Early Warning Systems for drinking water sources - Assessment of available and innovative monitoring techniques

The water sources used for drinking water production in the Netherlands have been under increasing pressure in the last decades due to e.g. climate change, the emergence of new contaminants, intensifying subsurface use and population growth. Therefore, Early Warning Systems (EWS) are increasingly seen as an essential addition to conventional monitoring systems. EWS are being widely used to detect irregularities in natural/ human induced processes and to inform users about pending threats (e.g. wildland fires, earthquakes, hydro-meteorological hazards, epidemics and food security). For protecting sources of drinking water an EWS consists of a monitoring approach enabling the early detection of potential threats to drinking water production, which could ultimately affect drinking water safety.
The goal of this research is to determine how current monitoring approaches can be improved to fulfil the requirements of an EWS mentioned above and to investigate if additional (innovative) monitoring techniques exist which can be deployed in an early warning perspective. The main objectives of this research are therefore to: – Identify current monitoring strategies and techniques, through a literature review and a questionnaire which was submitted to representatives of the Dutch drinking water companies. – Determine how these techniques can contribute to an EWS as defined in the context of this research.
– Determine how EWS can contribute to secure long-term drinking water quality in the Netherlands – Find available innovative techniques for monitoring and assess relevance for the Dutch drinking water companies – Test two selected techniques for two suitable drinking water production sites, one groundwater and one surface-water.

Om de drinkwaterkwaliteit te beschermen is het nodig de kwaliteit van de bronnen (grond- en oppervlaktewater) in de gaten te houden, bijvoorbeeld met Early Warning Systemen (EWS). Er is een uitgebreid overzicht gemaakt van bestaande en innovatieve monitoringstechnieken die mogelijk kunnen worden gebruikt voor vernieuwende vormen van monitoring. Bio-assays, spectroscopische technieken (NIR/UV-VIS) en passive samplers komen naar voren als monitoringstechnieken met de meeste potentie voor toepassing in early warning. Drinkwaterbedrijven kunnen met de informatie in dit rapport bepalen in hoeverre zij hun monitoring en early warning van zowel grond- als oppervlaktewater kunnen verbeteren. Het overzicht is gebaseerd op een literatuurstudie en op informatie verstrekt door de drinkwaterbedrijven over de huidige stand van zaken rond monitoring. Het beschrijft het concept early warning en benoemt de eisen waaraan EWS moeten voldoen aan de hand van de gevaren voor grond- en oppervlaktewater. Lopend vervolgonderzoek richt zich op de effectiviteit van enkele van deze monitoringstechnieken.