Hearing the word ground water, maybe you will imagine water that is fresh, clear, and worth using. But the fact is that in some areas, especially areas with poor sanitation, ground water is at risk of causing disease because it has been contaminated. Research shows that some areas in Indonesia still have poor groundwater quality. If you think that cooking ground water is enough to be a solution to eliminate contamination, then you are mistaken. Contamination will not disappear just by cooking it. Cooking will only eliminate bacteria and not the contaminants in the ground water. In fact, if you cook it to a boil, pesticides, nitrates, and lead contained therein will still be present. Precisely when the water is cooked, the volume of water will decrease and make the concentration of contaminants will be more concentrated. Dangers of Contaminated Ground Water Clearly water is an important part of daily life. More than half of the composition of the human body consists of water. The