Sterility isn’t necessary for safe water. You only need it to be pathogen free, and lack dangerous contaminants.

So, beyond that, it kinda depends on what you think “clean” means.

I took a quick gander at how Ireland’s drinking/tap water is regulated.

Assuming whatever location is actually following regulations and standards, y’all got some damn nice water out of the tap. The EU regulations are great. There shouldn’t be anything pathogenic at any concentration to worry about. Since water there is treated, I doubt you’d have much of anything reaching your tap at all. You’d have more particulates than anything else, some trace minerals (which is a good thing), maybe some organics here and there (think bits of algae swept along).

Think about it like aquariums. You don’t want sterility; you want a healthy, flourishing biome because all those bacteria eat bad things.

It’s the same in water pipes; you get a good biofilm growing, and pathogens aren’t going to be able to set up shop, even if they do get past whatever treatment is going on at the source. I’ve even seen arguments against chlorination in water treatment because it’s indiscriminate. It can kill off the friendly stuff and make the system as a whole less resilient to unexpected blooms of something pathogenic.

If you ever set up ponds, you actively encourage bacterial growth as part of the process. There’s aquaculture guides where between the right plants, fish, and bacteria, you can end up with water so clean you’d want to drink it, and can, even starting from sewage contaminated water.

If you then slap a filter on to catch particulates, you’re left with something that’s more pure than if you sterilized the source water by chemical or other means.

Anyway, the EU standards for drinking water are top tier. Go look them up, it’s a really comprehensive and science driven set of standards. If your locale is even half-assing things, you’ve got great water indeed