Water is the main source of life. Living organism can die without water; therefore, human being need water. Clean water is needed to do our daily activities, such as drinking, taking a bath, washing, etc. Clean water is determined from its color, smell and taste. In Jakart, nowadays clean water is hard to be found and its condition is also become worse because the water is polluted. Data from theoffice managing environment in Jakarta said that the rate of water pollution in Jakarta has reached 50 percent, even in some areas the rate of water pollution has reached 90 percent. This water pollution is caused by three main aspect which cause different effect.There are also several solutions to solve this problem.

First, the main cause of water pollution in Jakarta is home sewage. It reaches 60 percent from the total amount of sewage in the river (Kompas 2007). The form of home sewages is not only solid such as garbage and feces excretion, but also liquid such as water contaminated by soap. The accumulation of home sewage disposal can cause several different effects. For example, if someone consumes water polluted by feces excretion, he/she will suffer from many kinds of diseases like diarrhea, cholera, and itchy. Another effect is eutrophycation which is caused by water contaminated by soap. Eutrophycation can disturb the water ecosystem balance. The last effect is flood. Garbage which is thrown away continuously can cause flood in rainy season.

Second, water pollution is also caused by factory sewage. The data of WALHI Jakarta said that only 10 percent industry is manufacturing sewage and concerning about the environmental problem. Although the quantities of industrial sewage disposal is less than home sewage disposal, but the effect of industrial sewage disposal is more dangerous. It is because industrial sewage contains chemical substance and heavy metal like mercury, lead, cyanide ammonia and so on. These substances not only can damage water ecosystem but also dangerous for people because they can accumulate and become toxic in our body, for example the case of Minamata disease in Japan in 1956. At that time water at Minamata bay is polluted by mercury coming from sewage disposal. If adult consumes this polluted water, they will suffer chronic damage of kidney and in kids can cause pink disease, skin allergy and Kawasaki disease.

Finally, another cause of water pollution is farming sewage disposal. The main farming sewage disposal is pesticide and fertilizer. Even though pesticide is used to kill pest, in fact because of the used of pesticide is not appropriate with the regulation, pesticide can be biocide life killer. At the end, the excess used of pesticide contaminating vegetables and fruits can poison the consumer. Sometimes people use fertilizer in large amount, the waste of this fertilizer can trigger the weeds growth which can cause eutrophycation. The used of herbicide to kill weeds can contaminate the ecosystem living in water.

In conclusion, the rate of water pollution in Jakarta increases everyday. This water pollution can cause the lack of clean water for us to use everyday. There are many ways to overcome this problem. First, do not throw away garbage to the river. Second, avoid the excess used of pesticide, third factories should use plasma technology to filtrate factories sewage before dispose to the river.