Other gaps have emerged between theories of how underground injection should work and how it actually does. (scientificamerican.com)
Scientists say that deep underground injection of wastewater from oil and gas operations is triggering the tremors by pushing critically stressed faults past the snapping point. (sciencemag.org)
«In 10 to 100 years we are going to find out that most of our groundwater is polluted,» said Mario Salazar, an engineer who worked for 25 years as a technical expert with the EPA's underground injection program in Washington. (scientificamerican.com)