What chemical is added at the pumping stations at the lakes? What chemicals are added at the plant and explain why each one is used to purify the water. What is the function of the the settling...

What chemical is added at the pumping stations at the lakes? What chemicals are added at the plant and explain why each one is used to purify the water. What is the function of the the settling basins? After leaving the settling  basins  the water flows to the sand filters. Describe the structure of a sand filter. How do they clean a sand filter? After water leaves the sand filters flows to the pumping station and then to large storage tanks. Where are the pumping station and storage tanks located locally? What are the big green tanks around the city used for?