Karen’s practice focuses on the Clean Water Act and state programs for regulating and permitting water discharges and water supply/use, and on environmental, health, and safety audit review and implementation. 

She has extensive experience assisting industrial and municipal clients in preparing strategies for and pursuing water permits for ongoing operations, expansions and new operations, including permit challenges. Karen also represents clients that must defend CWA and state water law enforcement actions, including claims pursued by governmental as well as third party entities. She recently led a multi-year, complex negotiation of a consent decree for the San Antonio Water System, which was targeted for sewer overflow reductions under EPA's national "wet weather" enforcement initiative. Karen advises clients on business strategies related to increasing water scarcity, and counsels clients on emerging trends in water quality programs, including initiatives such as watershed-based permitting, TMDLs, trading and allocation, and land-based impacts on coastal and ocean resources. She also has extensive experience assisting clients with conducting compliance audits and managing related disclosures, and with developing and implementing management systems for environmental compliance.

Karen also has extensive experience assisting multinational companies manage their global EHS issue portfolios. She helps clients strategically plan and manage both comprehensive and targeted EHS compliance audits, and related federal and state disclosure and corrective action strategies. Karen also has helped companies develop and implement management systems for environmental compliance, sometimes in the context of resolving a major enforcement action. Karen also teams with white collar lawyers to conduct internal investigations and assist in defending civil and criminal investigations. 

In addition to serving as a frequent speaker, writer and planner for a variety of environmental law and policy programs, Ms. Hansen has served in elected and appointed roles on numerous state bar and American Bar Association committees and task forces. Ms. Hansen has served on the firm's Management Committee, Co-Chairs the Water Law Practice, and was the firm’s inaugural Chair of B&D’s Diversity & Inclusion Committee.


  • Trinity University  (B.A., cum laude)
    • Business and Economics
  • University of Texas - Austin  (J.D.)
    • Editor-in-Chief, The Review of Litigation
  • Georgetown University
    • Certificates in Executive and Transformational Leadership

Bar Admissions

  • Texas
  • District of Columbia
  • Minnesota

Professional Affiliations

  • American Bar Association