Citizen Science and Lead

In this innovative research project of KWR and the Dunea water company, customers of a water company are taking part for the first time in a scientific study, as researchers, into lead water pipes. Dunea wants to locate the last lead water pipes in its supply area and involve residents of The Hague in the process. Besides supplying information about the presence of lead, the project will provide insight into the socio-scientific value and significance of citizen science.


Some of the houses built before 1960 still have lead water pipes. In a few cases this is because the supply pipes from the street to the house are still partly made of lead but, usually, it’s because the in-house lead water pipes have not yet been replaced. Failures and leakages occur more frequently in lead water pipes and low concentrations of lead can end up in the water. Dunea therefore wants to remove the last residues of lead from its pipe network and, at the same time, raise home owners’ awareness about lead in the home, so that they may take the appropriate measures.

The ‘Citizen Science and Lead’ project helps Dunea and the residents of The Hague in determining those addresses where lead water pipes are possibly still present. This research also allows Dunea and KWR to build up more experience in projects in which professionals carry out research jointly with customers. Citizen science is already common in a many fields, but the experience with it in drinking water research is still relatively limited.

From self-checking, sampling to independent testing

Working with the citizen water-scientists, in this project KWR and Dunea are researching (i) the presence of lead water pipes, and (ii) the effectiveness and significance of various innovative methods of locating these pipes.

In two measurement rounds – one in the spring and the other in the autumn – the 500-plus selected households are invited to participate in the research, which includes three variants:

  • Variant I: The customer takes pictures of the water metre set-up and the drinking water pipes, and answers a couple of questions online (self-check).
  • Variant II: The customer does the variant I self-check and, following instruction, takes two water samples from the tapwater in-house; the lead concentration is then determined in the laboratory.
  • Variant III: The customer does the self-check (variant I), takes the samples that are then sent to the lab (variant II), and tests for the presence of lead using two indicator strips.

In all three variants, we question the participants about their motivation, experiences and views.

The division of the selected households into the three variants is done by lot.

Communication and privacy

An integral component of the project is a transparent feedback of the collected data. All the participants will be kept updated via e-mail. To protect the privacy of the participating households, this feedback will never contain information about individual addresses. Depending on the level of enthusiasm, the project will be concluded with a gathering of participants, KWR researchers and Dunea professionals.


This citizen science research shows that the conduct of joint research with the customer is a valuable and suitable manner of detecting lead in in-house water pipes. A total of more than 100 customers from the selected neighbourhoods responded positively to the invitation to participate in the research. Lead was actually found in the drinking water installations at more than 20 of the participating customers. This was new information for most of the customers. In cases where lead pipes were found, approximately half of the participants concerned indicated that they would probably have them replaced within a year, or that they would ask the proprietor to do so. A majority of the respondents found that participating in the research was instructive and useful. In the case of a plurality of the customers, participation had no effect on their trust in the quality of the tap water. But for a few participants this trust actually decreased after the presence of lead was revealed.

Lastly, the research showed that the indicator strips are not sufficiently reliable to be used instead of lead concentration measurements conducted on the water samples in the laboratory. The strip results did not always agree with those of the lab analyses. In conclusion, it can be said that a combination of a visual inspection, together with the lab analysis of drinking water samples taken at the kitchen tap, provides a good way of demonstrating the presence of a lead supply pipe and/or lead pipes in the drinking water installation.