Our tap water is produced by water treatment plants. It is delivered via water pipes from the water treatment plant to our houses and offices. Along the way, some casualties might happen. For instance, pipe leakage, pipe repair, corrosion of the pipe if it is a metal pipe etc. They may pollute the water again. When the water reaches our houses and offices, it may be contaminated with earth and sand, suspended solids, heavy metal, bacteria and viruses.
To clean the tap water, we need to have it treated one more time.
The recommended method is to use a water filter or water purifier. You may get one in the market.
Posted by Chai Yong of http://www.the-coway.com.