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Robert W. Petti

Of Counsel |
Of Counsel | Chicago, IL
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Robert Petti is a seasoned attorney with a focus on environmental law and complex civil litigation. Immediately prior to joining Segal McCambridge Singer & Mahoney, Mr. Petti worked as an attorney in the Illinois Attorney General’s Environmental Enforcement Bureau, where he focused solely environmental litigation and permitting matters. 

Mr. Petti holds a bachelor of science degree in geology and environmental resource management, and employs his scientific knowledge to guide his understanding of the often complex network of technical issues pervasive in environmental matters. He has utilized this unique background to achieve successful outcomes before trial and appellate courts and administrative boards on an array of environmental concerns including CERCLA (Superfund), RCRA, EPCRA, the Clean Air Act, and the Clean Water Act.  Mr. Petti has also used his scientific background to aid in the litigation of complex construction matters involving defect claims, contract performance disputes, and mechanics lien litigation. His experience working with small and midsize businesses, as well as major industrial and commercial entities, has taught him that understanding the varied challenges faced by businesses of all sizes is an important part of reaching a positive resolution in all matters.

Mr. Petti has worked in state government and litigation firms in Chicago and Denver, CO. He earned his J.D. from DePaul University College of Law, where he was a member of the writing staff of the DePaul Environmental Law Digest.  Mr. Petti is a member of several industry organizations, including the Environmental Law Institute and the Chicago Bar Association Environmental Law and Administrative Law Sections.

Mr. Petti is an avid skier who was born and raised in southeast Michigan and now resides in Wilmette, Illinois, with his wife and two children. 

Professional & Civic Involvement

  • Environmental Section of the Colorado Bar Association, Advisory Council (2002-2005)
  • Co-chair, CLE on Brownfields redevelopment, Denver, CO (2004)
  • Environmental Law Institute, Associate Member
  • Chicago Bar Association, Environmental Law Section and Administrative Law Section

representative matters

  • People of the State of Illinois v. ExxonMobil Oil Corp.: Settlement of suit involving aerial release of petroleum refining products over a four mile radius of residential and agricultural property following sudden discharge from refinery’s coking unit.
  • Rock River Water Reclamation District v. Illinois EPA: Successfully litigated a construction permit appeal involving expansion of a municipal water reclamation facility through hearing.
  • Prairie Rivers Network, et. al. v. Illinois EPA: Obtained summary judgment defending NPDES permits for water treatment facilities, including the world’s largest facility.
  • People of the State of Illinois v. Aero Specialties, Inc.: Successfully tried matter involving improper waste characterization and disposal at an industrial coatings facility.
  • People of the State of Illinois v. STAR Used Tires & Disposal, et. al.: Obtained summary judgment and injunctive relief for closure of largest waster tire disposal site in Illinois. 



DePaul University College of Law, J.D. (2000)

Western Michigan University, B.S., Geology and Environmental Resource Management (1996)


  • Colorado, 2001
  • Illinois, 2008
  • U.S. Court of Appeals for the Tenth Circuit
  • U.S. District Court for the District of Colorado