If you get your water from the city water main, you probably know that it goes through a treatment plant before it reaches your home. All kinds of harmful elements and germs can be found in natural water, which is what the treatment plant is there to remove. Now, some cities are better about removing contaminants than others. No city, though, can completely remove all potentially harmful materials from its water supply. There is always a chance that some trace particles will escape the treatment process, and end up in your home.
If you really want to protect your water supply from these kinds of contaminants, the best thing to do is to install a water treatment system. Some plumbing systems need whole house water treatment systems more than others, especially if they are experiencing symptoms like those listed below.