Immediately below the water table is the:

• A. Saturated zone
• B. Unsaturated zone
• C. Aquifer cap
• D. Aquifer recharge area

Answer: (A)

The saturated zone is the area immediately below the water table where all the pore spaces in the soil and rock are filled with water. In this zone, the groundwater pressure is at its maximum, and it is not influenced by atmospheric pressure. The water table itself represents the upper boundary of the saturated zone, marking the transition from unsaturated soil or rock above it, where some air fills the spaces between soil particles, to the saturated conditions below.

Understanding this distinction is key in the field of hydrology and water treatment, especially when it comes to groundwater management and aquifer studies. The saturated zone is crucial as it holds the groundwater that may be extracted for various uses, including drinking water supply and irrigation. Identifying the groundwater zones helps in planning for water resource management and understanding the behavior of contaminants in the subsurface environment.