Wastewater injection is culprit for most quakes in southern Colorado and northern New Mexico

PUBLIC RELEASE DATE: 15-Sep-2014

Contact: Nan Broadbent
Seismological Society of America
Wastewater injection is culprit for most quakes in southern Colorado and northern New Mexico

SAN FRANCISCO – The deep injection of wastewater underground is responsible for the dramatic rise in the number of earthquakes in Colorado and New Mexico since 2001, according to a study to be published in the Bulletin of the Seismological Society of America (BSSA).

The Raton Basin, which stretches from southern Colorado into northern New Mexico, was seismically quiet until shortly after major fluid injection began in 1999. Since 2001, there have been 16 magnitude > 3.8 earthquakes (including M 5.0 and 5.3), compared to only one (M 4.0) the previous 30 years. The increase in earthquakes is limited to the area of industrial activity and within 5 kilometers (3.1 miles) of wastewater injection wells.

In 1994, energy companies began producing coal-bed methane in Colorado and expanded production to New Mexico in 1999. Along with the production of methane, there is the production of wastewater, which is injected underground in disposal wells and can raise the pore pressure in the surrounding area, inducing earthquakes. Several lines of evidence suggest the earthquakes in the area are directly related to the disposal of wastewater, a by-product of extracting methane, and not to hydraulic fracturing occurring in the area.

Beginning in 2001, the production of methane expanded, with the number of high-volume wastewater disposal wells increasing (21 presently in Colorado and 7 in New Mexico) along with the injection rate. Since mid-2000, the total injection rate across the basin has ranged from 1.5 to 3.6 million barrels per month.

•••••