Phoenix's Toxic Plume Spreading
"This plume and others from industrial or commercial pollution across the Valley are generating special concern because an extended drought could make clean groundwater crucial to meeting future water needs, officials say... The contamination, which includes possibly cancer-causing chemicals in some areas, has forced the closure of dozens of wells across the Valley. Phoenix has closed 42 wells and mostly restricts its pumping to areas north of the Arizona Canal."
Thanks to Chris Steins