Alexander Arensberg represents clients on a wide range of matters, focusing particularly on public lands and natural resource law, environmental compliance matters, and environmental, natural resource and complex commercial litigation. Alexander has significant experience with all major federal environmental statutes, including the Comprehensive Environmental Response Compensation and Liability Act (CERCLA), Resource Conservation and Recovery Act (RCRA), Clean Water Act, Clean Air Act, Endangered Species Act, the National Environmental Policy Act (NEPA) and counterpart state laws, particularly in California, Colorado, Nevada and New Mexico.

    In connection with his complex commercial litigation work, Alexander has developed significant experience in electronic discovery, including collection, management, review, application of data analytics and production of electronic documents. Alexander also advises clients with regard to facility siting, permitting and regulatory compliance arising under federal, state and local environmental laws.

    Alexander graduated from the University of California Berkeley School of Law, where he was the senior executive editor of the Ecology Law Quarterly and received a Certificate of Specialization in Environmental Law.

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    • Second-chaired 16-day federal bench trial defending Fortune 200 railroad company against US$140 million CERCLA contribution claim.
    • Represent multinational mining companies on compliance and permitting matters, particularly on Western public lands. Experience includes representing gold, silver, lithium, potash, copper and iron mining companies operating on BLM and USFS land in Colorado, Nevada, New Mexico and Arizona, on matters arising under NEPA, FLPMA, CWA, CAA, MBTA, NHPA, the General Mining Laws, the Mineral Leasing Acts and counterpart state laws.
    • Represented State Office of the Attorney General in multistate litigation before the US Supreme Court related to hazardous waste releases from abandoned mine. Assisted client in formulating litigation strategy, drafting substantive filings before the US Supreme Court, interviewing and selecting expert witnesses and managing discovery.
    • Represent Fortune 500 phosphate and potash producer on federal and state permitting matters related to tailings management, public land exchanges, mine and closure plan requirements, dam safety requirements, designations of Areas of Critical Environmental Concern (ACECs) and development of resource management plans.
    • Represent specialty chemicals company in litigation related to company’s right to mine lithium from groundwater brine in Nevada.
    • Represent Fortune 200 railroad company in complex environmental litigation before the D. Idaho, S.D. Mo., D. Colo., and appeals before the Eighth, Ninth and Tenth Circuits, including defending against claims brought under CERCLA, RCRA, CWA and state common law.
    • Experience drafting state and federal legislation, advising clients on public policy implications of legislative efforts, and participating in federal notice and comment rulemaking efforts.
    • Experience managing large-scale e-discovery projects and conducting internal investigations for both national and international clients.


    • University of California at Berkeley, Boalt Hall School of Law, J.D., 2012
    • University of Colorado at Boulder, B.A., magna cum laude, Phi Beta Kappa, 2007


    • Colorado, 2012

    Memberships and Affiliations

    • Colorado Bar Association
    • Recognized as a 2020 Super Lawyers Rising Star
    • Certificate of Specialization in Environmental Law, Berkeley Law
    • Senior Executive Editor, Ecology Law Quarterly 

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    • Speaker, “How to Mine Lithium from Groundwater – The U.S. Legal Framework,” 63rd Annual Rocky Mountain Mineral Law Institute, 2017.
    • Author, “Are Migratory Birds Extending Environmental Criminal Liability,” Ecology Law Quarterly, volume 38, p. 427, 2011.

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