is 2 or 3 moist and 3 through 5 dry.
COMPETING SERIES: These are the Honouliuli, Pamoa, Waialua, and Waihuna series. Honouliuli soils have clay texture and 5YR hue throughout. Pamoa soils have hue of 5YR or redder. Waialua soils have very sticky and very plastic control sections that are mottled in the lower part. Waihuna soils have isothermic temperature.
GEOGRAPHIC SETTING: Waipahu soils are on dissected terraces, adjacent to the ocean but well above the present drainages. Slope is 0 to 12 percent. Elevation is from near sea level to 125 feet. The soils formed in old alluvium washed from material from basic igneous rocks. Average annual rainfall is 25 to 35 inches. Mean annual temperature is about 75 degrees F., average January temperature is 71 degrees F., and average July temperature is 78 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ewa, Hanalei and Pearl Harbor soils and the competing Honouliuli and Waialua soils. Ewa soils have 5YR or redder hue throughout. Hanalei soils are poorly drained. Pearl Harbor soils are adjacent to the ocean and are very poorly drained.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate to moderately slow permeability.
USE AND VEGETATION: Mainly urban developments and small areas in irrigated sugarcane.
DISTRIBUTION AND EXTENT: In the Waipahu, Pearl Harbor and Waialua areas. The series is inextensive and comprises about 2,238 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Soil Survey, Territory of Hawaii, 1949.
OSED scanned by SSQA. Last revised by state on 3/78.