In water treatment plants, we generally follow the sequence - sedimentation → loading → filtration → destruction of harmful germs Why is it necessary to follow this sequence? What would happen if the sequence is not followed?

There are four steps involved in water treatment plants, sedimentation, loading, filtration and destruction of harmful germs. During sedimentation, the heavier insoluble impurities settle down. The suspended impurities are made to settle down faster by the addition of some chemicals like alum. It is called loading. The water is then passed to the filtration tank. Here, water passes through the layers of sand, gravel and charcoal which filter the remaining lighter suspended impurities. After the filtration process, chlorination is done to kill the germs that water may contain. After purification, the safe drinking water is collected in the big storage tank and then it reaches homes through pipes. Thus, water treatment plants use different methods to provide safe drinking water to communities. The various steps are designed scientifically and implemented in a sequence so as to obtain the cleanliest water. These techniques are based on the physical properties of the components such as densities, weight, size, etc. Hence, it is necessary to follow each and every step in the correct sequence. If the sequence is not followed, the purification process will not be completed and the impurities will remain in the water. Hence, we will not be able to get pure and safe drinking water.