Underground Sources of Drinking Water (USDW)
Definition - What does Underground Sources of Drinking Water (USDW) mean?
Underground Sources of Drinking Water are aquifers that are formed in an underground layer of water-bearing permeable rocks by rainwater. The water seeps through porous soil, moves downward due to the force of gravity, and reaches a point where the rock bed and soul are saturated with water. It is stored under these permeable rocks and forms a source of underground water.
Petropedia explains Underground Sources of Drinking Water (USDW)
Underground water sources contain aquifers below the earth's surface which are capable of yielding a significant amount of water. There are two types of aquifers:
- Unconfined aquifers- These are aquifers allow water to seep in from the ground surface directly above the aquifer.
- Confined aquifers- These aquifers have an impermeable dirt/rock layer that prevents water from seeping into the aquifer from the ground surface located directly above.