recycling rain water

The given flow chart illustrates process of recycling storm water for daily using in an Australian city. In general, the process includes 5 steps, beginning with collecting storm water in rainy day and ending with reusing water in sunny day.
Initially, rain water is collected using a system of drains and then run through a series of underground pipes to the water recycling plant. In this plant, water is processed to fit the safe consumption by removing impunities in 4 stages. First, the huge impunities namely rubbish and plastic are removed, followed by small particles , then bacteria and viruses and end up with molecules and salt removal. In the next stage, chlorine is added into the processed water with the rate of 4mg per liter. After that, the water is stored in a water storage before transported by a system of pipes to the place that reuse this water