Use the steps discussed in the notes $($i$.$e$.$ Draw the diagram, write the balances, etc.$).$Use engineering problem solving method. A textile plant discharges a waste that contains $20\%$ dye from vats. The color intensity is too great, and the state has told the plant manager to reduce the color in the discharge. The plant chemist tells the manager that color would not be a problem if they could have no more than $8\%$ dye in the wastewater. The plant manager decides that the least expensive way of doing this is to dilute the $20\%$ waste stream with drinking water so as to produce an $8\%$ dye waste. The $20\%$ dye wastewater flow is $900$ gal$/$min$.$ How much drinking water is necessary for the dilution?