“… a ‘subject matter expert’ in environmental law claims, with interviewees valuing his ‘very practical’ approach and his ‘business mindset’ in litigation matters.”
Chambers USA 2018


Mark Ter Molen is a litigator and environmental lawyer with a particular emphasis on large environmental tort cases involving hundreds if not thousands of claimaints and complex environmental and general civil matters. For 30 years, Mark has represented clients in: complex federal and state trials and appeals, including putative class actions; complex environmental trials and appeals, including governmental enforcement as well as private party litigation; and environmental regulatory hearings and appeals conducted before state and federal agencies. He also provides general corporate counseling on environmental compliance issues and environmental concerns in the context of corporate transactions; supervises environmental remediations pursuant to various state and/or federal requirements; and conducts condemnation and property valuation actions.

Mark is the co-chair of Mayer Brown’s Environmental Litigation group, which was named as one of the “Environmental Litigation Groups of the Year” by Law 360. Mark is also the former chair of Mayer Brown’s mass tort litigation group. He has been listed among The Best Lawyers In America (2017-2019), in the fields of Environmental Law and Environmental Litigation for the third consecutive year, and in 2014, Mark was named a “Client Service All-Star” by BTI Consulting, which identified just 330 lawyers nationwide as providing exceptional service, based on client interviews. Among other accolades, Mark has been selected repeatedly as a Leading Lawyer in Environmental Law and Toxic Tort Defense Law by the Law Bulletin Publishing Company's Leading Lawyers Network; as an Illinois "Super Lawyer;" and is listed in Chambers USA, “America's Leading Lawyers for Business” directory, the Legal 500 for litigation, and various other allegedly prestigious lawyer rating services. In 1996, Mark was honored with the Illinois State Bar Association’s John C. McAndrews Pro Bono Service Award for outstanding pro bono work in the state for his work in reversing the conviction of a man on Illinois’ death row and subsequently establishing his actual innocence.

Spoken Languages

  • English


Product Liability, Environmental, and Mass Tort Claims. Represents manufacturing and chemical clients in individual claims, “mass” claims, and class action toxic cases in federal and state courts, including defending class certification efforts. Experienced with medical claims alleging injuries due to heavy metal exposure, particle inhalation, benzene, PAHs, diacetyl/food flavorings, solvents, dioxin, asbestos, airline disinsectants, and inhalation of toxic fumes/gases. Also deals with property damage claims alleging diminution of value due to contamination of soils and/or contamination of groundwater. Representative clients include Cargill, Chemtura, Dow Chemical, Nicor Gas, Pactiv, Ryerson, Kerry Foods, and Union Carbide. Currently serving as national counsel for Dow and Union Carbide in ethylene oxide litigation and for Chemtura in food flavorings litigation.

Recent Results:

  • City of Evanston v. Nicor Gas Co., et al. Ongoingrepresenting Nicor in RCRA citizens’ suit brought by the City of Evanston alleging that contaminants from a former manufactured gas plant have contaminated the City’s water supply. The initial complaint by the City was dismissed after the court determined, among other findings, that methane gas allegedly leaking from operating natural gas pipelines did not qualify as a “solid waste” for purposes of RCRA.
  • Flint Water Litigation. Ongoing - representing Veolia Environnement in the substantial litigation in state and federal court alleging damages associated with exposures to lead and Legionella bacteria resulting from the Flint, Michigan, water crisis.
  • Nicor Gas Co. v. Wisconsin Central LTD. Represented Nicor in this successful preliminary injunction action in Cook County related to efforts by Nicor to reconnect a major gas line that ran beneath Wisconsin Central railroad tracks in time for the winter heating season.
  • Wisconsin Central v. Nicor Gas Co. et al. Ongoing - representing Nicor in this lawsuit seeking damages resulting from a railroad derailment, which derailment Wisconsin Central blamed on work by a Nicor pipe installation contractor, Michels, beneath certain Wisconsin Central railroad track.
  • Hamilton-Warwick v. Volkswagen Group et al. Ongoingrepresenting BMW in this lawsuit seeking damages associated with the alleged use of monkeys in testing for the toxicity of diesel vehicle emissions.
  • Paulsboro Derailment Litigation. Ongoing representing CSX in the significant litigation associated with the derailment of a train, and a related chemical release, in Paulsboro, NJ. On behalf of CSX we defeated class certification for the numerous putative class cases, won summary judgment for all of the several hundred federal court cases, and won summary judgment as well for several thousand of the pending state court cases.
  • Shakir v. Bergman, et al, and related cases associated with the mass 2012 highway accident in Northwestern Indiana. Represented CSX in these cases alleging damages associated with multiple vehicle collisions, where the collisions were allegedly caused by thick smoke from a roadside fire allegedly caused by CSX. Successfully resolved cases after expert discovery with pending Daubert motions highlighting the impossibility of CSX having caused the fire.
  • Metropolitan Water Reclamation District of Greater Chicago v. Northern Illinois Gas Company, et al. Successfully resolved litigation brought by the Metropolitan Water Reclamation District against Nicor and ComEd/Exelon regarding clean up of 18-acre parcel that was formerly the site of a manufactured gas plant. (Fall 2011).
  • Avila, et al, v. CNH, et al, and Schwan, et al, v. Cargill. Won summary judgment on all claims on behalf of Cargill in consolidated litigation brought by approximately 300 plaintiffs (recruited by Erin Brockovich) alleging personal injury and property damage associated with chlorinated solvent groundwater contamination in Nebraska. (January 2009).
  • Blaylock, et al, v. Sigma Aldrich, et al. Won summary judgment/dismissal on all claims on behalf of Chemtura in this food flavorings lawsuit pending in St. Louis. (October 2008).
  • Gray, et al, v. Derderian, et al. Won summary judgment on all claims on behalf of defendant in tragic "Station Fire" litigation arising out of Providence night club fire that killed and injured over 400 individuals. (Spring 2008).
  • Liesse, et al, v. AGA, et al. Won summary judgment on all claims on behalf of Dow Chemical and Union Carbide where 24 Chicago-area hospital workers alleged various personal injuries associated with exposure to ethylene oxide, which was used as a medical sterilant. (Spring 2007).

Governmental Enforcement Actions. Represented manufacturing, chemical, and farming clients in governmental enforcement actions arising out of alleged violations of environmental laws and/or permits seeking significant fines and/or closure of the facility. Served as lead counsel in United States v. Tarkowski, resulting in first reported defeat at trial of a USEPA demand to conduct a removal action.

Private Cost Recovery Claims. Represented numerous clients in federal and state courts prosecuting and/or defending suits seeking recovery of cleanup costs, including experience with private CERCLA cost recovery actions as well as contractual cost recovery claims, including lead counsel in plaintiff action that succeeded in obtaining attorneys' fees and consultant costs.

Governmental Cost Recovery Claims. Represents clients in federal and state courts in suits seeking to recover environmental cleanup costs, including dealing with issues of allocation and appropriate remediation, as well as with national resource damages claims.

Administrative Actions. Represented clients in numerous environmentally-related agency proceedings, including administrative enforcement actions, permit hearings and appeals, and variance requests before the Illinois Pollution Control Board, and permit appeals and administrative enforcement actions before the United States Environmental Protection Agency.

Environmental Disaster Response/Litigation. Represented manufacturing and refining clients responding to industrial "disaster" incidents, such as plant explosions and sudden fires, including developing and implementing strategies for addressing legal, media, employee, and insurance issues, and handling lawsuits arising from the incidents.

Citizens' Suits. Represented industrial clients in numerous suits brought by citizens' groups seeking substantial fines for alleged violations of environmental laws and permits.

General Environmental Counseling. Counsels a variety of clients on all aspects of environmental law, including wetlands, permitting issues, hazardous waste disposal, climate change, and general liability risks.

Death Penalty Litigation. Served as lead counsel in People v. Jimerson, a seven-year effort that succeeded in persuading the Illinois Supreme Court in 1995 to reverse the conviction and death sentence of Verneal Jimerson, who was tried and convicted in 1985. During retrial, succeeded in establishing Jimerson’s innocence and winning dismissal of the charges. Illinois Governor Edgar subsequently granted a pardon on the basis of actual innocence.

Civil Rights Litigation. Prosecuted claims for violation of rights and wrongful imprisonment under federal civil rights laws and state counterpart tort claims, including Jimerson v. Capelli, et al., which resulted in a $36 million settlement for malicious prosecution and wrongful imprisonment.


The University of Chicago Law School, JD

Cornell University, AB, magna cum laude


  • Illinois


  • US Court of Appeals for the Seventh Circuit
  • US District Court for the Northern District of Illinois


  • Founding president of Baker Demonstration School, a 400 student pre-K through 8th grade independent school in Wilmette, Illinois, 2003 to date
  • Various church and municipal volunteer positions
  • American Bar Association, Standing Committee on Environmental Law, Section on National Resources
  • Illinois State Bar Association