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Monitoring Unregulated Contaminants in Drinking Water

  • EPA collects occurrence data for contaminants that may be present in drinking water, but are not currently subject to EPA drinking water regulations. Learn about the Unregulated Contaminant Monitoring Rule.

Monitoring Unregulated Contaminants in Drinking Water

  • Learn about the Unregulated Contaminant Monitoring Rule (UCMR)
  • Meetings and Materials

Current and Previous UCMRs

  • UCMR 5 (2022-2026)
  • UCMR 4 (2017-2021)
  • UCMR 3 (2012-2016)
  • UCMR 2 (2007-2011)
  • UCMR 1 (2001-2005)
  • UCM-State Rounds 1&2 (1988-1997)

UCMR Laboratory Approval

  • UCMR 5 Laboratory Approval Program
  • EPA Approved Laboratories for UCMR 5
  • EPA Approved Laboratories for UCMR 3 and UCMR 4

Reporting Requirements and Occurrence Data

The Safe Drinking Water Act requires that EPA establish requirements for PWSs to monitor for priority unregulated contaminants every five years and requires EPA to make the results publicly available.
  • Reporting Requirements
  • Occurrence Data

Important Dates for UCMR 5

  • March 2022 – Public webinar on the final Revisions to the Unregulated Contaminant Monitoring Rule for the Fifth Monitoring Cycle (UCMR 5).
  • August 1, 2022 – Deadline for laboratories seeking approval to complete and submit the necessary registration form and application materials.
  • December 31, 2022 – Deadline for large systems to update sampling location(s) and zip code(s). If applicable, the system may update their monitoring schedule; and small systems to update sampling location(s), shipping address, and zip code(s).

Related Information

  • Contaminant Candidate List
  • National Contaminant Occurrence Database
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on December 22, 2022
United States Environmental Protection Agency

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