The Environmental Protection Agency has told Oklahoma officials they aren’t doing enough to protect the state’s drinking water and citizens from strong earthquakes caused by wastewater injection, a letter obtained by The Frontier shows.

State officials responded, saying Gov. Mary Fallin had appointed a task force to study other ways to dispose of wastewater generated by oil and gas drilling and other responses were under consideration.

The letter from Ron Curry, administrator for the EPA’s Region 6, notes that Oklahoma has taken some measures to reduce injection of wastewater produced by oil and gas drilling but states additional measures should be taken.

“We believe further actions to address disposal well-related pressure buildup in the Arbuckle Formation are imperative to protect human health and to prevent contamination of underground sources of drinking water from induced earthquakes,” states Curry’s letter, dated Nov. 22.

The letter was sent to Oklahoma’s three corporation commissioners: Bob Anthony, Dana Murphy and Todd Hiett. A copy of the letter was also sent to Mike Teague, state secretary of energy and environment.

The letter takes on additional significance due to the pending appointment of Attorney General Scott Pruitt to lead the EPA. Pruitt’s nomination was confirmed 11-0 by the Senate’s Committee on Environment and Public Works on Thursday, despite a boycott by Democrats on the panel.

Pruitt would be in a position to alter the EPA’s request and position on induced seismicity in Oklahoma. Such an action would impact energy companies here that have partnered with Pruitt in lawsuits against the federal agency to roll back or halt environmental regulations.

Curry’s letter notes that although the number of earthquakes in Oklahoma may have dropped in 2016, the intensity has increased.

“Two significant earthquakes in November, one near Pawnee and another near Cushing, and two additional earthquakes just today, suggest that more needs to be done to address this issue. We recognize that the Oklahoma Geological Survey reports the total number of 2016 earthquakes appears to be dropping from last year’s activity, but we also see a continued and disturbing upward trend in event magnitudes.”

[Read The Frontier’s ongoing coverage of Oklahoma’s earthquake epidemic.]

The letter urges the state to investigate other ways to dispose of millions of barrels of toxic wastewater if additional measures including additional reductions of wastewater disposal are needed.

“Further actions to address disposal well-related pressure buildup in the Arbuckle Formation are imperative to protect human health and to prevent contamination of underground sources of drinking water from induced earthquakes,” Curry’s letter states.

“These further actions should include looking at reasonable strategies to treat such discharges so that, in the event additional moratoria are needed, treatment options would be available.”

The letter also notes research showing a potential risk to the Cushing oil storage facility. A 5.0 quake struck downtown Cushing on Nov. 6, despite previous actions by the state and EPA to reduce wastewater injection into an earthquake-prone geologic zone known as the Arbuckle Formation.

“The U.S. Department of Homeland Security (DHS) projects that a quake of magnitude 5.7 could significantly damage the oil storage tanks in Cushing. Furthermore, a study led by U.S. Geological Survey (USGS) seismologist Dr. Daniel McNamara concluded that in 2014, earthquakes increased stresses along two stretches of a fault beneath Cushing and could lead to higher magnitude events,” his letter states.

“As you fully recognize, a breach in the integrity of the Cushing pipelines and storage facilities could be catastrophic for both the environment and the national energy system given the more than 80 million barrels of crude oil storage capacity.”

In a response to the EPA sent Nov. 29, the OCC’s director of administration said the agency was committed to working with federal officials to addressed induced earthquakes.

“Governor Fallin has appointed a task force to look into alternative methods of handling produced water from oil and gas wells, and this agency awaits the task force findings with great anticipation,” states the letter from Tim Rhodes.

“While the Oklahoma Corporation Commission has limited permitting authority over such recycling facilities, it fully supports the effort to reduce the amount of wastewater that is being disposed into the Arbuckle formation. Thus far the Commissioners have received only one application for a recycling operation that involves OCC jurisdiction, and that has been approved on a provisional basis.”

Scott Poynter, an Arkansas-based attorney who has filed several lawsuits against energy companies over the earthquakes, said he was surprised to hear about the letter.

“We think it’s really significant. It’s right in line with what we have been saying, that we think they are reactive, they are not doing enough. We think they are doing what they can to appease industry.”

Poynter said if Pruitt is confirmed by the full Senate, “I think it probably gets kind of swept under the rug.”

Fallin’s task force on produced water is expected to finish a preliminary report on alternatives to wastewater injection later this month.