Water never was a problem, until the advent of widespread agriculture, mining, fertilizer use and big industry. Pollution is a real issue nowadays, so far that certain fish are outright toxic, various xenoestrogens mess up your sex hormones and medications are present in tap water. On top of that come heavy metals , bacteria, and of course issues with old pipes. Sounds bad, right? Because it is. I do not want to fearmonger, just bring an often overlooked health concern to mind that fortunately can easily be fixed using a few water filtering tools.
The biggest changes, using filters for your tap water and shower water. Moreover, avoid drinking tap water and buy quality mineral waters, best found in glass bottles. My favourites here are Gerolsteiner, Steinsieker & Nürburg especially regarding their unique mineral content and little contamination. If you drink tap water make sure it is filtered - some use a reverse osmosis system that purifies your water, just make sure to remineralize it in that case.