POU devices in large buildings: Lead removal and water quality

Abstract

The performance of point‐of‐use (POU) devices to remove dissolved and particulate lead (Pb) and their effect on tap water quality were investigated in a large building under typical usage patterns and during one year. Both forms of Pb were efficiently removed, although materials downstream of the POU devices slightly increased total Pb levels at the tap. No evidence of POU breakthrough was observed following stagnations carried out before sampling. Although measurements of heterotrophic place counts and total and live bacteria on the POU material itself indicated no significant colonization, small but significant increases in viable bacteria at the tap suggest that colonization occurred in the piping and tap downstream of the POU devices in the absence of chlorine residual. This study suggests that these devices are a useful remediation approach to control Pb in large buildings, providing that building maintenance procedures are issued for POU devices.

POU water filters effectively reduce lead in drinking water: a demonstration field study in flint, Michigan

“…[64] Using "whole house" or point-of-entry devices for lead removal rather than certified POU devices, can cause problematic water quality changes, including removal of chlorine, that can increase bacteriological risk and increase lead release from premise plumbing after the 'whole house' or point-of-entry filter. [40,[65][66][67] Specific required package labeling and literature, required for certified products, can help the consumer select a product that will meet their needs. For a lead reducing filter, the certification seal and conformance statement on the packaging should indicate that the product was tested and certified against NSF/ANSI Standard 53 and NSF/ANSI Standard 42 for the claims specified on the performance data sheet.…”

“…Deshommes et al (2010) demonstrated consistent lead removal by tap-mounted POU filters (80-99% removal) and under-the-sink POU filters (82-90% removal), which were NSF/ANSI-53-certified for total lead after 2007 and NSF/ ANSI-42-certified for fine particulate (0.5-1 micron), when challenged with two levels of particulate lead (approximately 20 mg L À1 or 100 mg L À1 ) and one level of dissolved lead (approximately 50 mg L À1 ). [39] Based on a combination of understanding of the mechanisms of lead removal within the filters, and some field study evidence, [40] the authors expected that POU filters certified in accordance with NSF/ANSI-53 (total lead removal) and NSF/ANSI 42 (Class I particulate reduction, 0.5-1 micron) standards would be effective at providing protection against lead levels much higher than 150 mg L À1 . Figure 2 illustrates the components of the commercial POU faucetmounted filtration devices designed to remove particulate and soluble metals, including lead.…”

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

“…Of the 11 peer-reviewed studies of inorganic contaminants, one or more of the following elements were studied: Ag, Al, As, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sb, and Zn. Four of the 11 inorganic studies evaluated POU performance for Pb either alone or in conjunction with other metals [11][12][13][14] and 2 for Cu. 11,14 Overall, faucet-mount or under-sink solid block activated carbon (SBAC) filters removed 80% to 99% of total Pb in 2 studies 12,14 and 68% to 98% of total Cu in 1 study.…”

“…Four of the 11 inorganic studies evaluated POU performance for Pb either alone or in conjunction with other metals [11][12][13][14] and 2 for Cu. 11,14 Overall, faucet-mount or under-sink solid block activated carbon (SBAC) filters removed 80% to 99% of total Pb in 2 studies 12,14 and 68% to 98% of total Cu in 1 study. 12 The study by Deshommes et al included laboratory tests of 3 SBAC faucet-mount or under-sink filtration units as well as 1 pourthrough pitcher.…”

“…Similarly, the in-use study with more than 90 observations made in a penitentiary also showed the effectiveness of SBAC filters on both dissolved and particulate lead. 14 In addition, one study evaluated SBAC performance for Mn reduction and found SBAC systems to be effective only up to approximately 50% of filter capacity, but filters containing cation exchange resin were effective in removing Mn at 60 to >99%. 15 No corresponding NSF standard is applicable for Mn reductions, so consumers concerned about Mn in drinking water would not be able to identify a filter to address this metal.…”