Entire house Water Filtration systems are typically the most popular choice as every source of water is purified. Sunlight is limited will remove any contaminants left inside their after the municipal purification process and anything that was picked up as it flowed through your pipes. https://Sd2C-Git.Cores.Utah.edu/hershelmccool3/6984690/wiki/A-Think-About-The-Water-Quality-Test