Potential Effectiveness of Point-of-Use Filtration to Address Risks to Drinking Water in the United States

Abstract

Numerous contemporary incidents demonstrate that conventional control strategies for municipal tap water have limited ability to mitigate exposures to chemicals whose sources are within distribution systems, such as lead, and chemicals that are not removed by standard treatment technologies, such as perfluorooctanoic acid (PFOA)/perfluorooctanesulfonic acid (PFOS). In these situations, point-of-use (POU) controls may be effective in mitigating exposures and managing health risks of chemicals in drinking water, but their potential utility has not been extensively examined. As an initial effort to fill this information gap, we conducted a critical review and analysis of the existing literature and data on the effectiveness of POU drinking water treatment technologies for reducing chemical contaminants commonly found in tap water in the United States. We found that many types of water treatment devices available to consumers in the United States have undergone laboratory testing and often certification for removal of chemical contaminants in tap water, but in most cases their efficacy in actual use has yet to be well characterized. In addition, the few studies of POU devices while “in use” focus on traditional contaminants regulated under the Safe Drinking Water Act, but do not generally consider nontraditional contaminants of concern, such as certain novel human carcinogens, industrial chemicals, pesticides, pharmaceuticals, personal care products, and flame retardants. Nevertheless, the limited information available at present suggests that POU devices can be highly effective when used prophylactically and when deployed in response to contamination incidents. Based on these findings, we identify future areas of research for assessing the ability of POU filters to reduce health-related chemical contaminants distributed through public water systems and private wells.

Influence of Household Water Filters on Bacteria Growth and Trace Metals in Tap Water of Doha, Qatar

“…Although POU/POE treatment devices can contribute to increased water safety and enhancement of water quality, they can have a number of undesirable attributes 6 . They can accumulate sludge, scale, rust, algae or slime deposits in the water distribution systems and potentially represent a temporary reservoir of undesirable contaminants 7 , 8 .…”

Sources of and Solutions to Toxic Metal and Metalloid Contamination in Small Rural Drinking Water Systems: A Rapid Review

“…Numerous methods for treatment were identified in the literature including physical filtration (loose media filters, cartridge filters), chemical filtration (activated carbon, manganese dioxide, activated alumina, granular ferric oxide/hydroxide, other locally produced options), aeration, ion exchange, coagulation, reverse osmosis, distillation, and magnetic purification [ 9 , 16 , 43 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 ]. Each treatment method varies with regards to the TMs it treats, complexity of design, maintenance requirements, and costs.…”

“…While most of the treatments mentioned in the literature have been tested on the laboratory scale or implemented and monitored in larger, professionally managed water utility systems, in many cases the effectiveness and sustainability of treatment technologies in small rural drinking water systems in low- and middle-income countries has not been described [ 54 ]. Still, when determining which treatment to employ for TM contamination, any available evidence on the effectiveness of each treatment method must be considered.…”

“…Still, when determining which treatment to employ for TM contamination, any available evidence on the effectiveness of each treatment method must be considered. Effectiveness of treatment can be an inherent quality of the method, since some methods are more effective than others in treating certain TMs, and can be affected by external factors such as water chemistry; proper installation, operation, and maintenance of the treatment system; and whether the treatment system is used consistently and correctly [ 52 , 54 ]. Appropriate training and community engagement programs can bolster proper setup, maintenance, and use [ 55 , 56 ].…”

“…As a final consideration, treatment methods, especially when poorly designed, maintained, or operated, do not necessarily achieve complete removal of TMs and do not guarantee that concentrations will be reduced below acceptable health guideline values [ 54 , 55 ]. As a result, treatment methods without proper design, maintenance, operation, and ongoing monitoring may provide a false sense of security and should generally be considered only after prevention and other correction measures have been implemented.…”