Cascadia Law Group

Environmental Attorneys in Seattle and Olympia

Tanya Barnett

direct: (360) 786-5247

Tanya advises public and private clients on a wide variety of environmental matters, including cleanup of contaminated property, hazardous and solid waste management, wastewater discharge, water rights, and environmental review.  Before joining Cascadia, Tanya spent ten years as an Assistant Attorney General representing the Washington Department of Ecology.


  • Advise clients regarding cleanup of contaminated sites, including negotiation of orders and consent decrees with regulatory agencies.
  • Assist clients with recovery of cleanup costs in contribution claims and allocation proceedings under state and federal laws. 
  • Advise clients regarding compliance with NPDES and state permits for discharge of wastewater and stormwater. 
  • Represent clients involved in other water quality regulatory processes, including development and implementation of Total Maximum Daily Loads (TMDLs) and Section 401 water quality certifications.
  • Advise clients on hazardous waste management requirements under the Resource Conservation and Recovery Act (RCRA) and analogous state law.
  • Advise clients on compliance with solid waste management laws.
  • Represent clients in regulatory enforcement proceedings.
  • Negotiate prospective purchaser agreements with regulatory agencies.
  • Negotiate agreements allocating environmental liabilities.
  • Advise clients on compliance with regulations for PCBs and lead-based paint under the Toxic Substances Control Act (TSCA).
  • Assist clients with changes to and transfers of water rights.
  • Represent clients in disputes over greenhouse gas emissions and climate change.
  • Advise clients regarding compliance with National Environmental Policy Act (NEPA) and State Environmental Policy Act (SEPA).
  • Represent clients in assessment and resolution of claims for natural resources damages.
  • Clients include companies, municipalities and other local governments, nonprofit groups, environmental trusts, and individuals.

Significant Experience:

  • Co-Counsel in Pacific Sound Resources v. BNSF, a Washington Court of Appeals decision that clarified the statute of limitations for contribution claims under the Model Toxics Control Act (MTCA).
  • Co-Counsel in Port of Seattle v. Pollution Control Hearings Board, in which the Washington Supreme Court rejected inappropriate revisions to the Section 401 water quality certification issued for construction and operation of the Third Runway at Sea-Tac Airport.
  • Former lead attorney for the State’s Nuclear Waste Program, which oversees cleanup of the U.S. Department of Energy’s Hanford Site.  Represented Department of Ecology in negotiations for consent decree to settle lawsuit over noncompliance with Hanford Tri-Party Agreement.
  • Co-Counsel in INTERTANKO v. Locke at trial court and U.S. Court of Appeals for the Ninth Circuit, successfully defending state rules governing operations aboard oil tankers.