1) Water from a well is more likely to be clean to drink. Groundwater is purified as it percolates through some rocks and is not exposed to surface contamination as rivers are.
2) Overuse of groundwater is a big concern for a lot of reasons! Groundwater is our most significant source of freshwater, however it takes hundreds to thousands of years to replenish because of how slow water can move through most rock types in the subsurface. Overusing groudwater causes the water table to fall, which may cause the ground to sink, wells to run dry, etc.
3) Policies that aim to reduce our use of water may help to conserve water levels in lakes and aquifers. Think about ways you can use less water at home!