I graduated from Yale University in 1979 and from New York University School of Law in 1985. After a clerkship with U.S. District Judge Barbara Crabb in Madison, Wisconsin, I began my career in environmental law in 1986 with the Washington D.C. office of Bryan Cave, where I developed an in-depth knowledge of hazardous waste law and regulation, representing trade associations and corporations in rulemaking, permitting, and compliance matters.  I moved to Bryan Cave’s New York office in 1987, and from there to the New York office of Morgan Lewis in 1990.  I created Mark C. Pennington LLC in July 2006. In November 2007, I joined the law firm of John E. Osborn P.C. as Of Counsel.

I am admitted to practice in the State of New York.
       

I am a member of the Hazardous Waste/Site Remediation Committee of the New York State Bar Association’s Environmental Law Section, which I assisted in preparing comments on New York’s brownfield program and regulations.
  

I am a long-time member of the New York City Bar, where I chaired the Environmental Law Committee’s subcommittee on Watershed from 1994 to 1996, and served as a member of the Transportation Committee from 1996 to 1998.
 

I am also a member of the American Bar Association, Section on Natural Resources, Energy and Environmental Law; the National Brownfield Association; the New York State Affordable Housing Association; and the Land Trust Alliance.