Unregulated Contaminant Monitoring Rule 4 (UCMR 4)

The final rule "Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) for Public Water Systems" was published in the Federal Register on December 20, 2016. UCMR 4 monitoring will take place from 2018-2020, and includes monitoring for 28 chemicals and two viruses.  Additional information can be found in the UCMR 4 Basic Information Fact Sheet or at EPA's Water: Unregulated Contaminant Monitoring Rule 4 page.

CDX - Link to the Central Data Exchange for water systems (Schedules and Data)

Under UCMR 4, public water systems or EPA will conduct sampling and analysis for Assessment Monitoring for the following:


Haloacetic Acid (HAA)

Additional Contaminants (Metals, Pesticides, Alcohols amd Semivolatile Chemicals)

EPA List of Laboratories Approved for UCMR 4 Analysis - Laboratories that met the approval program application and proficiency testing criteria.