Matthew A. Walker

Matt Walker’s practice includes all areas of environmental law, including litigation, regulatory compliance, and assistance with corporate transactions. He utilizes his background working for environmental regulatory agencies to advise a wide range of clients on environmental matters under federal and state law, and in judicial and administrative forums.

Matt is well-versed in litigation matters involving the core environmental laws, including suits under the Clean Water Act, contaminants and toxic tort, enforcement actions for waste violations and issues surrounding state and federal CERCLA claims. Matt also focuses on monitoring state and federal investigation and regulation of PFAS, and helps businesses develop strategies to adapt to regulatory developments.

Matt's environmental regulatory work has involved handling complex site investigation and remediation projects, Clean Air Act and Clean Water Act permit modifications and compliance counseling and enforcement disputes. Relying on his technical background in environmental science, he works closely with consultants and state and federal government agencies to amicably resolve potential claims. Additionally, he assists buyers, sellers and financial institutions identify risks through environmental due diligence and negotiate contractual protections related to the sale and acquisition of businesses and property in a variety of industries.

Prior to joining Lathrop GPM, Matt served as an Assistant Attorney General with the Environmental Bureau of the Illinois Attorney General's Office, where he litigated matters relating to environmental, land use and energy disputes.

While in law school, Matt worked as a law clerk at the EPA (Region 5); the Environment and Natural Resources Division, Environmental Crimes Section, U.S. Department of Justice; the Aviation, Environmental, Regulatory and Contracts Division for the City of Chicago Department of Law; and Division of Legal Counsel, Office of Emergency Response of the Illinois Environmental Protection Agency.



  • Co-presenter, "PFAS Update for the Practitioner: What's in Store for 2023?" Illinois State Bar Association 21st Annual Environmental Law Conference, May 11, 2023
  • Presenter, "Environmental Justice: The Federal and State Governments’ Renewed Focus and the Regulated Industries’ Perspective.," Illinois State Bar Association, June 23, 2021
  • Presenter, "PFAS - Emerging Contaminants of Concern," Illinois State Bar Association Environmental Conference, May 13, 2021
  • Presenter, "Regulatory and Technical Strategies in Detecting and Quantifying Per- and Polyfluoroalkyl Substances," webinar, May 2020
  • Presenter, "The Evolving PFAS Regulatory Landscape, Chicago Bar Association Young Lawyers Division," January 2020
  • Presenter, "Environmental Enforcement Trends and Liability," June 2019
  • Presenter, "The Evolving PFAS Regulatory Landscape webinar," June 2019


  • Co-author, "State PFAS Requirements for Consumer Products Set to Go Into Effect in 2023 and Beyond," ALM |, January 27, 2023
  • Co-author, "PFAS in Agriculture: What Agri-Business Sector Needs to Know about the Latest Emerging Contaminants," Agricultural Business Council of Kansas City, November 29, 2022
  • Co-author, "The PFAS and the Furious: Evaluating EPA’s New PFAS Lifetime Health Advisories and Implications for the Future of PFAS Litigation," American Bar Association Section of Environment, Energy & Resources (SEER), September 2022
  • Co-author, "Food Packaging Emerges as PFAS Battleground," Food Industry Executive, May 24, 2021
  • Co-author, "Illinois Issues One of the Lowest Health Advisory Guidance Levels in the Nation," Illinois State Bar Association Environmental Law Newsletter, March 2021
  • Co-author, "What You Need to Know About PFAS Remediation in 2021," Industry Today, January 28, 2021
  • Author, "What to Expect from an Illinois Environmental Enforcement Action: A Review Amidst Covid-19 Confusion, The Illinois Manufacturer," November 2020
  • Co-author, "No Balance Required: A Review of Injunctive Relief Under the Illinois Environmental Protection Act," Illinois State Bar Association Environmental Law Newsletter, August 2020
  • Co-author, "A Nudge or a Shove: Environmental Federalism and Non-Point Source Pollution," 28 San Joaquin Agricultural Law Review 1-41 (2019)
  • Author, "The Wetter of Two Evils: Evaluation of the Necessity Defense Under the Clean Water Act," ABA YLD SEER Newsletter, Spring 2017
  • Co-author, "A Tale of Three Watersheds: U.S. EPA's Contrasting Approaches to Agriculture Nutrient Pollution," 2 WIREs Water 47, 2015
  • Author, "Where We're Going, We Don't Need (More) Roads," 2 Land Conservation Foundation 5, 2014

Client Alerts and Blog Posts

Professional Affiliations

  • Illinois State Bar Association, Environmental Law Section, Council Member
  • ABA Section of Environment and Energy Resources, Young Lawyers Division, Former Vice Chair
  • Air & Waste Management Association, Lake Michigan States Section


  • Selected among The Best Lawyers in America®, "Ones to Watch," 2024
  • Illinois Super Lawyers, "Rising Star," Environmental Litigation, 2023-2024
  • Missouri Lawyers Media, Top Legal Innovations Award, Emerging Practice Areas, PFAS
  • Environmental Moot Court, Editor, Awarded Best Brief and Best Overall
  • CALI Award, Top grade in class, Moot Court and Energy & Natural Resource Transactions
  • University of Illinois Men’s Lacrosse Team, Team Captain, MCLA Scholar-Athlete Award recipient
Photo of Matthew A. Walker
  • Chicago

    155 North Wacker Drive
    Suite 3000
    Chicago, IL 60606-1787
F: 312.920.3301


Maria Vargas

Court Memberships

  • Illinois


University of Illinois, J.D., cum laude, 2016

University of Illinois at Urbana-Champaign, M.S., Natural Resources and Environmental Science, 2016

University of Illinois at Urbana-Champaign, B.S., Natural Resources and Environmental Science, 2013