AWWA WQTC64085

Health Canada has proposed a Corrosion Control Guideline, based on lead, which is undergoingpublic consultation and expected to be finalized in 2007. In Canada, there are no regulations andlittle guidance to address corrosion problems and existing sampling methods are inappropriate fordeveloping corrosion control strategies.In Canada, responsibility for drinking water quality falls primarily under the jurisdiction of theprovinces/territories. Health Canada works in partnership with the provinces/territories to developthe Guidelines for Canadian Drinking Water Quality (Guidelines). The Guidelines establish limitsfor substances at levels found in drinking water known or suspected to be harmful. They arepublished by Health Canada and used by all Canadian jurisdictions to establish their requirementsfor drinking water quality.The effects of corrosion and potential impacts on health are complex and varied. Corrosion is acommon problem in Canadian drinking water distribution systems since many municipalitieshave aged iron pipes, lead service lines, leaded brass fittings/components and lead solder. Leadcorrosion has been documented in a number of Canadian cities where lead levels exceeded thecurrent lead Guideline.The proposed Guideline gives consideration to all materials and corrosion-related contaminants indistribution systems. However, lead is the contaminant with the most significant potential healtheffect and since there is no single, reliable method to measure corrosion in distribution systems,the level of lead at a consumer's tap is the primary focus of the Guideline.The Guideline proposes action levels and a two-tier approach for both residential and nonresidentialbuildings. For residential sites, the first action level is intended to assess the leadcontributed from the home's interior plumbing and the lead service line, by collecting a 1L firstflush sample after 6 hrs of stagnation. The second action level is intended to assess averageexposure to lead and trigger corrosion control measures when the lead Guideline is exceeded. Atsites exceeding the first action level, the system is flushed and a 2L sample collected after 30 minof stagnation. This sampling method is derived from a European Commission study thatconcluded that this was the best approach to identify the source of lead and provide arepresentative average of ingested lead.For non-residential sites, action levels are used to provide information on the source of lead indrinking water systems. The first action level samples are collected after 6 hrs stagnation, thuscapturing the lead contribution from the drinking water fountain, taps or outlet. The second actionlevel is based on the lead Guideline using a fully flushed sample method.Health Canada's proposed Corrosion Control Guideline is expected to help Canadian jurisdictionsdetermine the source of the lead and guide the selection of appropriate corrosion control measuresto reduce lead exposure. Includes 9 references.

Product Details

Edition:

Vol. - No.

Published:

11/01/2006

Number of Pages:

7

File Size:

1 file , 320 KB