Applying the LT2ESWTR Microbial Toolbox at a Surface Water Treatment Plant: Fid-Bau Portal

Applying the LT2ESWTR Microbial Toolbox at a Surface Water Treatment Plant

Cornwell, David A. / Brown, Richard A. / Macphee, Michael J. / Wichser, Robert C.

The proposed and final versions of the Long‐Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) have not been published, but water suppliers are already gearing up for the challenges of compliance with the rule. This article discusses LT2ESWTR regulations in terms of their effect and implication for a surface water treatment plant. A case study applied the expected requirements of the LT2ESWTR to the Richmond, Virginia Water Treatment Plant (RWTP). The components of the microbial toolbox were analyzed in terms of cost, feasibility, and applicability to the Richmond facility. For RWPP, the most feasible and cost‐effective toolbox alternatives available were: a 0.5‐log credit for a watershed control program; a 0.5‐log combined filter effluent turbidity credit; a 1.0‐log demonstration of performance credit using full‐scale aerobic spore monitoring or pilot‐scale microbial challenge studies; and, inactivation with ultraviolet light. Although this study is specific to Richmond, the findings can be used by other utilities facing similar situations with similar alternatives available to them resulting from application of the microbial toolbox. This article is not available in its entirety in the printed issue of the Journal; only the expanded summary is available in print. The PDF of the entire article can be found on‐line at www.awwa.org.