EPA Region 6 issued an Administrative Order (AO) under its authority pursuant to Section 309 of the Clean Water Act (CWA) to Polk Operating, LLC (Respondent) located in Ryan, Jefferson County, Oklahoma. The AO was issued for an unauthorized discharge of oil field brine and produced wastewater to waters of the U.S. The AO orders Respondent to: 1) Immediately cease all discharges of pollutants from the facility; 2) Remove all pollutants from the flow paths located between the points of discharge at and near the facility and the tributary of Red Creek and other downstream water bodies; and 3) And, remove sufficient amounts of pollutants from the tributary of Red Creek and other downstream water bodies, which were discharged from the facility on or about March 28, 2018, so that the TDS in downstream of the discharge is at or below background TDS. Respondent must respond to EPA within thirty days of receipt of the AO.