David J. Armstrong


David J. Armstrong counsels clients on environmental risks and liabilities in corporate and real estate transactions and regulatory compliance. David has significant experience assisting clients in the defense of administrative and civil proceedings involving permitting and environmental enforcement matters at the federal and state levels. He also has experience conducting environmental due diligence, negotiating environmental indemnity agreements and environmental insurance policies, and providing advice on environmental issues in a variety of transactions.

David regularly litigates environmental matters for industrial, manufacturing, and commercial clients across the country in federal and state courts, in administrative tribunals, and before arbitrators and mediators.


Representative Matters

Enforcement and Litigation

  • Represents a property owner in environmental litigation against a manufacturing tenant that caused substantial contamination of property near Reno, Nevada
  • Represents a regional convenience store chain in defense of a RCRA 7003 Order issued by the federal Environmental Protection Agency and federal, state, and tribal court litigation related to that order
  • Serves as lead counsel for an Arizona utility in the defense of a $40 million federal Superfund claim for alleged groundwater contamination in metropolitan Phoenix

Professional Highlights

Professional Activities

State Bar of Arizona
Member, Environmental and Natural Resources Law Section

Arizona Forward, Member

Recognition & Accomplishments

Chambers USA, environment (including water rights), 2013-2021

The Best Lawyers in America, environmental law, 2013-2022

The Legal 500 US, energy – renewable/alternative, 2014-2015

Named to Who's Who Legal: Environment, 2012, 2014, 2015, 2019, 2020, 2021

Board Memberships & Community Service

Association of Arizona Food Banks, Chairman of the Board

Arizona Petroleum Marketers Association, Member, Board of Directors



Temple University James E. Beasley School of Law (J.D. 1992)
Editor-in-Chief, Temple Environmental Law & Technology Journal; Recipient, Barrister Award for Trial Advocacy

College of Charleston (B.A. 1985)




U.S. District Court for the District of Arizona

U.S. District Court for the District of New Jersey

U.S. District Court for the Eastern District of Pennsylvania

U.S. Court of Appeals for the Ninth Circuit

Federal courts in Connecticut, Nevada, New York, and Oregon and the Navajo Nation Tribal Court (admitted pro hac vice)