Let's be serious. That is to say, the opinion of "some pilgrims and even a volunteer hospitalero" may have some importance ... and the real absence of mass complaints from citizens of "some cities between Burgos and Leon" has no influence? what are the names of those cities? What are the names of these pilgrims and that hospitalero? Where are the sick?
In a judicial process, abstract accusations are not accepted without well-proven evidence (names, witnesses, signed testimonies, places, times, etc etc.) And here "the problem" is already being treated as if it really exists, based on "some and some" ...
I insist, there is no problem with the water on the meseta. If there were, it would be a huge scandal and the disease would be devastating on the
Camino de Santiago. It is something we would not have heard "some" but all.
Fortunately there are pilgrims with good sense who say they have never had any problems.
Roland49: If you are used to do the standard hygenic precautions (wash hands, rinse vegetables, etc.) than you have done all that you can do to avoid those symptoms. This is pure logic and common sense!
In my opinion, if someone, pilgrim or albergue, has knowledge of several cases of gastroenteritis, they have to notify the health services of Castilla y Leon, they are the first ones interested in discovering the origin of the disease and acting quickly. The health department phone number is 983413600. I know them and I know that they appreciate information of all kinds.