AWWA ACE60028

This slide presentation outlines information on tracking and regulating atrazine occurrence. Project objectives were to: improve the drinking water community's understanding of triazine occurrence patterns in U.S. source waters; short-term variability in atrazine occurrence; support future direction of regulatory programs for triazine compounds in water; and, design of appropriate monitoring programs for compliance and watershed mitigation programs. Topics covered include: utility participation in triazine study; overall sampling program design; information collected along with atrazine monitoring; 2003 atrazine occurrence summary; IMA test procedures used at CU laboratory; atrazine occurrence in raw water supplies; general occurrence trends captured by weekly sampling; importance of seasonality; variability in atrazine found to depend on month of sampling; special focus on 90-day averages; methodology for estimating 90-day averages; maximum 90-day average values for TMP utilities; source water atrazine patterns show difference in variance only; what contributes to atrazine loading; key issues that still need to be addressed; and, approach used to address the key issues.