Cascadia Law Group

Environmental Attorneys in Seattle and Olympia

Stephen Tan

Stephen Tan photo
direct: (206) 292-2657

Stephen represents Fortune 500 companies, local businesses, municipalities, and nonprofit groups in environmental litigation and in disputes over insurance coverage for environmental liabilities. He has tried dozens of cases to verdict in state and federal courts in Washington, Alaska, Oregon, and California. Active in the nonprofit community, Stephen writes and speaks often about environmental and conservation policy and organizational development, strategy, and governance.


  • Represent clients in disputes over liability for environmental cleanup costs and natural resource damages under federal and state Superfund laws.

  • Represent clients in citizen suits brought under the Clean Water Act and RCRA.

  • Represent policyholders and insurance carriers in disputes over coverage for environmental liabilities under CGL and specialty environmental insurance products, and over claims handling, defense, and indemnity obligations.

  • Represent clients in claims arising from hazardous or noxious environmental conditions caused by operation of municipal and commercial facilities.

  • Represent clients in disputes over alleged negligent performance of environmental investigation and remediation services.

  • Advise and provide expert testimony to parties and counsel in cost recovery actions over scope of liability for remedial action costs and attorneys fees.

  • Advise and provide expert testimony to parties and counsel in disputes over insurance carriers' claims handling, defense, and indemnity obligations.

  • Certified Rule 39.1 attorney neutral for the Western District Court of Washington.

  • Counsel pro bono for environmental and advocacy groups including the Sierra Club, National Audubon Society, Wilderness Watch, Pacific Rivers Council, Washington Environmental Council, Olympic Park Associates, North Cascades Conservation Council, Alliance for the Wild Rockies, Defenders of Wildlife, Public Employees for Environmental Responsibility, and Label It Washington, in litigation and public interest advocacy.

  • Senior Associate, Valtas Group (2019 - present). Consultant to nonprofit leaders and boards on organizational development; strategic planning; leadership transitions; board development and evolution; the effective use of advisory boards; and diversity, equity and inclusion.

  • Adjunct Faculty, University of Washington Professional & Continuing Education (2009 – 2014). Instructor in Environmental Law & Regulation Certificate Program on endangered species protection, regulatory takings, ocean policy, and management of coastal and marine resources.

  • Lieutenant, U.S. Navy, Judge Advocate General's Corps (1990 – 1994).  Successfully defended Navy, Marine Corps, and Coast Guard servicemen against charges including government contract procurement fraud, conspiracy, espionage, and attempted murder. Received Navy Commendation Medal for distinguished service as defense counsel and Defense Department Head, Navy Legal Service Command Northwest.

  • Martindale-Hubbell A/V rating; 10.0 Avvo rating; named Rising Star ® (2005, 2006) and Super Lawyer ® (2007 – 2019) by Thomson Reuters.    

Civic Activities:

Board of Directors, Audubon Action Fund (501(c)(4)) (2018 - present)

Board of Directors, Pacific Public Media (KNKX-FM) (2016 – present; Chair, 2016 – 2019)

Board of Directors, National Audubon Society (2014 – present; Chair, Environmental Litigation Committee, 2014 – present)

Board of Directors, Braided River Publishing (2014 – present; President, 2016 – 2018)

Board of Trustees, PCC Community Markets (2006 – 2015, 2017 – present; Chair, 2008 – 2010)

Advisory Board, Cascade Public Media (KCTS 9 Public Television) (2013 – 2017)

Board of Directors, Washington Trails Association (2008 – 2017; President, 2014 – 2016)

Advisory Council, KPLU-FM (2013 – 2016; Chair, 2013 – 2016)

Board of Directors, Salish Sea Expeditions (2000 – 2005; President, 2001 – 2004)

Board of Trustees, Academy of Music Northwest (1997 – 2001)

Volunteer Instructor, Youth Education Program, The Nature Conservancy (1993 – 1995)

Volunteer, Recreational Therapy Department, Seattle Children's Hospital (1991 – 1993)

Select Publications and Presentations:

Guest, Green Dreamer podcast, discussing the intersection of environmental and public health (September 19, 2019)

Speaker, "Introduction to the Endangered Species Act," 26th Annual ESA Conference, Seattle, Washington (January 24, 2019)

Speaker, "'No Reasonable Expectation of Success': Faith as the Keystone of Climate Justice," Edmonds Unitarian Universalist Congregation, Edmonds, Washington (April 24, 2016)

Co-author (with B. Epley), "Much Ado About Something: The First Amendment and Mandatory Labeling of Genetically Engineered Foods," 89 Washington Law Review 301 (June 2014)

Co-author (with A. Shattles), “Underground Storage Tanks,” Washington Real Property Deskbook (4th Ed., Vol. 7, 2013)

Speaker, "Initiative 522: The Case for Labeling Genetically Engineered Foods," Washington Public Ports Association's Spring Meeting, Stevenson, Washington (May 15, 2013)

Speaker, "Cooperative Growth and a More Impactful Triple Bottom Line," National Cooperative Grocers Association's Leadership Conference, St. Paul, Minnesota (April 14, 2013)

Guest Lecturer, Seattle University School of Law (2012)

Author, "From Fish to Forest," Washington Trails Magazine (September/October 2010)

Author, “Wilderness, Visited,” Washington Trails Magazine (November/December 2009)

Speaker, "Property Rights and Property Wrongs on the American Farm," National Lawyers Guild's Law of the Commons Seminar, Seattle, Washington (March 13, 2009)

Author, "Life in the Margins: A Case for Wilderness on the Farm," PCC Natural Markets Sound Consumer (February 2009)

Author, "Natural Resource Damages," Environmental Compliance Handbook (Association of Washington Business, 5th Ed., 2005)