Areas of Expertise:

Biofuels, Carbon Capture and Sequestration, Clean Energy, Climate Change, Coal, Environment, Environmental Policy, GHGs, Natural Gas, Oil, Power Sector, Regulation, Renewables, Transportation, Water

Additional Areas of Expertise:

Federal rulemaking, appellate litigation, administrative law

Thomas Lorenzen is a partner in Dorsey’s Washington, D.C., office and a member of Dorsey’s Regulatory Affairs Group. Mr. Lorenzen’s practice focuses on environmental law and the federal rulemaking process. He represents clients in EPA rulemakings and in the development of federal environmental policy, as well as in environmental compliance counseling, due diligence and other transactional work, and in trial and appellate litigation, administrative actions, enforcement proceedings and complex negotiations relating to environmental review, major facility permitting, air and water quality, hazardous and solid waste and environmental cleanup.

From 2004 until joining Dorsey in 2013, Mr. Lorenzen was an Assistant Chief in the U.S. Department of Justice’s Environment and Natural Resources Division (ENRD). During that time, he supervised the federal government’s legal defense of all Environmental Protection Agency rules, regulations and other final actions judicially reviewable under the various federal pollution control statutes, including those involving the regulation of greenhouse gases under the Clean Air Act. Over his 16-year career at the Justice Department, Mr. Lorenzen managed or personally litigated dozens of seminal environmental cases under the Clean Air Act, Clean Water Act, Safe Drinking Water Act, Federal Food, Drug and Cosmetic Act, and other federal pollution control statutes. Notable cases for which he was responsible include:
• Massachusetts v. EPA (in which the U.S. Supreme Court confirmed EPA’s authority and duty to regulate greenhouse gases as pollutants under the Clean Air Act)
• Coalition for Responsible Regulation v. EPA (in which the D.C. Circuit upheld EPA’s first suite of substantive greenhouse gas regulations – the GHG Endangerment Finding, Light Duty Motor Vehicle GHG Rule, GHG Timing Decision, and PSD/Title V Tailoring Rule (presently under review by the Supreme Court))
• EME Homer City Generation L.P. v. EPA (in which the D.C. Circuit invalidated EPA’s Cross-state Air Pollution Rule (recently reversed by the Supreme Court))
• State of Mississippi v. EPA (in which the D.C. Circuit upheld EPA’s 2008 national ambient air quality standards for ozone)
• New Jersey v. EPA (in which the D.C. Circuit reviewed EPA’s Clean Air Mercury Rule)
• Portland Cement Ass’n v. EPA, Sierra Club v. EPA, and Natural Resources Defense Council v. EPA (in which the D.C. Circuit reviewed various EPA regulations governing emissions of hazardous air pollutants from stationary sources)
• New York v. EPA I & II (in which the D.C. Circuit reviewed two sets of regulations attempting to reform and streamline the Clean Air Act’s New Source Review program)
• Entergy Corp. v. Riverkeeper (in which the U.S. Supreme Court affirmed the EPA’s authority to weigh costs against benefits in determining how to regulate cooling water intake structures under the Clean Water Act) and ConocoPhillips Co. v. EPA (in which the 5th Circuit subsequently upheld additional cooling water intake structure regulations)
• Friends of the Everglades v. EPA (in which the 11th Circuit determined that EPA’s Water Transfer Rule is reviewable by the federal district courts rather than by the courts of appeals)

Mr. Lorenzen also worked closely over the years with the White House, EPA and other federal agencies to develop many of the rules that he and his team later defended. He is a recipient of numerous Department of Justice awards, including the prestigious John Marshall Award for Providing Legal Advice, awarded by the Attorney General in 2010 for his work with the White House, EPA and the Department of Transportation in developing the Light-duty Motor Vehicle Greenhouse Gas Rule.

For 12 years before joining the Department of Justice in 1997, Mr. Lorenzen was in private practice, where he developed expertise in environmental compliance counseling and due diligence, trial court and appellate litigation, and corporate transactional practice. Mr. Lorenzen received his B.A. from the University of California, Los Angeles, in 1982 and his J.D. from the Harvard Law School in 1985.

Recent Comments by Thomas Lorenzen

• "Sorry, Jane! I read your question - "Why can’t one specific method that pollutes the air be told it cannot continue unless and until it can stop"
  Obama’s EPA to Cost Americans Billions of Dollars and Hundreds of Thousands of Jobs
• "To a very limited extent, that seems to be one of the things that EPA is suggesting in the proposed rule, Jane: reduce coal's emissions, or replace th"
  Obama’s EPA to Cost Americans Billions of Dollars and Hundreds of Thousands of Jobs
• "I've been enjoying this excellent discussion from the"
  Obama’s EPA to Cost Americans Billions of Dollars and Hundreds of Thousands of Jobs