On April 2, 2013, EPA Region 6 issued an Administrative Complaint (Complaint) under its authority pursuant to Section 309 of the Clean Water Act (CWA) to Linn Operating (Repsondent), Inc. located in Osage County, Oklahoma. The Complaint was issued in response to violation of Section 301 of the CWA for an unauthorized discharge of oil field brine and produced wastewater to a water of the U.S. The Complaint proposes a penalty. Respondent must respond to EPA Region 6 within thirty days of receiving the Complaint.