Member Information

Mary Ellen
Mary Ellen Ternes
Mary Ellen

Earth & Water Law LLC

5030 N May Ave, No. 324
Oklahoma City, OK73112-6010

Mary Ellen Ternes is a partner at Earth and Water Law, LLC. After an initial career as a chemical engineer in environmental incident response and remediation, air and waste chemical process permitting and compliance, she became an environmental lawyer serving as strategic compliance and enforcement defense counsel in permitting, enforcement and other actions involving air and water pollution, drinking water safety, incident response, waste management and Superfund actions before state and federal agencies and courts, and where compliance and pollution issues arise in transactions and development. She can be reached at

Work Phone:
(405) 286-2042

EPA Region:
Region 6 – (AR, LA, NM, OK, and TX)
Year of induction:
Vanderbilt University, Bachelor of Engineering, Chemical Engineering (B.E., ChE), 1985; University of Arkansas at Little Rock School of Law, Juris Doctor (J.D.), 1995.
Arkansas, District of Columbia, Oklahoma, South Carolina
Court Admissions:
D.C. Court of Appeals; Tenth Circuit Court of Appeals; United States District Courts in Oklahoma and Arkansas; Supreme Courts of Oklahoma, Arkansas.
Professional Societies and Organizations:
ACOEL, American Institute of Chemical Engineers (AIChE Fellow), American Bar Association Arkansas, D.C., Oklahoma and South Carolina Bar Associations Vanderbilt University Chemical and Biochemical Engineering Department Member, External Advisory Committee.
Other Environmental Career Experience:
Mary Ellen began her career in 1985 as an EPA Superfund “On-Scene Coordinator” and chemical engineer in emergency response and immediate removal actions, then she wrote hazardous waste incinerators permits as an EPA combustion expert. In 1989, Mary Ellen joined industry as the compliance manager for a commercial hazardous waste incineration treatment and disposal company, chairing the Permitting Committee for the industry’s trade group, the Hazardous Waste Treatment Council.
Representative Publications:
Co-Author, Chapter 6, New Source Review, Clean Air Act Handbook (2nd, 3rd and 4th Editions), ABA Press; Co-Author, Chapters 9, 10 and 11, Environmental Aspects of Real Estate and Commercial Transactions (5th Edition), ABA Press (currently in page proof review); Co-Author, Air Pollution Control Technologies (2nd Edition), CRC Press.
Illustrative Projects:
My projects include developing application of administrative and environmental law in the context of complex chemical engineering principles and processes to achieve the most efficient and overall beneficial strategies for industrial, energy, commercial and municipal clients in CAA, RCRA, CERCLA, EPCRA, SDWA and CWA permitting and enforcement, remediation, transactions, litigation, strategic development issues, as well as monitoring and participating in rulemaking. Over the past several years have focused on polymer science and US and international plastic regulation over the polymer lifecycle. Specific illustrative projects include - Serving as Global Council for Science and Environment Delegate to United Nations negotiations regarding UNEA March 2, 2022 Resolution To End Plastic Pollution with an International Legally Binding Instrument by 2024 - Creating and leading French and United States Comparative Law On Plastic Pollution, presented at the GCSE and French Embassy International Summit on Plastic pollution, httpswww.gcseglobal.orginternational-summit-plastic-pollution - Urban redevelopment including hotels, apartments, entertainment venues and restaurants in downtown Oklahoma City. - Successful defense of oil and gas company against RCRA citizen suit alleging wastewater injection caused Oklahoma Earthquakes. - Successful resolution for manufacturing company against CAA citizen suit alleging facility emissions caused trespass, nuisance against adjacent landowner, allowing modification strategies minimizing overall regulatory enforcement risk profile. - Successful resolution of EPA CERCLA 24 hour reporting enforcement action alleging failure to report chemical release, demonstrating that heat loss of the chemical reduced viscosity such that chemical could not have volatilized at rate alleged by EPA, allowing retraction of claim. - Advise and counsel international airports operated by municipal airport trusts regarding regulatory compliance, remediation and contractual issues arising in their operation with carriers and vendors in the context of legacy onsite aerospace manufacturing.
Citations of Major Published Cases:
Sierra Club v. Chesapeake Operating, LLC, et al., 248 F. Supp. 3d 1194 (W.D. Okla. 2017); Karr v. Hefner, 475 F.3d 1192 (10th Cir. 2007).