AWWA ACE56324

The Elsinore Valley Municipal Water District, located in Southern California, is in the process of converting its secondary disinfectant from free chlorine to chloramine. This action was prompted by the need to lower the trihalomethane (THM) and haloacetic acid (HAA) levels in the distribution system to comply with the requirements of the Stage 1 of the Disinfectants/Disinfection Byproducts Rule. However, due to concerns over the formation of the newly discovered chloramine byproduct, NDMA, the District conducted a study to evaluate the possible formation of NDMA and other nitrosamines upon chloramination of its three water sources. The benchscale results showed that chloramination of one of the District's sources, a local reservoir with high total organic carbon (TOC) water, results in NDMA formation as high as 17 ng/L. This is just below the current NDMA action level of 20 ng/L adopted by the State of California. Enhanced coagulation was not effective in reducing NDMA precursors. The testing results also showed that seven other nitrosamines analyzed were below their respective reporting limits in the chloraminated waters. Includes 6 references, tables, figure.

Product Details

Edition:

Vol. - No.

Published:

06/16/2002

Number of Pages:

10

File Size:

1 file , 300 KB