1. A city water supply is obtained from a deep aquifer. The water has uniform quality. It  is clear and free of organics; hardness is in excess of 500mg/L and consists of both  calcium and magnesium. Dissolved CO2 is approximately 15 mg/L and iron (Fe 2+) is  about 1.0mg/L. Other dissolved constituents are below problem levels. Draw a  schematic diagram of treatment plant that will render this water potable. Identify each  unit and briefly state its purpose. Show points of chemical addition and identify the  chemicals.
2. A large stream flowing through a highly industrialized area must serve as a raw water  supply for a community. The water is consistently turbid, and has refractory organics  that are known precursors of trihalomethanes. Draw a schematic diagram of a treatment  plant that should render this water potable. Identify all units, state their purpose, and  show points of chemical addition. Identify all chemicals.