Understanding Soil Formation and Water Yield

When we talk about groundwater, different types of soil and rock formations play distinct roles in how water is stored and moves. These formations determine how much water can be extracted, which is referred to as the yield. The question describes a specific type of soil formation where water can pass through it, but the amount of water that can be obtained from it (the yield) is very small or insignificant.

Types of Groundwater Formations

Let's look at the common terms used to classify these subsurface formations based on their ability to store and transmit water:

• Aquifer: This is a saturated formation of permeable material (like sand, gravel, or fractured rock) that can store and transmit significant quantities of water. Aquifers are valuable sources of groundwater as they provide a high yield.
• Aquifuge: This is an impermeable formation (like solid rock or dense clay) that neither contains nor transmits water. Water cannot pass through an aquifuge.
• Aquiclude: This is a formation that is saturated with water but is relatively impermeable. It can store a lot of water but does not transmit it easily at a rate sufficient to be used as a water supply. Water movement through an aquiclude is very slow. It might allow some leakage, but the yield is practically zero.
• Aquitard: This is a formation that is semi-permeable. It can store water and transmit some water, but the rate of transmission is much lower than an aquifer. It allows water to pass through, but slowly, and the yield from drilling directly into an aquitard is insignificant. Aquitards often lie between aquifers and can transmit water between them.

Identifying the Soil Formation with Insignificant Yield

The question specifies a soil formation where water can pass through, but it gives an "insignificant yield". Comparing this description to the definitions above:

• An aquifer provides significant yield.
• An aquifuge does not allow water to pass through.
• An aquiclude stores water but has practically zero yield and very slow transmission.
• An aquitard allows water to pass through slowly and provides insignificant yield.

The description "water to go through soil formation and because of which it gives insignificant yield" perfectly matches the definition of an aquitard.

Conclusion

Based on the ability of the soil formation to transmit water and the resulting yield, a formation that allows water to pass through but provides insignificant yield is termed an aquitard.