The City’s soil is divided into two orders by location, the soil of the lowland and the soil of the upland. The soil of lowland has five (5) physiography that includes the following: Active Tidal Flat , Former Tidal Flat, Beach Ridges, Intermediary Valleys and Broad Alluvial Plain.
The Active Tidal Flats dominated by the Pangasinan Hydrosol Series whose soil type is Hydrosol, is characterized by a greenish gray to dark green surface as seen in wetlands and mudflats, suited for brackish fishpond culture.
Former Tidal Flat is covered with Pangasinan Series and divided by two soil types, the Pangasinan Fine Sandy Loam and Pangasinan Clay Loam, characterized by black to dark grayish surface moderately suited for rice production.
Beach Ridges is covered with Pangasinan Series whose soil type is Pangasinan Fine Sandy Loam, characterized by very dark brown structure-less surface suited for shrubs and coconut propagation.
Intermediary Valleys is mostly covered with Bani Series, visibly characterized by a dark gray to muddy and coarse granular clay, its soil type is Bani Silty Clay Loam. During dry season, the soil surface cracks to a depth up to 50 centimeters, lime precipitation in various forms are abundant in lower subsoil, but during wet season this soil is suited for rice production.
The Broad Alluvial Plain is covered largely by Alaminos Series, visually characterized by a reddish brown to granular loam which has a depth of about 44 centimeter in the lower horizon. There are two soil types that spreads over these areas , the Alaminos Silt Loam and Alaminos Silty, both are suitable for rice production.
Soils of the upland on the other hand has three physiography which include the following to wit: Low Sedimentary Hills( characterized by slightly dissected to slightly undulating to sloping low sedimentary hills with occasional narrow valleys), Rugged Limestone Hills and Low Volcanic Hills( characterized by slightly undulating to sloping; volcanic foot slope and slightly to moderately dissected low volcanic hills).
The Low Sedimentary Hills is covered with Bani Series with soil type Bani Clay Loam, surface are brown to dark brown, silty clay loam in texture, suited for shrubs, grass and fruit trees. On the other hand, the Rugged Limestone Hills is dominated with Bolinao Series and its noted soil type is Bolinao Clay Loam degraded phase, suited for grass, shrubs and few selected fruit trees. The Low Volcanic Hills is mostly covered with Alaminos Series with a soil type known as Alaminos Clay Loam, it is noted that these area is suited for agro-forestry. (Different Soil Types, Soil Type Distribution by Barangay)