EPA Region 6 issued an Administrative Order (AO) under its authority pursuant to Section 309 of the Clean Water Act (CWA) to Chaparral Energy, LLC (Respondent) located in Healdton, Carter 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 path located between the point of discharge at and near the facility and the tributary of Caddo Creek and other downstream water bodies; and 3) And, remove sufficient amounts of pollutants from the tributary of Caddo Creek and other downstream water bodies, which were discharged from the facility on or about July 11, 2019, so that the Total Dissolved Solids (TDS) downstream of the discharge is at or below background TDS. Respondent must respond to EPA within thirty days of receipt of the AO.