Most water used in industrialized countries is treated at water treatment plants. Although the methods those plants use in pretreatment depend on their size and the severity of the contamination, those practices have been standardized to ensure general compliance with national and international regulations. The majority of water is purified after it has been pumped from its natural source or directed via pipelines into holding tanks. After the water has been transported to a central location, the process of purification begins.
Pesticides are often used on farms or garden and run the risk of discharging into water supplies. In the event that there is a well that is contaminated, it has to be tested for pesticide pollution, as only municipal water can be treated. In dealing with pesticides and using home water filtration systems, it may not always prove to be as effective.
Water purification systems that are home-made are not always effective in providing safe drinking water. These systems have to undergo regular maintenance and often have to be replaced in order to effectively filter out all the dangerous organisms and metals.