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Biography

Matthew represents plaintiffs and defendants in Superfund and other litigation matters regarding the cleanup of hazardous waste sites. He also represents buyers, sellers, and developers of contaminated properties, including parties seeking qualification for tax credits and other benefits provided by New York State’s Brownfield Cleanup Program. Matthew’s practice also includes assisting clients with a wide variety of environmental compliance matters.

Matthew is a former Assistant Attorney General in the New York State Office of the Attorney General’s Environmental Protection Bureau. In that role, he represented New York State and its agencies in Superfund matters; litigation against the federal government and private parties seeking in excess of $50 million for PFAS contamination at 69 sites; litigation against an international organization seeking more than $40 million in flooding damages; and other environmental enforcement matters.

Prior to joining the Attorney General’s Office, Matthew was in private practice in New York City. He also served as a law clerk to the Honorable Richard Owen of the U.S. District Court for the Southern District of New York.

Matthew is a member of the Executive Committee of the Environmental and Energy Law Section of the New York State Bar Association and Co-Chair of the Section’s Enforcement and Compliance Committee. He also is a member of the Board of Directors of the New York City Brownfield Partnership. Matthew regularly writes about environmental law issues and speaks on environmental law programs hosted by the Section, the NYC Brownfield Partnership, and other organizations.

 

Other Info About Matthew

Education

Law School

Boston University School of Law, J.D.

  • Selected for the Sutherland Cup Constitutional Law Moot Court Competition in Washington, DC
  • Edward C. Stone Moot Court
  • President of the Jewish Law Students Association, 2006-2007
Undergraduate School

University of Michigan, B.A.

Clerkships

Matthew served as a clerk for the court(s) and judge(s) below:

Judicial clerk to the Honorable Richard Owen, United States District Court for the Southern District of New York, New York, NY, 2008 – 2010

Bar Memberships

Matthew is licensed to practice in the following state(s):

New York

New Jersey

Courts

Matthew is admitted to practice before the following court(s):

United States District Court for the Eastern District of New York, United States District Court for the Northern District of New York, United States District Court for the Southern District of New York, United States District Court for the Western District of New York, United States District Court for the District of New Jersey

Recognition

Local & National Recognition

Award Selection Methodology

Recognized by Best Lawyers®, 2026-2027 Edition: Environmental Law; Litigation – Environmental

Included on the New York Metro Super Lawyers Rising Stars list, Business Litigation, 2014-2016

Professional Affiliations

Professional Affiliations & Memberships

New York State Bar Association
Executive Committee, Environmental & Energy Law Section, 2019 – Present
Co-Chair, Enforcement and Compliance Committee, Environmental & Energy Law Section, 2019 – Present
Member, Global Climate Change Committee, Environmental & Energy Law Section
Member, Hazardous Waste/Site Remediation Committee, Environmental & Energy Law Section

Co-Chair and Principal Organizer, Earth Day Climate Change Symposia, 2020-2025, sponsored by the New York State Bar Association and New York City Bar Association

New York City Bar Association
Member, International Human Rights Committee, 2016 – 2019

Member, New York City Brownfield Partnership Board of Directors

Civic Activities

Civic & Charitable Organizations

Mr. Sinkman has regularly provided pro bono legal services while working in the private sector. His pro bono work has included representing an applicant for refugee asylum status based on religious and political persecution and representing clients in landlord-tenant matters.

Hillside Food Outreach – Volunteer

Presentations

Matthew was invited to speak at the following events:

Speaker, “BCP Lessons Learned and Strategic Remediation Planning,” Second Annual Innovative Development Summit September 8, 2025

Speaker, “The Forever Chemical in New Jersey: Liability and Insurance,” July 10, 2025

Program Chair, Sixth Annual Earth Day Climate Change Symposium 2025 April 22, 2025

Speaker, The New York City Brownfield Partnership Redevelopment Roundtable, New York State Department of Environmental Conservation’s proposed regulations for the Brownfield Cleanup Program, March 25, 2025

Speaker, New York City Brownfield Partnership, “Innovative Development Summit,” September 9, 2024

Co-Chair, New York City Bar, Webinar, “The Fifth Annual Earth Day Climate Change Symposium,” April 22, 2024

Moderator, NYSBA, “Federal Civil Environmental Enforcement 101 & Advanced Topics: Current and Former Regulators Provide their Perspectives,” March 14, 2024

Speaker, New York State Bar Association, Environmental & Energy Law Section Oil Spill Symposium 2023, “Proposed Changes to SCOs in Part 375 and Impacts on the Spills and Brownfield Cleanup Programs,” May 10, 2023

Speaker, New York City Bar Webcast, “The Fourth Annual Earth Day Climate Change Symposium – Climate Change: An Accelerating Transformation,” April 20, 2023

Speaker, New York State Bar Association, “Superfund/Brownfield Program Update 2022,” December 7, 2022

Speaker, New York State Bar Association Webinar, “The Supreme Court’s Decision In West Virginia V. EPA: What It Means For Limiting Greenhouse Gas Emissions From Power Plants And For The Future Of Administrative Law,” July 13, 2022

Speaker, Celesq Attorneys Ed Center Webinar, “2022 Amendments to New York State’s Brownfield Cleanup Program,” June 28, 2022

Co-Chair, New York City Bar Association, “2nd Annual Earth Day Climate Change Symposium: Interdisciplinary Panels of Experts Address Governmental Responses to the Increasing Impacts of Climate Change,” Earth Day, April 22, 2021

Panelist, New York State Bar Association, Superfund Update, the United States Supreme Court’s decision in Atlantic Richfield Co. v. Christian, December 2, 2020

Co-Chair, New York City Bar Association, “Climate Change: How Bad Will it Be, and What Must Be Done? Inter-Disciplinary Panels of Leading Experts Answer these Questions on the 50th Anniversary of Earth Day,” Earth Day, April 22, 2020

Panelist, New York State Bar Association, Superfund Update, New York Attorney General Superfund litigation and an analysis of the United States Supreme Court case Atlantic Richfield Co. v. Christian, December 12, 2019

Panelist, New York State Bar Association, “Emerging Contaminants and Expanding Toxic Torts,” October 2018

Major Publications

Matthew is an author or contributor to the following publications:

Recent Amendments to New York State’s Superfund Law, The New York Environmental Lawyer, Volume 45, Issue 2 · August 26, 2025

The Forever Chemical: Regulation, Litigation and Insurance, MEALEY’s Emerging Toxic Torts, Vol. 34, #10 · August 19, 2025

NYSDEC Proposes Amendments to Cleanup Program Regulations, Gibbons Law Alert · March 25, 2024

Sinkman promoted to director at Gibbons, Roi-NJ · January 9, 2024

Making Sense of Efforts to Regulate PFAS, LexisNexis New York Newsletter, Environmental Law, Volume 35, No. 01 · January 2, 2024

New York State Enlists Brownfields in Effort to Achieve Climate Goals, New York State Bar Association Earth Week Blog · April 19, 2023

New Enforcement Rules for New York City Environmental Remediation Programs, Gibbons Law Alert · February 13, 2023

State Budget Amends and Extends Brownfield Cleanup Program, New York Law Journal · May 2, 2022

High Court Clean Air Fight May Transform Administrative Law, Law360 · March 4, 2022

In a Case of First Impression in the Second Circuit, the District Court Clarifies When the Statute of Limitations Begins to Run on a Natural Resource Damages Claim Under CERLCA, Gibbons Law Alert · February 17, 2022

 

 

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