AWWA WQTC60735

AWWA WQTC60735 Waiting for Stage 2 D/DBPR Promulgation? What To Do In the Meantime.
Conference Proceeding by American Water Works Association, 11/15/2004

Dimperio, Adrianna; Carter, Jason; Barron, Patty; Cline, Gary; MacPhee, Michael

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This study explains how water utilities don't have to wait for rule promulgation to begin evaluating compliance with thepending Stage 2 Disinfectants/Disinfection Byproduct Rule (Stage 2 D/DBPR). Existinginformation can support compliance projections. In addition, examination of distribution systemoperation and water quality can provide further insight than just disinfection byproduct (DBP)control. A water utility in Birmingham, Alabama combined six years of DBP data, TotalColiform Rule (TCR) data, plant and distribution operation data, and system sampling to buildthe foundation for a comprehensive water quality management strategy.Existing water quality data and tank locations were superimposed on distribution system maps tolocate areas that could harbor high DBP concentrations. Forty sample locations were selectedfrom these areas for two sample events. These locations were selected to match thecharacteristics of eventual Stage 2 D/DBPR sample locations, based on the proposed InitialDistribution System Evaluation (IDSE). In addition, the impact of operation of the utility's fourfiltration plants and 50 storage tanks on water quality was evaluated. Further evaluation of available data revealed plant and distribution operation approaches that,while beneficial hydraulically for system flexibility, resulted in problematic system conditionsfor water quality including widely varying pH and low system turnover.Based on the results of the evaluation, a phased water quality management plan was developedand initiated including changes in operational approach, tank modifications, distribution systemmonitoring, and pilot testing to maximize current treatment and distribution performance. Thisevaluation helped identify and address immediate challenges to water quality as well as select themost appropriate new treatment technologies for Stage 2 D/DBPR compliance well ahead of theregulatory driven schedule. Includes tables, figures.