Water quality is often extensively measured within the framework of Analysis of Microbial Safety of Drinking Water (Dutch abbreviation: AMVD) and other research. The concentration distribution of microorganisms is highly variable, both in raw and treated water. This variability can have a strong influence on the risk and risk assessment in the AMVD.
Statistical interpretation of the collected data on indicator bacteria indicates that the stochastic modelling of concentrations, as a means of determining the average concentration and variation in the surroundings, is difficult. Sampling methods and volumes (detection limits) differ. In the current situation, an instantaneous sample is usually taken which, using culture methods, is then examined for the presence of indicator organisms.
The objective of this research is the evaluation of other sampling strategies and analytical techniques for application in determining organism concentrations in water.
Alternative measurement strategies in dirty and clean water
The research studies whether measurement programmes (sample volumes, frequencies and time) might not be organised more smartly, for example, by adjusting the measurement programme on the basis of the progressive series of results. These adjustments might be simple (sample volumes, sample moments) or advanced, for example, sampling continuously and cumulatively over time, or instantaneously on an automatic basis, in response to process conditions or other signals. Concretely, we do the following:
- Survey alternative measurement strategies for dirty water. Using simulations, the research studies how the expected results could be interpreted in the framework of quantitative risk analysis compared to ‘traditional’ methods. We select two potentially effective methods and test them in practice for their feasibility and results.
- Survey alternative measurement strategies for clean water, for example, for water quality control. Using simulations, the research studies how the expected results could be interpreted in the framework of quantitative risk analysis compared to ‘traditional’ methods. We select two potentially effective methods and test them in practice for their feasibility and results.
Characterisation of measurement strategies and treatment effectiveness
The results can be used for measurement strategies in planned research into water sources and distribution networks. They also offer possibilities for a better characterisation of water treatment.