Since the drilling boom took off in recent years, people in states such as Kansas, Oklahoma, Texas and Pennsylvania have associated hydraulic fracturing with earthquakes.

But it isn’t the drilling that’s causing the earthquakes; it’s how the wastewater is disposed of after drilling that causes earthquakes, Pittsburgh Post-Gazette PowerSource reports. When drilling waste is injected into disposal wells that are thousands of feet deep, fluid pressures can increase and faults can potentially move, causing earthquakes.

Now, scientists and state regulators in Kansas and Oklahoma have found that they can stop these earthquakes by limiting the amount of wastewater disposed of in certain areas.

Read more: Pittsburgh Post-Gazette PowerSource > States show they can sometimes stop earthquakes