The underground disposal of produced waters from oil and natural gas (O&G) operations has proven to be a safe and environmentally reliable means of managing this water. Currently, there are nearly 172,000 salt water disposal wells regulated by US Environmental Protection Agency (EPA) Class II Underground Injection Control (UIC) regulations. These wells serve a vital role by supporting the responsible and sustainable development of O&G resources. These O&G Class II UIC wells are a subset of the more than 800,000 permitted UIC wells nationwide which serve the needs of many different industries and governmental entities.

During the last few years, there has been an increase in earthquakes in the central United States, including areas where oil and natural gas operations and activity have experienced substantial growth. In response, state regulators have taken a range of actions to reduce potentially induced earthquakes. Industry, academia, and governmental entities have initiated research to better
understand the science and mechanisms associated with the observed events.

n 2014 and 2015, a major collaborative effort was undertaken by the StatesFirst Initiative of the Interstate Oil and Gas Compact Commission (IOGCC) and Groundwater Protection Council (GWPC) to investigate the issue. This effort brought together technical experts from multiple stakeholder groups to produce a summary of current knowledge for managing the potential risk and informing stakeholders, including the public and media. The effort culminated with the September 2015 publication “Potential Injection-Induced Seismicity Associated with Oil and Gas Operations.” The document addresses the technical and regulatory considerations associated with evaluation of and response to: i) potentially induced seismicity, ii) seismic monitoring systems, iii) information collection and sharing, and iv) use of ground motion metrics. It also summarizes the range of approaches that have been or are being used by state officials and regulators to manage and mitigate
the risks associated with seismicity that may be induced by disposal wells.

More to come.