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NSF/ANSI 61 Evaluation of Lead Pipe. Peter Greiner, NSF Std 61 JC Meeting December 1, 2011. NSF/ANSI 61 Evaluation of Lead Pipe (DWA 61-2011-9). Background
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NSF/ANSI 61 Evaluation of Lead Pipe Peter Greiner, NSF Std 61 JC Meeting December 1, 2011
NSF/ANSI 61 Evaluation of Lead Pipe (DWA 61-2011-9) • Background • Jour. AWWA article published in 2005 that asserted the test waters and normalization criteria are so inadequate in Std 61 that a small pure lead device will pass the standard. • NSF review noted only pH 5 water used with pure lead device allegation. Separately, the portion of the research that did use the pH 10 water aerated it for 1hr prior to use making it unfit as an accurate assessment of the standard. • Allegations about standard referenced in additional Jour. AWWA articles, including Nov. 2010. • Std 61 JC recommended at last meeting that NSF simply perform a study on lead pipe to document how it fairs under the std.
NSF/ANSI 61 Evaluation of Lead Pipe (DWA 61-2011-9) • Pipe materials • 4’ length of ¾” new Pb pipe obtain • Sectioned into 9, 5” lengths with tub cutter • Ends lightly reamed and sections cleaned • Teflon wrapped stoppers affixed to bottom end • Exposure protocol: • Followed the normal 17-day protocol used on pipe for cold water products. • Samples exposed to the normal pH 5 and pH 10 test waters required on pipe (and in-line devices). Additionally exposed to the pH 8 test water. • Analysis: • In addition to required p/f day (17), samples Days 2, 4, 9, and 10. • Repetition: • All exposures performed in triplicate.
NSF/ANSI 61 Evaluation of Lead Pipe (DWA 61-2011-9) Table 3: Lead results from all Day-17 exposures (µg/L)
NSF/ANSI 61 Evaluation of Lead Pipe (DWA 61-2011-9) Results evaluated as pipe
NSF/ANSI 61 Evaluation of Lead Pipe (DWA 61-2011-9) Table 6: Day 17 Normalized Lead Extraction Results (µg/L) Table 7: Day 2 Normalized Lead Extraction Results (µg/L)
NSF/ANSI 61 Evaluation of Lead Pipe (DWA 61-2011-9) • Summary of findings: • Although the results of their pH 5 testing could be normalized to acceptable levels in the hypothetical pure-lead device, would have failed the pH 10 criteria by well over 10x. • If tested using the pH 10 water the hypothetical device volume would need to be < 0.63 mL. • The evaluation performed was immaterial • The comparative test water leach rates from lead pipe don’t match experience with lead from brass. • Pure lead products have never been allowed for use under the standard.
Thanks…! Pete Greiner greinerp@nsf.org 734-769-5517