Experience 

John Hahn serves as firmwide Practice Leader for Mayer Brown’s Environmental practice.  His practice encompasses environmental counseling and litigation, often involving contaminated sites and issues of successor liability. He also has extensive experience with environmental challenges to real estate development and the allocation of environmental liabilities in corporate and real estate transactions. John received the Oak Leaf Award from The Nature Conservancy for his pro bono work in support of conservation projects. He joined Mayer Brown as a partner in 2000.

Education 

Yale Law School, JD, 1977 • Duke University, AB, magna cum laude, 1974

Admitted

• US Court of Appeals for the First Circuit, 2007
• US Court of Appeals for the Eighth Circuit, 1993
• US Court of Appeals for the Federal Circuit, 1983
• US Supreme Court, 1981
• US Court of Appeals for the District of Columbia Circuit, 1978
• US District Court for the District of Columbia, 1978
• Court of Appeals for the District of Columbia, 1977
• District of Columbia, 1977