EPA requests additional information regarding Aethon permit

A formal letter from the Environmental Protection Agency (EPA) to the Wyoming Department of Environmental Quality (DEQ) may send Aethon Energy back to the drawing board with their proposed permit for the Moneta Divide field.

The EPA is a step above the DEQ in the chain of command so their requests for additional information and corrections will have to be adhered to. The requests could put off the permit for at least a year.

The EPA said the permit application lacks clarity as to how the technology-based effluent limits were developed and contains no analysis as to whether or not they comply with the federal effluent limitations guidelines.

The permit application must also include water quality based effluent limits for all pollutants and the EPA says it is unclear whether such an analysis was completed.

The EPA is asking for that analysis for pollutants used in all aspects of the drilling process and the degradation effects they may have for Alkali Creek, Badwater Creek and Boysen Reservoir.

The permit application cites a 2007 policy rather than the Antidegradation Implementation Policy previously reviewed by the EPA.

The EPA said they were not aware of the 2007 policy before the drafting of the permit and to their knowledge the policy has never been subject to public notice or review. Using the proper policy they believe the resulting effluent limits in the permit may result in degradation to water quality in the Wind River, which may not meet the State’s antidegradation rules for Class I waters.

“The permit authorizes the discharge of produced water from conventional oil and/or gas facilities to waters of the state if the effluent quality complies with effluent limits established by this permit,” the EPA states. Further, “this permit does not cover activities associated with discharges of drilling fluids, acids, stimulation waters or other fluids derived from drilling or completion of wells.”

In this instance, the EPA is asking for an explanation from Aethon how the fluids will be managed so they are not discharged.

The permit application also indicates they would like areas to be “grandfathered” in for chloride and total dissolved solids, in essence stating they believe these two items should not have to comply with current regulations.

In addition, they say the Wyoming Game and Fish Department “determined that discharge of produced water from all existing permitted oil production units in Wyoming enhances wildlife propagation and habitat.”

The EPA disagrees, however, and is asking for a copy of the signed statement from the Wyoming Game and Fish Department detailing the value of the discharge to fish or wildlife.

Detailed explanations on the 5.5 acre mixing zone are being required by the EPA as well. They want to know what factors the DEQ used in deciding this was a reasonable area for mixing and does it actually fit within the mixing zone policy that requires limiting mixing zones to instances in which there “is near instantaneous and complete mixing of the discharge with the receiving water at critical conditions.”

Badwater Creek is designated by the State as a Class 2AB cold-water fishery. The EPA is concerned the high temperatures of discharge from the Moneta Divide field could be harmful. By law, the temperature in Class 2AB cold-water fishery waters cannot be raised more than two-degrees.

Because of this, the EPA is requesting a temperature modeling be performed to estimate potential impacts and impairments.

“A separate confirmation was done for oil and grease showing that oil and grease concentrations downstream of the Boysen Dam are well below the 10 mg/L industry standard,” the permit application states.

However, the EPA points out there has been no such analysis or statements provided for Alkali Creek, Badwater Creek, or Boysen Reservoir.

“The discharge is not being permitted with a general permit, nor are its impacts temporary or short-term,” the EPA said. “The Wyoming DEQ either did not completer or did not document the load or concentration-based first step required for a Tier 2 antidegradation review of Badwater Creek and Boysen Reservoir.

“No quantitative analysis regarding the percent increase of existing total load nor percent change in assimilative capacity was provided for this waterbody (Badwater Creek).”

As far as Aethon’s statement that discharges from the field will not result in significant degradation of Boysen Reservoir, there is no supporting analysis included in the permit application and the EPA wants that analysis in black and white.

As for the Wind River, the EPA is concerned there will be degradation to the Class I waterway beyond its historic limits.

The EPA is also questioning activities associated with the discharge of drilling fluids, acids, stimulation waters or other fluids derived from drilling or completion of wells.

The permit application is vague at best on this issue, using the phrase “does not cover”, but the EPA points out Aethon reported 15 of their wells at the Moneta Divide field were stimulated from 2016-2017 using a variety of breakers, surfactants, gelling agents and demulsifiers.

Research has shown that produced water, like flowback water, contains additives used during stimulation and maintenance processes. The EPA is asking for clarification on how these chemicals are going to be handled.

There is also some question as to how testing and monitoring of the discharges is going to be done. Because hazardous materials will be used during the projected development of the field, including construction, production and reclamation operations, the EPA is questioning whether the annual Whole Effluent Toxicity (WET) testing is going to be enough.