By Rick Andrew
One of the questions that I am asked from time to time is why there are requirements for claims of reduction of certain contaminants included in the NSF/ANSI DWTU Standards, whereas other contaminants do not have those requirements. This is a simple question with a complex answer that has several possible reasons associated with it. One of the main reasons why certain contaminants are included is because of market demand. If there is no market demand for products that reduce a certain contaminant, then it doesn’t make sense to develop requirements for a claim of reduction of that contaminant. If, however, a particular contaminant is becoming an issue in drinking water, such that consumer preference, regulations or other focus is being put on that contaminant, this potentially creates interest for the NSF Joint Committee on Drinking Water Treatment Units to consider development of requirements for a contaminant reduction claim.
Even when there is market interest, there can be several limitations in the ability of the joint committee to develop a contaminant reduction claim. One of these limitations is lack of a regulatory level. If a specific contaminant does not have regulatory levels for drinking water, it can be difficult to establish an appropriate and defensible maximum allowable product-water concentration. For many years, the joint committee looked to US EPA and Health Canada as (basically) the only sources of regulatory levels, but in recent years they have begun to branch out and consider state regulatory levels for contaminants that are not currently regulated by US EPA or Health Canada. This can be tricky when multiple states or jurisdictions have developed regulatory levels that are different from each other. But this approach does offer an avenue to pursue a reduction claim for contaminants that are not yet regulated in drinking water by US EPA or Health Canada.
Another limitation is effectiveness of treatment. If a given treatment technology is not effective in reducing the contaminant to levels below the regulated level, then there is no point in developing requirements for contaminant reduction. Typically, the joint committee will seek at least some confirmation that treatment technologies are effective before initiating work on requirements for a contaminant reduction claim.
A third limitation is the availability of occurrence data of the contaminant in drinking water. The joint committee attempts to set the concentration of the contaminant in the test-challenge water at the 95th percentile of occurrence (such that 95 percent of impacted users would have the contaminant in their drinking water at the tested concentration) or lower. Typically when a contaminant has been monitored in drinking water for a period of time, there is sufficient occurrence data available to the joint committee to analyze and develop a challenge concentration that they can be confident will protect the vast majority of end users.
A new proposal
A proposal to add a new contaminant reduction claim was put forth at the annual meeting of the joint committee on May 13. This proposal was to consider development of requirements for reduction of 1,2,3-Trichloropropane (1,2,3-TCP) in NSF/ANSI 53 and possibly NSF/ANSI 58.
This proposal stemmed from reports that the state of California would like to move forward with a statewide initiative for use of certified POU/POE systems to help provide compliance with the Safe Drinking Water Act (SDWA) for public water supplies. Currently it is noted that one of the most frequent uses of POU/POE for SDWA compliance for small drinking water systems in California is for treatment of 1,2,3-TCP, but there are no requirements for reduction in the NSF/ANSI DWTU Standards.
Although 1,2,3-TCP is not regulated in drinking water by US EPA, it is a regulated chemical in California, with an established state maximum contaminant level (MCL) in drinking water of five ppt (or five ng/L). This MCL was adopted by the State Water Resources Control Board Division of Drinking Water on July 18, 2017. Quarterly sampling for 1,2,3-TCP in drinking water began in early 2018. It was detected in a number of water supplies, especially in small drinking water systems. This sampling effort plus previous sampling efforts provide occurrence data of 1,2,3-TCP in drinking water.
Focus on POU/POE as a solution
California is looking for an economical solution for these small communities that have detected 1,2,3-TCP in their drinking water and attention has turned to the possibility of using POU/POE products. They cannot, however, be utilized for a statewide program yet because there are no established criteria for these products to claim reduction of 1,2,3-TCP and therefore, there is no certification. Development of requirements for a reduction claim for POU/POE technologies will allow for conformity assessment of these products and for third-party certification. Once that certification can be achieved, regulators will be able to specify the use of certified POU/POE technologies for those end users being served by small water systems that are impacted by 1,2,3-TCP.
Stakeholders cooperating to improve water quality
The NSF Joint Committee is comprised of stakeholders from three main categories: regulators, product users and manufacturers. Each of these groups of stakeholders contributes to the development of the NSF/ANSI Standards by bringing their issues, expertise and concerns regarding the standards to the table and working through a consensus process to develop enhancements and advancements. In the case of 1,2,3-TCP, current end users with certain impacted water supplies have a contamination problem that needs to be solved. Regulators in California have developed a regulatory level that can be used as a defensible basis for a maximum allowable product-water concentration for a contaminant reduction requirement. Manufacturers have technologies currently being manufactured that can be tested to confirm that they meet the requirements, once those requirements are developed. Monitoring initiatives have resulted in the availability of the occurrence of 1,2,3-TCP in the drinking water.
All three groups of stakeholders will work together to develop the requirements and test method that will become part of NSF/ANSI 53 and potentially part of NSF/ANSI 58. This cooperation and collaboration is the key toward advancing the interests of all three groups of stakeholders and ultimately helping to improve public health by providing products that have been tested and certified to an American National Standard for effective reduction of 1,2,3-TCP, in addition to the other requirements of the standards for safety of materials and structural integrity.
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: Andrew@nsf.org