Salt in your beer is bad enough, but at least it is a choice made by the drinker. (And yes, there really are people who do that.) Sand should not be found in any drink.
Who is the “he” that got sand in your beer? The apparently sentient blob of sand lurking between panels three and four? Who maybe was living in the FIRE sand bucket? And with what reason? He just doesn’t like hearing sand get minimised?
I start to have doubts in panel 4 — since he doesn’t like their tap water, what does he mean about preferring local water? But the real mystery is in panel 5 — have they in some way come into ownership of a spring?