By Rick Andrew

Lead in drinking water continues to be a major concern for the general public, especially those served by public water supplies with aging infrastructure. There are several ongoing initiatives to investigate potential lead contamination in these areas, some with focus on the impacts of lead service lines and specific practices of water treatment, seeking data on the amount and form of lead that could potentially be leaching into the water.

As efforts to better understand the nature and the extent of potential lead contamination of drinking water continue, there is also focus on reducing regulatory levels for lead in drinking water. Several states are seeking to reduce regulatory levels for lead in drinking water to five μg/L. Canada has implemented new Guidelines for Canadian Drinking Water Quality for lead at five μg/L and the EU is actively working to revise their acceptable level for lead in drinking water to five μg/L as well.

NSF/ANSI DWTU Joint Committee Activities
At the May 2018 meeting of the NSF Joint Committee on Drinking Water Treatment Units, in keeping with these developments regarding lead in drinking water, a proposal was made to create a task force to assess the impact of revising the pass/fail criteria for lead reduction in NSF/ANSI 53 from 10 μg/L to five μg/L in the effluent (filtered) water. The proposal requested that the task force focus on four specific activities:

  1. Making a request to the accredited certification bodies to review the impacts to certified products that would occur. In other words, would there be products that would need to be retested or potentially lose certification due to not meeting the five-μg/L criteria, and if so, how many?
  2. Examining and considering the appropriateness of maintaining the current challenge requirements as the change is made. Should the challenge continue to be 150 μg/L lead, with 30 percent of the lead in particulate form for the pH 8.5 test?
  3. Developing a recommendation for timing of the change. Is this something that can be done quickly or are there reasons to delay such a change?
  4. Identify any other consequences of making such a change. Would there be other impacts beyond examining current certifications and the composition of the test water?

The proposal was accepted by the joint committee and the task force was formed.

Results of work by the task force
The task force recommended adding an informational annex to NSF/ANSI 53 for the 2018 version, providing background and additional relevant information regarding lead and the proposed changes to the standard. Annex M was added to NSF/ANSI 53-2018 to raise awareness of the issue and to let users of the standard know that the joint committee intended to change the pass/fail criteria for lead reduction from 10 μg/L to five μg/L in NSF/ANSI 53 in 2019.

Additionally, the task group worked with accredited certification bodies to review the potential impacts to certified products. The review involved examining test reports supporting certifications to see how many lead levels in effluent samples (filtered water samples) were between six μg/L and 10 μg/L, versus those test reports in which all of the effluent samples were five μg/L and below. Any certifications supported by test reports that included all lead levels in effluent samples at five μg/L and below would be unimpacted by the proposed change. Any test reports with effluent levels between six μg/L and 10 μg/L would indicate a need for retesting and, potentially, a risk of loss of certification. With these implications in mind, the review was completed and it concluded that certified products demonstrate the ability to reduce lead concentrations to a level at or below five μg/L.

The task group further recommended no other changes to the current challenge requirements, including maintaining the challenge requirement of 150 μg/L lead, with 30 percent of the lead in particulate form for the pH 8.5 test. Based on the conclusion of the review of potential impacts to certified products and because no other changes to the current challenge requirements were recommended, the task group concluded that there wouldn’t be any other consequences or impacts resulting from changing the standard, and that the changes should be made sooner rather than later.

Changes on the way
Once the task group had finished its work and shared recommendations with the joint committee, the changes were officially balloted through the joint committee in March, 2019. These changes will be combined with other changes to NSF/ANSI 53 balloted in 2019 and ultimately published in NSF/ANSI 53-2019. Although making these changes to the standard did not impact existing certifications, they are nonetheless very important.

First, the changes assure that any products certified for lead reduction in the future will be capable of reducing lead to five μg/L or below when tested in accordance with the protocols in NSF/ANSI 53. Second, the changes reinforce the message to end users that the standard is very rigorous, requiring reduction of lead to a level below the current US EPA Action Level and consistent with new, more conservative levels being developed in multiple areas. Third, the joint committee is assuring that NSF/ANSI 53 is up-to-date with the latest trends in the regulatory community, maintaining the standard’s relevance as a globally recognized resource for evaluating the quality and performance of filtration technologies.

About the author
Rick Andrew is NSF’s Director of Global Business Development–Water Systems. Previously, he served as General Manager of NSF’s Drinking Water Treatment Units (POU/POE), ERS (Protocols) and Biosafety Cabinetry Programs. Andrew has a Bachelor’s Degree in chemistry and an MBA from the University of Michigan. He can be reached at (800) NSF-MARK or email: [email protected]


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