William Walsh



William J. Walsh is a partner in the Washington, D.C. office of Lewis Brisbois, a member of the Administrative Law & Regulatory Practice and the Environment, Land, & Natural Resources Law Practice. He principally focuses his practice in the areas of government policy advocacy, regulatory compliance and counseling and environmental litigation. Bill advises companies and industry trade associations on compliance with wide range of environmental laws (including the Toxic Substance Control Act, the Federal Insecticide Fungicide, and Rodenticide Act (FIFRA), the Clean Water Act, the Resource Conservation and Recovery Act, the California Safe Drinking Water and Enforcement Act (commonly referred to as Proposition 65), and the California Safer Consumer Product (SCP) regulations, among other statutes and regulations). Bill assists clients in identifying and mitigating business risks associated with increasingly complex product safety and chemical ingredient regulations developed pursuant to these environmental statutes and various product safety statutes (e.g., the Consumer Product Safety Act, the National Highway Safety Act). He also defends regulatory enforcement actions and personal injury/property damage liability litigation. He advocates changes to environmental regulations and policies and provides counsel on a broad range of environmental issues involving innovative scientific, regulatory, legal and policy questions. Bill is listed in Chambers USA: America’s Leading Lawyers for Business.

Prior to joining Lewis Brisbois, Bill was an associate, partner, and eventually Of Counsel at one major U.S. based law firm (from 1986 to 2016) and a Senior Counsel at another major law firm (from 2016 through 2019). Prior to that, Bill served as the chief of the Environmental Protection Agency’s (EPA) Drinking Water and Wetlands Enforcement Branch and was lead EPA counsel on the precedent-setting hazardous waste lawsuits brought against Occidental Chemical Corporation concerning the Love Canal and related landfills.

Bill has served on more than 13 NAS Committees, including Committees that authored reports on Alternatives for Ground Water Cleanup (1994) and Alternatives for Managing the Nation's Complex Contaminated Groundwater Sites (2013), evaluations of the hazardous waste remediation process and the limits to remediation technology.

Bill has written and spoken on a wide range of topics, including regulation and cleanup levels, choosing cleanup goals and technologies, the use of groundwater models in the regulatory system, and the distinction between personal injury claims and regulatory limits.

Primary Area(s) of Practice

  • Administrative Law & Regulatory Practice
  • Environment, Land, & Natural Resources Law
  • Per- and Polyfluoroalkyl Substances (“PFAS”)
  • Sustainability and Environmental, Social, and Governance (ESG) Practice


District of Columbia

U.S. District Ct., District of Columbia

U.S. Court of Appeals for the District of Columbia Circuit


  • American Bar Association, Section of Environment, Energy, and Resources
  • American Bar Association, Section of Administrative Law & Regulatory Practice
  • District of Columbia Bar, Section of Environment, Energy and Natural Resources
  • District of Columbia Bar, Section of Administrative Law and Agency Practice

Awards & Honors

  • EPA Special Achievement Awards
  • EPA Bronze Medal for Commendable Service
  • U.S. Department of Justice Certification of Commendation
  • Selected to serve on 13 National Academies of Science (NAS) Committees providing advice to federal agency on a wide array of environmental and waste disposal issues
  • Associate of the National Academies of Science
  • Certificate of Appreciation, NAS
  • Medal of Excellence, Army's Assembled Weapons Alternatives Program

Professional Presentations

  • Beyond Ebola: Environmental, OSHA, and Other Regulatory Issues Creating Business Risks to Healthcare Providers in the Future, March 25, 2015
  • Vapor Intrusion Toxic Torts: Emerging Trends in Litigation, Risk Analysis, Regulatory Standards, Measurement and Monitoring, October 9, 2014
  • Invited Participant at Green & Sustainable Remediation Roundtable, June 3, 2014
  • Safer Consumer Products Regulations, July 31, 2013


George Washington University Law School, Washington DC

Juris Doctor

  • Order of the Coif

Manhattan College, New York

Bachelor of Science in Physics, cum laude


  • Quoted, “Honeywell, Chemours Among PFAS Makers on EPA Chemicals List (2),” Bloomberg Environment (March 2020)
  • Regulating PFAS will be harder than you think. Op-Ed Contributor. Pennsylvania Capital Star (April 10, 2019), available at https://www.penncapital-star.com/commentary/regulating-pfas-will-be-harder-than-you-think-this-is-why-opinion/
  • "Manufacturers using perfluorinated chemicals should follow new regulations," Rubber & Plastics News, March 2018.
  • Co-author, "White House Deregulation Push Is Just Getting Started," Law 360, January 2018
  • "Honestly, What Is The Best Science?", Law360 - April 25, 2017
  • When May a Previously Approved Site Closure Not Provide Closure - Reopening Vapor Intrusion Sites Client Alert, March 22, 2016
  • What Does the Health Care Industry Do Now When Disposing "Hazardous Waste" Pharmaceuticals? Client Alert, February 29, 2016
  • Changing The EPA's Opaque Scientific Methods 1/20/2016, published in the Environmental, Product Liability, and Public Policy sections of Law360 on January 20, 2016, available at https://www.law360.com/articles/747498/changing-the-epa-s-opaque-scientific-methods
  • EPA'S Hazardous Waste Pharmaceuticals Rules May Impose Significant Burdens on Health Care Facilities Client Alert, October 29, 2015
  • Six Things the Private Sector Should Know about EPA's Final Vapor Intrusion Guidance Environmental Law Alert, August 24, 2015
  • Beyond Ebola: Environmental Regulatory Issues Creating Business Risks for Health Care Providers Health Care Law Alert, June 25, 2015
  • D.C. Circuit Rules a Provision of the SEC Conflict Minerals Rule Violates the First Amendment, April 17, 2014
  • DTSC Announces Initial Proposed Priority Products List under the Safer Consumer Products Program - The First Green Chemistry Shoe Drops, March 13, 2014
  • Destroying Chemical Weapons* October 11, 2013
  • The President’s Climate Action Plan: What Might it Mean for Existing Coal-Fired Plants?, August 6, 2013
  • Court to Decide Whether FDA Regulation of Lead in Baby Food Pre-empts California Proposition 65, June 10, 2013
  • How Are We Doing? The Mercury Story, February 14, 2013
  • Disposing of Pharmaceutical Waste: Some Progress, January 22, 2013
  • Free Webinar to Examine Report's Call for Cleanup Programs to Move from Problem Identification and Remedy Selection to Long-term Management, November 27, 2012
  • National Academy of Sciences Group Recommending Methods to Facilitate Transition of Cleanup Programs from Problem Identification and Remedy Selection to Long-term Management, November 8, 2012
  • In 2014, New Standards Will Govern Amounts of Lead Allowed in Certain Plumbing Fixtures, September 21, 2012
  • An Evaluation of Chemical Contamination in the Aftermath of Hurricane Katrina. Author: William J. Walsh. Published in The Bureau of National Affairs, Inc., November 6, 2006

Published Opinions

  • United States v. Hooker Chemicals & Plastics Corp. (Hyde Park Landfill, 540 F. Supp. 1067 (W.D.N.Y. 1982)
  • United States v. Hooker Chemical & Plastics Corp. (S Area Landfill), 607 F. Supp. 1052 (W.D.N.Y. 1985)
  • United States et al. v. Hooker Chemical & Plastics Corp. (S Area Landfill), 749 F.2d 968 (2nd Cir. 1984)
  • United States et al. v. Hooker Chemical & Plastics Corp. (S Area Landfill), 776 F.2d 410 (2d Cir. 1985)

Pro Bono & Philanthropy

  • Served on approximately fourteen National Academies of Science Committees and was selected as an Associate of the National Academies of Science.