Kathleen L. Mazure

Of Counsel
  • 1730 Rhode Island Ave, NW, Suite 700
  • Washington, DC 20036
  • 202-289-8450
Having been active in the fields of utility regulation and administrative law for over 30 years, Ms. Mazure has a deep well of hands-on experience providing both strategic advice and legal counsel to a wide range of clients regarding matters before the Federal Energy Regulatory Commission (FERC), state public utility commissions, and federal courts.

Ms. Mazure was in the trenches during the restructuring of both the natural gas pipeline and electric utility industries in the 1980s and 1990s. Ms. Mazure’s degree in economics, with a concentration in regulated industries, affords her a unique ability to analyze complex issues of rate design and allocation, as well as public policy. Those broad experience and knowledge bases allows her to efficiently analyze complex rate, tariff and policy issues, while striving to provide personal attention to achieve each client’s goals.

Ms. Mazure’s experience includes involvement in every facet of utility regulation and administrative law. She has been lead counsel for numerous clients in litigated proceedings involving natural gas pipeline rate, tariff, complaint and certificate proceedings, as well as numerous proceedings regarding electric rates and tariffs, utility mergers, rulemaking proposals, oil pipeline and hydro-electric proceedings. Ms. Mazure coordinates teams including clients, technical and policy consultants, and aligned parties to develop overall case strategies and implements those strategies through review of initial filings or proposals, motions practice, formal and informal discovery, the development of testimony, propounding and replying to discovery, cross-examining and defending witnesses, briefing and appeals of administrative agency decisions.

In addition to litigation and appellate matters, Ms. Mazure regularly advises clients with respect to rulemaking proceedings and policy matters; application of, and proposed revisions to, legislation; rates and operating conditions proposed by Hinshaw and section 311 pipelines; compliance and enforcement matters; transactional matters; matters involving the Public Utility Regulatory Policies Act; and the development of energy projects.

Prior to joining Duncan & Allen in 2018, Ms. Mazure was a shareholder at Duncan, Weinberg, Genzer & Pembroke, PC—a Washington, DC-based law firm that she joined in 2000. From 1989 to 2000, Ms. Mazure was with McCarthy, Sweeney, and Harkaway, PC, a small Washington, DC-based law firm. From 1987-1989, Ms. Mazure was an attorney with the Office of Peoples’ Counsel of the District of Columbia, representing Washington DC ratepayers in both Federal and District of Columbia proceedings. After graduating law school in 1985, Ms. Mazure was a law clerk to three Administrative Law Judges at FERC, experience that provided her a behind the scenes view of how litigated proceedings are analyzed at FERC.

Bar Admissions

  • District of Columbia
  • Maryland
  • Virginia
  • United States Courts of Appeal for the District of Columbia, First, and Eleventh Circuits


  • Marshall-Wythe School of Law, College of William and Mary, J.D. 1985
  • University of Michigan, B.A. Economics 1981 with Class Honors (twice named a James B. Angell Scholar)

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