New EPA Rule Keeps Oil & Gas Wastewater out of Local Treatment Plants

If you like clean water, we’ve got good news. This week the EPA finalized an important Clean Water Act rule that cements commonsense protections for water resources. EPA’s new technology-based categorical pretreatment standard prevents unconventional oil and gas operators from delivering salty, toxic wastewater to publicly owned water treatment facilities — also known as POTWs. These facilities are designed to handle residential sewage, not industrial waste, and often are unable to treat the types of pollutants common in unconventional oil and gas wastewater.

Since 1979, the Clean Water Act has prohibited onshore oil and gas operators in the eastern U.S. from directly discharging oil and gas wastewater to surface waters, like streams and lakes. But until now, there were no rules that applied to the wastewater that is disposed of at separate treatment facilities, or “indirect discharges.”

The final POTW pretreatment rule is consistent with current industry practice, but this wasn’t always the case. Prior to 2011, oil and gas operators in Pennsylvania delivered wastewater to POTWs for treatment and disposal with terrible results. These POTWs struggled to treat unconventional oil and gas wastewater due to elevated levels of halides, heavy metals, organic compounds, radionuclides and salts. High and fluctuating TDS (salt) levels in wastewater interfered with the biological treatment processes reducing treatment efficiency. Bromides that went through POTW disinfection processes were transformed into toxic disinfection by-products and released into receiving waters.

In April, 2011, Pennsylvania’s Department of Environmental Protection asked operators to voluntarily stop wastewater deliveries to POTWs, and shortly after, EPA began gathering information about the indirect discharge to make this voluntary action mandatory. Research conducted during and after the period confirms that POTWs and unconventional oil and gas wastewater aren’t a good match.

While this rule is certainly a big step in the right direction, it doesn’t protect communities from other potentially harmful wastewater discharges.

• Wastewater from conventional and coalbed methane oil and gas drilling isn’t covered by this rule, even though operators use similar chemicals to develop and maintain those wells.
• Wastewater generated from onshore oil and gas operations in the western U.S. can still be released at the surface if regulators decide that the water is of “good enough” quality to be used for wildlife or livestock watering or other agricultural uses.
• Wastewater can still be indirectly discharged to privately owned or centralized wastewater treatment facilities (CWTs).

Onshore oil and gas operations generate about 800 billion gallons of water each year, creating an ongoing management and disposal challenge.  With POTWs rightly out of the picture, unconventional oil and gas operators are increasingly turning to CWTs and other management and disposal strategies. Whether these CWTs and alternatives are equipped to handle the pollutants in oil and gas wastewater will have a big impact on water quality and public health.

EPA is currently evaluating whether CWTs are able to safely treat and manage unconventional oil and gas wastewater. As we learned with POTWs in Pennsylvania, even treated wastewater from oil and gas operations might not be truly “clean.” The right treatment method, robust testing monitoring and testing, and a complete understanding of the pollutants in wastewater to begin with are critical to ensuring we don’t repeat the POTW experience.

Unfortunately when it comes to oil and gas wastewater, data about its pollutants, the success of treatment practices, and the potential toxicity of its constituents is non-existent at worst and shaky at best. EDF is working with other researchers across the country to begin narrowing these data gaps to ensure we stay vigilant in protecting one of our planet’s most precious resources.