Assessing regulatory violations of disinfection by-products in water distribution networks using a non-compliance potential index

Abstract

Inactivating pathogens is essential to eradicate waterborne diseases. However, disinfection forms undesirable disinfection by-products (DBPs) in the presence of natural organic matter. Many regulations and guidelines exist to limit DBP exposure for eliminating possible health impacts such as bladder cancer, reproductive effects, and child development effects. In this paper, an index named non-compliance potential (NCP) index is proposed to evaluate regulatory violations by DBPs. The index can serve to evaluate water quality in distribution networks using the Bayesian Belief Network (BBN). BBN is a graphical model to represent contributing variables and their probabilistic relationships. Total trihalomethanes (TTHM), haloacetic acids (HAA5), and free residual chlorine (FRC) are selected as the variables to predict the NCP index. A methodology has been proposed to implement the index using either monitored data, empirical model results (e.g., multiple linear regression), and disinfectant kinetics through EPANET simulations. The index's usefulness is demonstrated through two case studies on municipal distribution systems using both full-scale monitoring and modeled data. The proposed approach can be implemented for data-sparse conditions, making it especially useful for smaller municipal drinking water systems.

Total fluid consumption and risk of bladder cancer: a meta-analysis with updated data

“…This difference may mainly generate from the evolution in disinfection techniques and regulations. Taking America for example, since the first regulation on disinfection by-products was passed in 1979, chemical substances including trihalomethanes and free residual chlorine have been successively monitored [ 33 ]. Usage of arsenical also keeps declining over the years [ 8 ].…”

Vulnerability Assessment to Trihalomethane Exposure in Water Distribution Systems

“…Other works performed vulnerability analyses to identify the areas of the system and the population with a higher risk respect to DBPs exposure. More recently, Islam et al [34] used a non-compliance potential index predicted using TTHMs, haloacetic acids (HAAs), and free residual chlorine as variables. Successively, Islam et al [35] presented an index-based approach to locate chlorine booster stations in WDSs.…”