D. Lee Decker


D. Lee Decker

Lee practices environmental law involving water quality, water rights, environmental compliance auditing, solid and hazardous waste, mining and mined land reclamation and remediation, toxic substances and Superfund matters.  With more than 30 years of experience, Lee maintains a nationally-recognized water quality practice and works closely with his clients at the federal, state and local levels to develop workable strategies that promote development and expansion of both industrial and mining operations. In working with major industrial, mining, construction and development clients, Lee has honed his keen expertise in the field of environmental law, which is further supported by his unwavering commitment to professionalism and favorable results

Lee is one of the lead mining and industrial experts in the Southwest on state and federal-based water quality and mine reclamation and closure programs. His broad and deep experience  includes groundwater protection permit programs (such as Arizona’s aquifer protection permit program), point source discharge permit programs (including NPDES and 404 dredged and fill material permits), impaired water determinations and listings, development and implementation of total maximum daily load requirements, mined land reclamation and closure, development of surface and groundwater water quality standards, and state certification of federal water quality permits/approvals.

With decades of honed practice and hard-earned experience, Lee has proven he is able and willing to take on even the most complex matters and controversy by focusing on resolution rather than conflict. His expertise lies with analyzing, reconciling, and streamlining the legal and scientific issues inherent in such matters. His fluency in consultant reports and environmental studies have allowed him to make persuasive arguments to agency professionals so clients can obtain permits and progress on their projects.

Competence in and a multi-dimensional knowledge of the law, reconciliation of the science, and actionable solutions for his clients are what make Lee a stellar attorney. Clients turn to him because he delivers the highest quality advice and service. A testament to his decades of first-rate work, Lee’s clients have confidence in him and consistently rely upon his advice to ensure their viability today and into the future.

An active member of the Arizona Mining Association, Lee lobbies federal and state governmental agencies on water quality statutory, regulatory and policy-based issues to the benefit of the mining industry in Arizona.  He serves as the co-chair of the Arizona Chamber of Commerce and Industry Water Quality Subcommittee (formerly the Arizona Association of Industries Water Quality Subcommittee), a position he has filled since 2001 and which allows him to continue to shape the law and industry.

Representative Experience

  • Represented national and Arizona trade associations in federal court relating to the 2015 and 2020 regulatory definitions of “waters of the United States” under the federal Clean Water Act.
  • Assisted major industrial clients in obtaining water quality, water rights, and other environmental and natural resources-related permits and approvals on both a federal and state level.
  • Represented major mining clients in Arizona, Colorado, and New Mexico in obtaining permits and approvals for continuing operations, mine expansions, new mines, and mine closures and then defending such permits and approvals in administrative and judicial appeals.
  • Conducted numerous environmental compliance audits at domestic and international industrial facilities, including facilities located in Canada, Chile, and Venezuela.
  • Acted as lead legal counsel for industrial and mining clients in the preparation of comments and lobbying on federal and state environmental statutes and rules. Most recently, Lee participated in the development of new Arizona surface water protection legislation (HB2691 (2021)), Arizona underground injection control legislation (HB2042 (2021)), revisions to the federal National Environmental Policy Act (“NEPA”) regulations, federal and state stormwater permitting rules and implementing permits, and federal and state safe drinking water regulations.

Bar & Court Admissions

  • Arizona, 1990
  • U.S. District Court, District of Arizona, 1990

Associations & Memberships

  • State Bar of Arizona, Member
  • State Bar of Arizona, Environmental and Natural Resources Law Section, Member
  • Arizona Chamber of Commerce & Industry, Water Quality Subcommittee, Co-Chair
  • Arizona Mining Association, Water Quality Subcommittee, Vice-Chair
  • The Church of Jesus Christ of Latter-Day Saints, Member
  • J. Reuben Clark Law Society, Member

Honors & Awards

  • AV Preeminent Peer Review Rating, Martindale-Hubbell
  • Best Lawyers in America®, Environmental Law, 2013-2024; Natural Resources Law, 2015-2024; Litigation - Environmental, 2017-2024
  • Chambers USA®, 2014-2023
  • Arizona Mining Association, Champion for the Mining Industry, 2021

Press Releases

Speaking Engagements

  • Co-presenter, Life of a Permit, 2021 State Bar Convention: Updates in Arizona Environmental Regulatory Law, Arizona State Bar, June 16, 2021
  • Co-presenter, WOTUS Panel, Arizona Manufacturer’s Council Environmental Sustainability Virtual Series—Arizona Chamber of Commerce & Industry, July 10, 2020
  • Presenter, Complying with Arizona and Federal Water Quality Laws and Regulations, Arizona Water Laws and Regulations—Halfmoon Education Inc., January 29, 2020
  • Co-presenter, Rock Products Industry Focus Panel—Water Quality Issues, Environmental Professionals of Arizona 2018 Gatekeeper Regulatory Roundup, March 23, 2018