Groundwater supplies can be easily contaminated by surface mining of coal All BUT ONE may be how surface mining might
adversely affect groundwater conditions,

A)
direct dumping of tailings and effluents into rivers

B)water used in the chemical extraction of metals, commonly contains
process chemicals

C)water which has trickled through solid mine wastes may contain dissolved
minerals, process chemicals, and/or metals


D)technologies used to control water flow prevents contamination