Laboratory Approval Program for the Unregulated Contaminant Monitoring Rule (UCMR 6)

• Basic information about the UCMR 6 laboratory approval program
• Step-by-step laboratory approval process
• Maintaining laboratory approval

Basic information about the UCMR 6 laboratory approval program

The “UCMR 6 laboratory approval program” applies to all laboratories that wish to analyze samples for the sixth Unregulated Contaminant Monitoring Rule (UCMR 6). Laboratories are encouraged to apply for method-specific UCMR 6 approval as early as possible, as public water systems that collect samples in the first year of monitoring will make arrangements for sample analysis in 2027, as proposed. Laboratories that successfully complete a registration, the application process, and proficiency testing will receive approval from the EPA once UCMR 6 has been finalized. See the discussion of the step-by-step process below for the proposed deadlines.

Laboratories interesting in competing in the EPA's contract procurement process to support analysis of UCMR 6 samples from small public water systems (those serving 10,000 or fewer people) are encouraged to apply as early as possible.

The list of approved UCMR 6 laboratories will be available after publication of the final rule.

The laboratory approval program is designed to assess whether laboratories meet the requirements described under UCMR 6 for:

• Equipment
• Laboratory performance
• Data reporting

Step-by-step laboratory approval process

Applicants already certified for UCMR 6 methods by their state or EPA Region to conduct drinking water analyses still need to complete the EPA's UCMR 6 approval steps, including registration, the application process, and proficiency testing. To participate in the UCMR 6 laboratory approval program, the laboratory must register and complete the necessary application materials by August 1, 2027. The steps for the laboratory approval process are:

1. Request to participate
Laboratories interested in the program first email UCMR_Lab_Approval@epa.gov and request registration materials.

2. Registration
Laboratory applicants provide the following registration information: laboratory name, mailing address, shipping address, contact name, phone number, email address, and a list of the UCMR 6 methods for which the laboratory is seeking approval. This registration step provides the EPA with the necessary contact information and ensures that each laboratory receives a customized application package.

3. Application package
Laboratory applicants will complete and return a customized application package that includes the following: initial demonstration of capability (IDC) data, including precision, accuracy, and results of minimum reporting level (MRL) studies; information regarding analytical equipment and other materials; proof of current drinking water laboratory certification (for select compliance monitoring methods); method specific standard operating procedures; and example chromatograms for each method under review. Based on the proposed start for UCMR 6 sample collection of January 1, 2028, the EPA expects that the final opportunity for a laboratory to complete and submit the necessary registration and application information will be August 1, 2027.

4. EPA’s review of application package
The EPA will review the application packages and, if necessary, request follow-up information. Laboratories that successfully complete the application process become eligible to participate in the UCMR 6 proficiency testing studies.

5. Proficiency testing
A proficiency test sample is a synthetic sample containing a concentration of an analyte or mixture of analytes that is known to the EPA, but unknown to the laboratory. To be approved, a laboratory must meet specific acceptance criteria for the analysis of a UCMR 6 proficiency test sample for each analyte in each method, for which the laboratory is seeking approval. The EPA anticipates offering up to three of these studies prior to the publication of the final rule, and at least two studies after publication of the final rule. This allows laboratories to complete their portion of the approval process prior to publication of the final rule, and receive their approval immediately following publication of the final rule. 

Interested laboratories must pass a proficiency test and report data for every analyte in the method to be approved for that method, and may participate in multiple studies in order to produce passing results for each analyte. The EPA does not expect to conduct additional proficiency testing after the start of PWS monitoring; however, laboratory audits will likely be ongoing throughout the implementation of UCMR 6.

As a condition of receiving approval, the laboratory must promptly post proficiency test and quality control data that meet method criteria to the EPA's Central Data Exchange (CDX) UCMR electronic data reporting system, the Safe Drinking Water Accession and Review System (SDWARS 6).

6. Written EPA approval
After a laboratory successfully completes steps 1 through 5, the EPA will send a letter listing the methods for which the laboratory is approved.

Maintaining laboratory approval

Approved laboratories must adhere to the quality assurance and quality control procedures and criteria outlined in the method(s) and rule language to maintain their approval status.

Under UCMR 6, as proposed, laboratories would be required to post sample data and required quality control data electronically via SDWARS 6 within 90 days of the sample collection date.

Once a laboratory is disapproved, the EPA does not anticipate any opportunity for reinstatement during the UCMR 6 monitoring period. Approved laboratories are subject to on-site laboratory and/or off-site (paper) audits.