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D. Lee Decker
Shareholder

(602) 530-8135dld@gknet.com

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 the 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.

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D. Lee Decker

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 benefit Arizona's mining industry. Since 2001, he has served as co-chair of the Arizona Chamber of Commerce and Industry Water Quality Subcommittee (formerly the Arizona Association of Industries Water Quality Subcommittee), 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.

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, 2013-2025; Natural Resources Law, 2015-2025; Litigation - Environmental, 2017-2025
  • Chambers USA®, Environment, 2014-2024
  • AzBusiness Leaders, Natural Resources & Water Law, 2024
  • Arizona Mining Association, Champion for the Mining Industry, 2021

News

  • Best Lawyers in America® 2025 Recognizes 51 Gallagher & Kennedy Attorneys - August 15, 2024
  • Gallagher & Kennedy Awarded Top Rankings in Chambers USA 2024 - June 6, 2024
  • Seven G&K Attorneys Named 2024 AzBusiness Leaders - December 28, 2023
  • Best Lawyers in America® 2024 Recognizes 52 Gallagher & Kennedy Attorneys - August 21, 2023
  • Gallagher & Kennedy Awarded Top Rankings in Chambers USA 2023 - June 1, 2023
  • Best Lawyers in America® 2023 Recognizes 41 Gallagher & Kennedy Attorneys - August 18, 2022
  • Gallagher & Kennedy Awarded Top Rankings in Chambers USA 2022 - June 20, 2022
  • Best Lawyers in America® 2022 Recognizes 37 Gallagher & Kennedy Attorneys - August 19, 2021
  • Gallagher & Kennedy Awarded Top Rankings in Chambers USA 2021 - May 20, 2021
  • Best Lawyers in America® Recognizes 36 Gallagher & Kennedy Attorneys - August 21, 2020
  • Gallagher & Kennedy Achieves Top Rankings in 2020 Chambers USA - May 15, 2020
  • Best Lawyers in America® Recognizes 33 Gallagher & Kennedy Attorneys as Leaders in Their Field - August 15, 2019
  • Gallagher & Kennedy Achieves Top Rankings in 2019 Chambers USA - April 29, 2019
  • Best Lawyers in America® Recognizes 35 Gallagher & Kennedy Attorneys as Leaders in Their Field - August 15, 2018
  • Gallagher & Kennedy Achieves Top Rankings in 2018 Chambers USA - May 17, 2018
  • New Mexico Supreme Court Rules in Favor of Gallagher & Kennedy Client Freeport-McMoRan in “Copper Rule” Case - March 9, 2018
  • 35 Gallagher & Kennedy Attorneys Recognized as 2018 'Best Lawyers in America®' - August 16, 2017
  • Gallagher & Kennedy Attorneys & Practice Areas Recognized by Chambers USA 2017 - May 31, 2017
  • 33 Gallagher & Kennedy Attorneys Named 2017 ‘Best Lawyers in America®’ - August 17, 2016
  • Gallagher & Kennedy Receives Top Rankings From Chambers USA 2016 - May 27, 2016
  • Florence Copper Project Backed by Most at Hearing - May 23, 2016
  • G&K Attorneys Named to 2016 'The Best Lawyers in America®' List - August 17, 2015
  • G&K Achieves Top Rankings from Chambers USA 2015 - May 19, 2015
  • G&K Attorneys Named to 2015 'The Best Lawyers in America®' List - August 18, 2014
  • Gallagher & Kennedy Achieves Top Rankings from Chambers USA 2014 - May 30, 2014
  • 36 G&K Attorneys Named to 2014 Best Lawyers in America® List - August 15, 2013
  • Nearly Two-Thirds of G&K's Shareholders Named "Best Lawyers in America" - August 22, 2012
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Publications

  • Points to Consider on ADEQ's Legacy Mine Remediation Efforts - January 5, 2021

Events

  • "Water Quality Regulatory Developments," Presented at 2024 Society for Mining, Metallurgy, and Exploration (SME) Conference - November 11, 2024
  • 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

PRACTICE AREAS

  • Administrative & Regulatory
  • Environmental & Natural Resources
  • Government Affairs
  • Agribusiness

Bar & Court Admissions

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

Education

  • Brigham Young University
    J.D., magna cum laude, 1990
    Order of the Coif, Editor, Law Review
  • Brigham Young University
    B.A., cum laude, 1987

Contact G&K

 

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Phone: (602) 530-8000
Fax: (602) 530-8500
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Santa Fe, NM 87501

Phone: (505) 982-9523
Fax: (505) 983-8160
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