Over the coming months, the US Environmental Protection Agency (EPA) is to begin the process of developing a proposed standard for wastewater discharges produced by natural-gas extraction from underground coalbed and shale formations.
The agency announced on 20 October 2011 that a schedule for development of standards would lead to coalbed-gas wastewater standards in 2013 and shale-gas standards in 2014. No comprehensive set of US national standards exists at present for disposal of wastewater discharged from natural-gas extraction activities.
The EPA also said it would be looking in particular at the potential for cost-effective steps for pretreatment of this wastewater based on practices and technologies that are already available and being deployed or tested by industry to reduce pollutants in these discharges. Several companies in the desalination and water-reuse sector have taken an interest in developing technologies for dealing with produced water and other wastewater at coalbed and shale gas sites.
“The president has made clear that natural gas has a central role to play in our energy economy,” said EPA administrator Lisa P Jackson. “That is why we are taking steps — in coordination with our federal partners and informed by the input of industry experts, states and public health organizations — to make sure the needs of our energy future are met safely and responsibly.”
Recent technology and operational improvements in extracting natural gas resources, particularly shale gas, have increased gas drilling activities across the US. Production from shale formations has grown from a negligible amount just a few years ago to almost 15% of total US natural-gas production, and this share is expected to triple in the coming decades.
Currently, wastewater associated with US shale gas extraction is prohibited from being directly discharged to waterways and other waters. While some of the wastewater from shale gas extraction is reused or re-injected, a significant amount still requires disposal.
As a result, some shale gas wastewater is transported to treatment plants, many of which are not properly equipped to treat this type of wastewater. EPA will consider standards based on demonstrated, economically achievable technologies, for shale gas wastewater that must be met before going to a treatment facility.
Wastewater associated with coalbed methane extraction is not currently subject to national standards for being directly discharged into waterways and for pretreatment standards. Its regulation is left to individual states.
For coalbed methane, EPA will be considering uniform national standards based on economically achievable technologies. Information reviewed by EPA, including state-supplied wastewater sampling data, has documented elevated levels of pollutants entering surface waters as a result of inadequate treatment at facilities.
To ensure that these wastewaters receive proper treatment and can be properly handled by treatment plants, EPA will gather data, consult with stakeholders, including ongoing consultation with industry, and solicit public comment on a proposed rule for coalbed methane in 2013 and a proposed rule for shale gas in 2014.