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Monitoring Unregulated Drinking Water Contaminants

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

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Basic information about the UCMR 5 laboratory approval program

All laboratories conducting analyses for the Unregulated Contaminant Monitoring Rule (UCMR) must be approved by EPA.

The “UCMR 5 laboratory approval program” only applies to laboratories that wish to analyze samples for the fifth Unregulated Contaminant Monitoring Rule (UCMR 5). Laboratories that successfully complete a registration and application process will receive approval from EPA.

Recognizing that participation in the UCMR Laboratory Approval Program is voluntary, and that the upcoming Federal Register publication represents the official version of the UCMR 5 proposed rule, EPA is now entertaining interest from laboratories that wish to apply early.  Laboratories are encouraged to apply for method-specific UCMR 5 approval as early as possible, as EPA anticipates that public water systems that will collect samples in the first year of monitoring will make arrangements for sample analyses soon after the final rule is published.

The list of approved UCMR 5 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 5 for:

  • Equipment
  • Laboratory performance
  • Data reporting

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Step-by-step laboratory approval process

Applicants already certified for UCMR 5 methods by their state or EPA Region to conduct drinking water analyses still need to complete the UCMR 5 approval steps, including analyzing the UCMR 5 proficiency test (PT) samples. To participate in the UCMR Laboratory Approval Program, the laboratory must register and complete the necessary application materials by August 1, 2022. However, early applications are encouraged. The steps for the laboratory approval process are:

1. Request to participate
Laboratories interested in the UCMR 5 laboratory approval program first email EPA to request registration materials (

2. Registration
Laboratory applicants provide registration information that includes: laboratory name, mailing address, shipping address, contact name, phone number, email address and a list of the UCMR 5 methods, for which the laboratory is seeking approval. This registration step provides EPA with the necessary contact information and ensures that each laboratory receives a customized application package. Based on a January 1, 2023, anticipated start for UCMR 5 sample collection, EPA expects the final opportunity for a laboratory to complete and submit the necessary registration and application information will be August 1, 2022.

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 MRL studies; information regarding analytical equipment and other materials; proof of current drinking water laboratory certification (for select compliance monitoring methods); method specific SOPs; and example chromatograms for each method under review.

As a condition of receiving and maintaining approval, the laboratory will be expected to promptly post UCMR 5 monitoring results and quality control data that meet method criteria (on behalf of its PWS clients) to EPA's UCMR electronic data reporting system, the Safe Drinking Water Accession and Review System (SDWARS).

4. EPA’s review of application package
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 5 PT program.

5. Proficiency testing
A PT sample is a synthetic sample containing a concentration of an analyte or mixture of analytes that is known to EPA, but unknown to the laboratory. To be approved, a laboratory is expected to meet specific acceptance criteria for the analysis of a UCMR 5 PT sample(s) for each analyte in each method, for which the laboratory is seeking approval. 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 laboratory approval process prior to publication of the final rule, and receive their approval immediately following the publication of the final rule.

A laboratory is expected to participate in and report data for at least two PT studies. This allows EPA to collect a robust data set for PT results, and provides laboratories with extra analytical experience using UCMR 5 methods. Laboratories must pass a PT for every analyte in the method to be approved for that method, and may participate in multiple PT studies in order to produce passing results for each analyte. EPA has taken this approach in UCMR 5, recognizing that EPA Method 533 contains 25 analytes. EPA does not expect to conduct additional PT studies after the start of PWS monitoring; however, laboratory audits will likely be ongoing throughout the implementation of UCMR 5. Initial laboratory approval is expected to be contingent on successful completion of PT studies, which includes properly uploading the PT results to SDWARS. Continued laboratory approval is contingent on successful completion of the audit process and satisfactorily meeting all the other stated conditions.

6. Written EPA approval
After a laboratory successfully completes steps 1 through 5, EPA  expects to send the laboratory a notification letter listing the methods for which approval is either “pending” (i.e., pending promulgation of the final rule if the PT studies have been conducted prior to that time), or for which approval is “granted” (if after promulgation of the final rule). Laboratories receiving pending approval are expected to be granted approval without further action following promulgation of the final rule if no changes have been made to the rule that impact the laboratory approval program.

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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 5, as proposed, laboratories would also be required to post sample data and required quality control data electronically via the Safe Drinking Water Accession and Review System (SDWARS) within 90 days of sample collection date.

Once a laboratory is disapproved, EPA does not anticipate any opportunity for reinstatement during the UCMR 5 monitoring period. Approved laboratories are subject to on-site laboratory and/or off-site (paper) audits.

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