EPA: Oilfield pollution may significantly degrade Wind River

The federal Environmental Protection Agency has told Wyoming regulators that a draft permit to allow Aethon Energy to discharge polluted water into creeks above the Wind River may result in significant degradation to that protected waterway.

Wyoming’s Department of Environmental Quality used an un-vetted interim policy to determine acceptable effluent limits that would reach the Wind River, an EPA administrator wrote in 14 pages of comments (see below). The river is a Class I waterway protected by federal environmental laws and Wyoming’s draft permit may result in “significant” degradation, EPA Region 8 Water Division Director Darcy O’Connor wrote June 27.

Aethon also commented on the proposed Wyoming permit, saying it “adequately satisfies applicable regulations.” In a 14-page letter, Aethon’s regulatory manager Andrea Taylor wrote that the draft permit “is more protective and compliance requirements have been significantly increased compared to previous permit authorizations for these discharges…(see below).”

But the federal agency saw seven major problems with Wyoming’s proposed permit for Aethon Energy. Atheon is seeking to renew and change a DEQ permit to allow it to discharge up to 2,161 tons a month of total dissolved solids at a rate of 8.27 million gallons a day from its operations in the Moneta Divide oil and gas field. The pollutants would flow into creeks above Boysen Reservoir, which discharges into the Wind River.

Aetheon and Burlington Resources are pursuing separate approval from the U.S. Bureau of Land Management to expand the oil and gas field by 4,250 wells. Located between Shoshoni and Casper in Fremont and Natrona counties, the field today has some 800 wells.

In addition to pointing out what it sees as shortcomings in Wyoming’s draft permit, the federal agency said it would review the final permit once the state resolves all issues raised during a three-month comment period.

“WDEQ has received significant public comment on this permit through the public notice process…” O’Connor wrote. “As a result, the EPA is requesting that WDEQ transmit the final permit for our review,” in accordance with federal regulations, O’Connor wrote.

Wyoming must toe federal line

Wyoming exercises home rule that enables DEQ to enforce federal environmental regulations, provided the state adheres to or exceeds national standards. The arrangement allows the state to propose and adopt its own rules, regulations and permits, but with the U.S. EPA acting as a watchdog.

The state agency is reviewing the federal comments, DEQ spokesman Keith Guille wrote in an email Wednesday. “Once our review is complete, we will then put together responses and/or make any changes if necessary,” he wrote.

“As you can imagine, with over 450 comments collected, it’s going to take some time to conduct our review,” Guille wrote. “At this point, we do not have any date when this will be completed.”

In addition to its worries regarding Wind River water quality, the EPA outlined problems it saw in topics regarding effluent limits, anti-degradation reviews of Badwater Creek and Boysen Reservoir, discharge of drilling fluids, the classification of waterways and testing requirements, among other “factual errors and clarity issues.”

The public, plus state and federal agencies, are responding to a 637-page modeling report and 113-page application for a “produced water” discharge permit. Produced water is a byproduct of oil and gas production, tainted water that is separated from gas and oil and frequently re-injected deep into not potable aquifers.

Reinjection capacity is limited in the Moneta area. The DEQ permit would allow clearly defined amounts of pollutants to be discharged onto the landscape instead. Untreated produced water would be blended with produced water that has been cleaned up at an existing treatment plant or other similar facilities.

Wyoming regulators have said the proposed discharges “would be lost in the normal background fluctuation,” of existing water quality flowing from Boysen Reservoir.

But EPA found fault with the way the state came to that conclusion. The problem centers on Wyoming’s 2007 “Interim Policy on Establishing Effluent Limits for Permitted Point Source Discharges to Class 1 water Tributaries.”

“This policy is not included in the state’s publicly available Antidegradation Implementation Policy,” the EPA letter reads. “The EPA was unaware of it prior to the drafting of this permit, and, to the EPA’s knowledge, it has never been subject to public notice or review.”

The interim policy “appears to be inconsistent with the federal requirements and Wyoming’s antidegradation implementation policy reviewed by the EPA and the public…” the letter reads.

The state’s methodology “is authorizing a water quality change from historic conditions rather than preventing it,” the letter reads, and “establishes a new higher concentration average baseline condition [of pollutants] for the Wind River.”

“The increased loads and concentrations will result in an estimated 88% load increase in ch[l]oride in the Wind River,” the letter reads. “the proposed effluent limit results in degradation that could be considered significant,” the EPA wrote.

Fracking fluid

The draft permit covers produced water but “does not cover” other fluids, such as those used for fracking and other development activities, the EPA wrote. Produced water comes from the oil and gas pay zones and is vastly different from hydraulic fracturing fluids and other liquids used to develop and increase oil and gas flows.

As such, development and fracking or stimulating fluids are treated separately. Wyoming needs to clarify wording on how drilling fluids, acids, stimulation waters or other fluids would be addressed, EPA said.

Aethon reported stimulating 15 wells in 2016 and 2017 using a variety of chemicals, EPA said.

“Research has shown that produced water, like flowback water, contains additives used during stimulation and maintenance processes,” the EPA wrote. “The permit does not address whether segregation of the flowback is required.”

Because “numerous hazardous substances” will potentially be used, and “will be part of the regular produced water discharge,” the EPA wants better monitoring. Wyoming’s proposed use of Whole Effluent Toxicity testing “is not sufficient to comprehensively identify all potential toxic effects,” the EPA wrote.

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Aethon’s comments included a two-page letter with proposed corrections and clarification and several pages of tables documenting discharge tests.

“Responsible resource development can continue to coexist with carefully permitted authorizations that protect downstream designated uses,” the company wrote. “Aethon believes this draft permit has been structured with a thoughtful compliance and monitoring program that will achieve that balance.”