Assessing the health consequences of deficiencies in water distribution networks: a basis for future network management
Licentiate thesis, 2018
There are two ways to determine the association between incidents in the network and risk for disease: epidemiological studies and modelling. Epidemiological studies have been used to assess the health outcomes to certain exposures in the network, e.g., maintenance work, low pressure events, among others. Studies have linked substantially outbreaks to causes in the network; however, the association with endemic level of disease in the population has had mixed results. Quantitative microbial risk assessment (QMRA) is one of the best frameworks available to simulate the health risks these incidents have on the population.
In this thesis, the foundations for a distribution network microbial risk management framework is established. This is achieved with a systematic literature review and the development of a conceptual model, specifically for the risk of cross-connections and backflows. The systematic literature review was carried out to assess the level of epidemiological evidence for endemic disease, and evaluate the state-of-the-art of QMRA models. A conceptual model for the specific risk of cross-connections and backflows is presented, testing some scenarios to gain insights for future improvements.
Possible improvements for QMRA models, better input data and combination of modelling and epidemiological studies are discussed. One important limitation that needs to be addressed is the economic aspect of potential mitigation measures for incidents. This aspect, in conjunction with the ones previously mentioned, will be essential to overcome in order to have a functional microbial risk management framework.
Chalmers, Architecture and Civil Engineering, Water Environment Technology
DRICKS - Framework programme for drinking water research at Chalmers
Environmental Health and Occupational Health
Chalmers University of Technology