Scientists with the US Geologic Survey are studying the relationship between earthquakes, gas drilling and the practice of re-injecting waste-water into the ground. They're looking at area around Trinidad in Southern Colorado, where the number of earthquakes has been growing. Trinidad currently averages about eight magnitude-3 earthquakes a year.
Geophysicist Justin Rubinstein with the USGS, says there appears to be a correlation to the waste water injection process, but adds it happens at only a handful of the 35,000 injection wells across the country.
"If we’re able to understand which wells are going to cause earthquakes and which are not, this is very useful for people in the oil industry such that they can develop safe injection practices."
Rubinstein says that of the 20 -30 wells in the Trinidad area, only a couple seem to be related to earthquakes.