Mary Ellen Ternes

Mary Ellen Ternes

Partner
Earth & Water Law, LLC

Mary Ellen Ternes is a partner in the Oklahoma City office of D.C. based Earth & Water Law, LLC.  Ms. Ternes represents energy, manufacturing and other industrial and municipal clients, with in-depth experience in air, hazardous waste, wastewater, drinking water program permitting, compliance, with particular emphasis in developing efficient regulatory strategies for complex and high profile processes and industries, enforcement defense, risk management, due diligence, voluntary cleanup practices as well as federal and state rulemaking, administrative proceedings and litigation.

Her relevant experience includes:

  • Representing an oil and gas producer in acquisition and implementation of CCUS;
  • Defending CCUS implementation against delegated state enforcement actions, including Clean Air Act compliance;
  • Defending oil and gas production industry in induced seismicity litigation, including a RCRA citizen suit;
  • Defending oil and gas services sector in UIC Class II waste injection related state and federal enforcement actions;
  • Negotiating one of the first major GHG air permit determinations requiring GHG Best Available Control Technology (BACT);
  • Representing a utility in a complex CAA permit dispute to resolve delegated authority and federal oversight issues;
  • Representing a manufacturing facility in power purchase agreement negotiations;
  • Representing energy sector clients in complex transactions, due diligence and compliance demonstrations;
  • Representing energy sector clients in EPA regulatory oversight and Requests for Information in developing regulations and pursuing enforcement initiatives.

Ternes began her career as a chemical engineer for the U.S. EPA Region 6 in Superfund emergency response and RCRA hazardous waste incinerator permitting, then left EPA to join industry, managing environmental compliance for a commercial hazardous waste incineration company, negotiating air, hazardous waste, and toxic substances treatment and disposal permits, demonstrating compliance and conducting audits. During law school, she was a law clerk for the U.S. EPA Office of General Counsel Air and Radiation Division.

Ternes currently serves as Secretary of the American College of Environmental Lawyers, Chair of the American Institute of Chemical Engineers Public Affairs and Information Committee Climate Change Task Force, and Chair-elect of the American Bar Association Business Law Section Environmental Committee.  Ternes founded AIChE’s Chemical Engineering and the Law Forum, and served as chair of the ABA’s Section of Environment, Energy and Resources Air Quality, and the Climate Change, Sustainable Development and Ecosystems Committees.   Ternes is a frequent speaker and author, contributing to the ABA’s Clean Air Act Handbook (Chapter 6: New Source Review, 2d, 3d and 4th ed.); CRC’s Air Pollution Control Handbook (2d ed.).  She is listed in Chambers USA Guide to America’s Leading Lawyers for Business; The Best Lawyers in America©, Oklahoma Super Lawyers and the International Who's Who of Environment Lawyers.

Ternes received her J.D. (high honors) from the University of Arkansas at Little Rock (1995) and her B.E. (ChE) from Vanderbilt University (1984). Ternes is admitted to practice law in Oklahoma, Arkansas, South Carolina, District of Columbia.