The message
from "Dave Plowman (News)" contains these words:

Almost certainly, but do you really want to drink water that has been
held nice and warm with a selection of dead spiders, flies, bats,
rodents and other loft inhabitants in it?

FFS, how often do people have to be told the tank should have an approved
cover and venting to prevent this?

And how often have you seen a perfectly good cover left hanging off?

--
Skipweasel
Pay no attention to that man behind the curtain.