GEOS 1004 Lecture Notes - Lecture 10: Volcanic Ash, Vise, Bentonite
Document Summary
All water wells drilled from the earth"s surface into aquifers bypass _________________________ of groundwater infiltration and recharge. Wells provide a way to ____________________ material, whether beneficial or harmful, into aquifers very quickly. Old water wells must be abandoned by filling the well bore with sand at the depth where water can enter, followed by filling the rest of the well with sand, concrete, bentonite clay combo (mostly finish with concrete). Sinkholes developed in _________________________ bedrock, which is slowly dissolved by infiltrating precipitation, represent a natural way to rapidly introduce surface contaminants into groundwater. ______________________ streams typically only occur in limestone or dolomite landscapes, and may be a health hazard when water wells drilled into the subsurface reach the sunken stream instead of a slowly-recharged aquifer. Sunken streams can re-emerge at the land surface and appear to be springs, but they don"t actually represent where the _____________________ meets the land surface.
