Overview of microbial risks in water distribution networks and their health consequences: quantification, modelling, trends, and future implications

Abstract

The water distribution network (WDN) is usually the final physical barrier preventing contamination of the drinking water before it reaches consumers. Because the WDN is at the end of the supply chain, and often with limited online water quality monitoring, the probability of an incident to be detected and remediated in time is low. Microbial risks that can affect the distribution network are: intrusion, cross-connections and backflows, inadequate management of reservoirs, improper main pipe repair and (or) maintenance work, and biofilms. Epidemiological investigations have proven that these risks have been sources of waterborne outbreaks. Increasingly since the 1990s, studies have also indicated that the contribution of these risks to the endemic level of disease is not negligible. To address the increasing health risks associated to WDNs, researchers have developed tools for risk quantification and risk management. This review aims to present the recent advancements in the field involving epidemiological investigations, use of quantitative microbial risk assessment (QMRA) for modelling, risk mitigation, and decision-support. Increasing the awareness of the progress achieved, but also of the limitations and challenges faced, will aid in accelerating the implementation of QMRA tools for WDN risk management and as a decision-support tool.

Advanced Techniques for Monitoring and Management of Urban Water Infrastructures—An Overview

“…A factor that should not be neglected is the transmission of diseases through water, if it does not meet all the conditions related to quality. Thus, a quantitative microbial risk analysis (QMRA) is also needed [168]. For such an analysis, decision makers play an important role in risk mitigation.…”

Health risks due to intrusion into the drinking water distribution network: hydraulic modelling and quantitative microbial risk assessment

“…12,13 Overall, 37% of GII cases in Sweden may be attributed to pathogen intrusion in the WDN, 14 while in the USA and Europe, 30% and 31% were observed, respectively. 15 Previous studies 16 have investigated the association of pathogen intrusion into distribution networks with the endemic level of GII. This includes studies in Canada, Australia, Sweden, the United Kingdom, Norway, and USA.…”

Risk-Based Evaluation of Improvements in Drinking Water Treatment Using Cost-Benefit Analysis

“…Water 2022, 14, 782 2 of 14 Quantitative microbial risk assessment (QMRA) is an established approach to estimate the impact of waterborne diseases [13][14][15]. It is an assessment which combines the information of a pathogen exposure and its health effects to generate a quantitative measure of the risk, generally reported as the probability of infection (P inf ), quality adjusted life years (QALYs), or disability adjusted life years (DALYs) [13,14].…”