Jeremy Karpatkin represents technology, consumer products, and mining companies in a wide range of complex litigation and regulatory matters concerning the Clean Water Act, CERCLA, FIFRA, and other environmental laws. Mr. Karpatkin has litigated extensively in federal court and represents clients before state and federal agencies. He also counsels clients on federal and state rulemaking and on regulatory compliance. He has successfully challenged EPA rulemakings in federal court, has defended clients in RCRA citizen suits, and has engaged in successful collaboration with state and federal agencies in environmental rulemaking.

Mr. Karpatkin also has an active constitutional rights pro bono practice. His pro-bono matters include litigating due process claims on behalf of displaced tenants, litigation challenging the termination of the DACA program, litigation challenging voter restrictions in North Carolina, and co-authoring amicus briefs to the US Supreme Court on right to counsel claims and freedom of association claims.

Prior to joining Arnold & Porter, Mr. Karpatkin worked at the United States Department of Energy in a variety of capacities involving the remediation of the DOE nuclear weapons complex. His positions included serving as Senior Policy Advisor to the Assistant Secretary for Environmental Management and Senior Advisor to the Manager of the Rocky Flats facility in Golden, Colorado. Previously, Mr. Karpatkin served as Chief of Staff to US Senator Paul Simon.


  • Mosaic Fertilizer LLC in successful challenge to EPA water quality criteria, resulting in striking of portion of EPA rule as arbitrary and capricious. Florida Wildlife Federation v. Jackson, 853 F. Supp.2d 1138 (N.D. Fla. 2012).
  • Mosaic Fertilizer LLC in developing and implementing strategies for complying with state and federal water quality standards affecting permits, TMDLs and operations. 
  • Fortune 100 company on CERCLA clean-ups of sediment “mega-sites” in New Jersey and New York. Representation includes litigation and all stages of the CERCLA remedial process.
  • Fortune 100 company in Special Master process overseeing remediation of contaminated sites in New Jersey subject to federal court consent order, which includes complying with state requirements, federal consent decree requirements and advising the client on property redevelopment.
  • Reckitt Benckiser LLC in complex challenge to EPA FIFRA action in federal District Court Reckitt Benckiser v. Jackson, 762 F. Supp. 2d 34 (D.D.C. 2011), and the Court of Appeals, Reckitt Benckiser Inc. v. EPA, 613 F.3d 1131 (D.C. Cir. 2010); as well as representing Reckitt Benckiser before EPA in FIFRA administrative proceedings. 

  • Fortune 100 technology company in RCRA citizen-suit involving contaminated site in Maryland.
  • Major oil and gas company on compliance with EPA Greenhouse Gas Reporting Rule.
  • DC area low-income housing group in development of DC regulations providing right to hearing and due process for tenants removed from their homes.


  • JD, University of Denver Sturm College of Law, 2005,

    Order of St. Ives

  • BA, Oberlin College
  • District of Columbia
  • US Court of Appeals for the Eleventh Circuit
  • US District Court, Northern District of Florida
  • US District Court, District of New Jersey
Government & Military Service
  • Senior Advisor, Assistant Secretary for Environmental Management, US Department of Energy

  • Senior Policy Advisor, Office of the Manager, Rocky Flats Field Office, US Department of Energy
  • Chief of Staff, US Senator Paul Simon
  • US District Court, District of Colorado, The Honorable Lewis T. Babcock

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