You could contact Waternet ...
Published by wilko koning, programma-manager at Waternet
You could contact Waternet (Amsterdam) at:
info@hetschonewaterexperiment.nl
They have a citizen-experiment for check on waterquality.
also see : https://vimeo.com/252045424
To give you an idea of the diferent tests. (video with english subs)
The experiements are less about the basic parameters and more about how people experience water, but it shure is worth a look how they do this.
The website is: https://hetschonewaterexperiment.nl/amsterdam/de-experimenten/ (dutch only)