Modeling the Formation and Propagation of 2,4,6-trichloroanisole, a Dominant Taste and Odor Compound, in Water Distribution Systems

Flexible decision-making framework for developing operation protocol for water distribution systems

Past water distribution systems (WDS) management studies derived operation protocols to maximize WDS reliability by using residual chlorine as the sole surrogate parameter for water quality reliability. Albeit the advancement in mechanistic modeling to examine the WDS water quality, emerging water quality parameters of concern are not yet involved in solving WDS management problems. This paper attempts to overcome this limitation by developing a flexible decision-making framework -integrating EPANET-C, a mechanistic modeling tool for WDS water quality, with Analytic Hierarchy Process (AHP), a multi-criteria decision-making method - to rank the possible water quality parameter-based operating alternatives (organic matter and residual chlorine levels at the source points) for WDS. The uncertainty analysis was incorporated into the mechanistic modeling using the Monte Carlo method to realize insufficient knowledge about the complex biological and physicochemical interactions inside WDS. Six cases, each ranking the alternatives diversely, were applied to reflect the expert judgment impressions on the AHP outcomes. The consistency of the proposed decision-making framework was verified by deriving the operation protocol for two test networks by making trade-offs between the multiple and conflicting microbiological, chemical, and organoleptic quality criteria. The disinfection by-products formation control and taste and odor problems control emerged as the most critical water quality criteria determining the WDS performance under the operating alternatives examined. Altogether, the obtained results suggested the practicality of adopting a flexible operation protocol to maintain the water quality benchmarks over various plausible WDS performance scenarios, ranging from worst to best.

Contaminant Fate and Transport Modeling in Distribution Systems: EPANET-C

Typically, computer-based tools built on mathematical models define the time-series behavior of contaminants, in dissolved or colloidal form, within the spatial boundaries of water distribution systems (WDS). EPANET-MSX has become a standard tool for WDS quality modeling due to its collaboration with EPANET. The critical challenges in applying EPANET-MSX include conceptualizing the exchanges among multiple reacting constituents within the WDS domain and developing the scientific descriptions of these exchanges. Moreover, due to its complicated user interface, the EPANET-MSX application demands programming skills from a software engineering viewpoint. The present study aims to overcome these challenges by developing a novel computer-based tool, EPANET-C. Via built-in and customizable conceptual and mathematical models’ directories, EPANET-C simplifies WDS water quality modeling for users, even those lacking programming expertise. Due to its flexibility, EPANET-C can become a de facto standard tool in WDS quality modeling study both for the industry and the academia.