By Rick Andrew
Certain POU water treatment technologies are designed for use with POU water coolers. When used with coolers, these technologies are treating potable water supplies to help address concerns with taste, odor, appearance or specific contaminants that may be present in the water. Use of this treatment with POU water coolers can add value to the cooler and enhance the experience for end users who drink water from the coolers.
The quality of these technologies can be established through assessment of conformance to certain of the NSF/ANSI Drinking Water Treatment Unit Standards. These standards address multiple aspects of the technologies in terms of their fitness for purpose when used with POU water coolers. By specifying and using technologies that conform to these standards, POU water cooler manufacturers, vendors, renters and users can have a high degree of confidence that use of these technologies will be beneficial.
Each of these standards includes similar requirements, which address safety, structural integrity, contaminant reduction performance, end-user instructions and more. A summary of these requirements is presented in Figure 1. Some of the requirements, such as material safety, structural integrity and end-user instructions, are addressed very similarly and in some cases identically across the various standards. The contaminant reduction performance test methods, however, can vary significantly because the various technologies and contaminants behave differently. For this reason, there are multiple standards that address different technologies and/or contaminants, as opposed to one all-encompassing standard.
Scope and contaminant reduction claims
The scopes of these standards and protocols can generally be described based on technology: mechanical filtration, active media, RO, UV, etc., and on contaminant reduction claims. Basically, different technologies have different capabilities, limitations, operating modes, maintenance requirements and configurations, so it is logical to organize standards according to technologies. That way, the scope of the standard, the contaminant reduction claims available and testing methods are appropriate and applicable to the technology addressed in that particular standard or protocol.
For example, RO systems are constructed and operated very differently from GAC filters, with each having very different water treatment capabilities. Criteria that are important for evaluation of RO systems, such as TDS reduction performance and daily production-rate determination, are not relevant to GAC filters. Similarly, fundamental criteria for evaluation of GAC filters, such as replacement element capacity, are not relevant to RO systems. This leads to the test methods for evaluation of these technologies being very different from each other, with different sampling formats, end points, contaminants and test-water characteristics, allowing for appropriate challenging of their performance.
Taking into consideration the various technologies employed for water treatment in POU water coolers, it becomes more understandable that there multiple NSF/ANSI Standards for evaluating these technologies. Figure 2 provides a summary of the scope and examples of typical contaminant reduction claims available in the NSF/ANSI Standards, relevant to treatment technologies used with POU water coolers.
Establishing a basis for confidence
The NSF/ANSI Standards for treatment technologies used with POU water coolers are very rigorous, scientifically based documents, designed to evaluate multiple aspects of the technologies to help assure they will be safe, structurally sound and will provide effective treatment of the water according to the claims made by the manufacturer.
POU coolers can be appealing to end users because not only do they provide access to cooled and possibly also heated water, but also they include treatment to help assure that the water is the highest quality possible. This treatment is often tailored to the characteristics of the water and the preferences of the end user and can include a wide variety of possible technologies employed. Fortunately, the NSF/ANSI DWTU Standards address each of these technologies very specifically to provide an appropriate and challenging test method to evaluate the contaminant reduction performance.
By using technologies that conform to these standards, end users can rest assured and have confidence that these technologies are safe and effective in treating the water, as claimed by the manufacturer. This confidence adds value to the equation for the manufacturer of both the cooler and the treatment technology, the distributor or cooler rental company and the end users who enjoy the drinking water they obtain.
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