AWWA JAW64970

In this research, experimental tests and practicalcase studies from U.S. utilities uncovered the importanceof chloride-to-sulfate mass ratio (CSMR). When earlyinvestigations of lead contamination in several U.S. citiesfailed to determine the source of the problem, thiswork uncovered the first valid explanation for thosespecific cases by introducing CSMR of water as amajor cause of lead leaching to water.The authors conclusively linked higher CSMR tohigher levels of lead release through galvanic corrosionof lead-tin solder at copper pipe joints. Waterproviders may inadvertently alter the CSMR of theirwater through their coagulant choice. For example,switching from a sulfate-containing coagulant to onecontaining chloride could increase the CSMR, which inturn could trigger lead contamination at levels abovethe regulatory action level. Because even seeminglyinnocuous shifts in water treatment can have unforeseenrepercussions, utilities are advised to undertakepreliminary studies at bench-scale or desktop to helpprevent potential contamination problems in systemswith lead-bearing plumbing. Includes 32 references, tables, figures.

Product Details

Edition:

Vol. 99 - No. 7

Published:

07/01/2007

Number of Pages:

14

File Size:

1 file , 640 KB