Occurrence and Removal of Chloro-S-Triazines in Water Treatment Plants


Atrazine, simazine, and propazine and their major chlorinated degradates (deethylatrazine, deisopropylatrazine, and didealkylatrazine) are considered as a group to be endocrine-disrupting chemicals by the U.S. Environmental Protection Agency. on this basis, regulatory action levels are currently under consideration for the total chloro-s-triazine (TCT) levels in drinking waters. to assess the concentrations of each of these species in drinking water and their treatability in conventional water treatment, a comprehensive, full-scale study was conducted that included frequent monitoring at 33 and 47 water utilities during 2003 and 2004, respectively. Approximately 900 paired raw and treated water samples were analyzed using a gas chromatography/mass spectrometry method with preconcentration using a mixed-mode, solid-phase extraction that allowed quantitation of each species including didealkylatrazine. the results showed that atrazine concentrations were generally well within the 3 g/L maximum contaminant level (MCL) and that simazine and propazine concentrations were generally negligible. Ninety-fifth-percentile values for the ratio of TCT/atrazine were 4.8 and 4.7, respectively. Effectiveness of conventional treatment technologies, including carbon, was observed to vary significantly. Concerns that didealkyatrazine concentrations may be high and significantly elevate the TCT appear to be unfounded. in general, the results suggest that potential treatment requirements for TCT are not likely to be any more difficult for utilities to meet than the current requirements for atrazine.


Civil, Architectural and Environmental Engineering


AWWA Research Foundation

Keywords and Phrases

Chloro-S-Triazine in Water Treatment Plants; Occurance of Chloro-S-Triazine; Removal of Chloro-S-Triazine; Water Treatment Plants

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Article - Journal

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© 2006 American Chemical Society (ACS), All rights reserved.

Publication Date

01 Jan 2006