Citizen Science and Hardness

What does it mean to involve drinking water customers as researchers for a period of six months?  In this citizen science project of KWR and the water company Brabant Water, customers will, for the first time, participate as ‘temporary water researchers’ in a scientific study on the hardness of their drinking water, in which measurements will be taken several times rather than only once. The research will take place in the Oss region, where a transport pipeline is being replaced and customers will be temporarily supplied with harder water from another production site. Besides knowledge about the change in the water’s hardness, this research will provide new insights into the socio-scientific value and significance of citizen science, and its impact on the perception and behaviour of the participating customers.


A number of years ago Brabant Water announced its intention to close down the Macharen water production company (WPC), on the grounds that its abstraction and treatment were vulnerable and unsustainable over the long term. As a result, the Oss region is now receiving practically all of its drinking water from the Lith and Loosbroek WPCs, and Macharen is only used on a stand-by basis to meet demand peaks. Water softening procedures allow the Lith and Loosbroek WPCs to supply their customers with soft water. Between November 2017 and February 2018, however, the transport pipeline between Loosbroek and Oss will be replaced, so that Oss will for a time again be supplied with harder water from Macharen and Lith. When Macharen is switched off in February, and Loosbroek resumes its supply, the water will again be soft. In order to make these variations in the drinking water’s hardness (with a maximum range between 1.4 and 2.8 mmol) clear to customers, a group of about 100 randomly selected individuals will be invited to measure the hardness of their water themselves between October 2017 and February 2018.

Citizens become ‘temporary water researchers’

Using a drop test, the project’s participants will determine the hardness of their water on three different occasions: before, during and after the work on the transport pipeline. Over the course of the research, the participants will be informed about the data collected and gain greater insight into the composition of the drinking water. At the same time, Brabant Water will (temporarily) have a more refined measurement network and a better understanding of the impact of the measures on the customer at home. In addition, this research will provide new insights into the socio-scientific value and significance of citizen science, and its impact on the perception and behaviour of the participating customers – for example, we’ll study the extent to which they adjust their use of washing products to the changing water quality.

Unique research approach

The value of involving citizens in research is being recognised in more and more fields and institutes, and is reflected in the steady growth in the number of citizen science projects. This form of participation and research is also being experimented with in the water sector, which is in search of new ways of connecting with customers. What’s unique about this project is that customers are being invited to take several measurements over a period of six months. Never before have drinking water customers been involved in this way. Moreover, the project is also special in that the citizens are being personally invited (instead of being recruited via a general call), so that the addresses in the research area can be selected randomly. In this way a diverse group of customers can be reached, and not only the engaged or social-media active ones.

Citizen Science line of research

The ‘Citizen Science and Hardness’ project, together with the ‘Citizen Science and Lead’ project (with Dunea) and the ‘Citizen Science and Lime’ project (with WML), is part of the joint effort on the part of KWR and the drinking water sector to further explore the value and social significance of citizen science in the water sector. This line of research also fits in with KWR’s engagement in The Clean Water Experiment, in which citizen scientists are mapping the quality of Amsterdam’s surface water. The first citizen science project in the Dutch drinking water sector was the ‘Freshness of Water’ pilot project of 2016.