AWWA WQTC65804

Lead exposure at the tap is caused by dissolved and particulate lead. The concentration ofdissolved and particulate lead at the tap is directly influenced by the conditions of sampling.Debris trapped by aerators can contain lead particulates from lead pipe surfaces and corrodedsolder. The relative influence of flow rate and the presence of aerators are not clearly understood,but under certain circumstances, reducing the flow rate during sampling and removing theaerator may reduce particulate lead in tap water samples. The impact of the sampling flow rate,flushing and the faucet aerator on dissolved and particulate lead concentrations was investigated.Using a profile sampling approach, the concentration of particulate and dissolved lead wasmeasured as a function of flushing time and volumes. Elevated particulate lead was present onlyin some of the first draw samples taken with an aerator in place which corresponds to the waterin the interior plumbing. No simple correlation was found between lead concentrations and flowrate. Stagnation time of 30 minutes in lead pipes had a significant impact on the leadconcentration in the first draw and flowing tap water samples. Includes 7 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2007

Number of Pages:

9

File Size:

1 file , 56 KB