The water table and the zone of saturation

1 What is the difference between the water table and the zone of saturation? 2 What is (are) the source(s) of pollution which causes eutrophication? 3 What causes a cone of depression? 4 What causes subsidence (collapsing aquifer)? 5 When road grime (oil, gasoline, coolant, etc) washes into storm drains and eventually creeks and rivers, is this point source or non-point source pollution? 6 When potential evaporation is much higher than precipitation in an area (such as a hot dry desert) what are the ways that humans can increase their supply of water for agriculture, industry, home use, etc? 7 What makes ground water mining different from just normal use of wells and groundwater?