AWWA WQTC63961

This paper presents an analysis of nine years of Total Trihalomethane (TTHM) and haloacetic acids (HAA5) data for 76-88 utilitiesin the state of Missouri for the years 1997-2005. Although these results show thatsince 2001, TTHM and HAA5 concentrations have decreased significantly, many plantsare still in violation of the maximum contaminant levels. The month in which themaximum concentration of these disinfection byproducts occurred in the samples variedwidely throughout the year, and from year to year, for most utilities. Small systemscontinue to have greater TTHM and HAA5 concentrations, and to have greater difficultyin achieving regulatory compliance. A majority of both TTHM and HAA5 appear to beformed within the treatment plant, even though significant increases in bothconcentrations are observed in distribution systems. Use of monochloramine indistribution systems was correlated with significantly lower TTHM and HAA5concentrations in large systems, but not for small systems. Higher raw and finished totalorganic carbon concentration both correlated with significantly higher TTHM and HAA5concentrations. Compliance with the enhanced coagulation requirements was observedto be better for large systems (>10k) than for small systems (<10k). For small systems,the utilities in compliance with enhanced coagulation requirements had lower TTHM andHAA5 concentrations than the utilities out of compliance, though a similar trend was notobserved for large systems. Includes 14 references, table, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2006

Number of Pages:

17

File Size:

1 file , 410 KB