What can humans do to improve the conditions of groundwater aquifers?
Minimize pollution and uncover upper parts with lots of cement/asphalt
Infiltration and percolation are sources of groundwater. If you minimize these processes by a lot of urbanization (paving, asphalting, heavy construction, cementing, etc.), groundwater aquifers will be in trouble in terms of their feeding. You have to know your safe withdrawal.
The other issue is contamination of groundwater from industrial, agricultural and domestic (such as septic tanks) sources. Fuel stations (gas stations) are one source. Underground storage tanks, if managed unproperly, might leak. Many examples can be given.
Another issue is salt application to deice roads in winter time. This cause groundwater pollution.