Mark C. Piontek represents a broad range of clients including municipalities, public water supply districts, water and sewer authorities, wholesale water commissions, manufacturers, and small business owners in a variety of transactions including real estate, governmental regulations, commercial transactions, and commercial litigation. Mark successfully handles negotiations, litigation, and meditation.

A member of the Missouri Bar, Mark practices before the U.S. District Court in the Eastern District of Missouri. He has successfully argued before the Missouri Appellate Courts in both the Eastern and Western Districts and before the Missouri Supreme Court.

Mark is involved in the community, having served as an advisory board member of a local banking institution, a member of the Franklin County Constitution (which was charged with drafting a charter for Franklin County government), St. Francis Borgia Regional High School Athletic Association, Washington Lodge No. 1559 B.P.O Elks, Washington Rotary Club, Knights of Columbus Seisl Council 1121, Washington Jaycees, and Franklin County Country Club.

Practice Areas


  • Washington University in St. Louis School of Law (J.D., 1986)
  • Saint Louis University (B.S.B.A., cum laude, 1983)

Legal Background

  • City attorney, Marthasville, MO
  • City counselor, Washington, MO
  • City attorney, Washington, MO
  • City attorney, Augusta, MO
  • Sole practitioner (1991-1994)
  • Dempsey, Williams and Piontek, P.C. (1988-1990)
  • Briegel, Dempsey, Baylard and Patane, P.C. (1986-1988)

Professional Affiliations

  • Missouri Rural Water Association
  • International Municipal Lawyers Association
  • Twentieth Judicial Circuit Bar Association
  • Missouri Municipal Attorneys Association
  • Bar Association of Metropolitan St. Louis


  • U.S. Supreme Court
  • U.S. District Court, Eastern District of Missouri
  • Missouri Bar

Charitable & Civic Activities

  • Franklin County Constitution Commission (2008-2009)
  • Knights of Columbus Seisl Council 1121
  • Washington Lodge No. 1559 B.P.O. Elks
  • Washington Rotary Club
  • Franklin County Country Club