Whenever water is used, something - heat, suspended materials, or dissolved substances - is added to it. Industrial water emissions arise from treatment of incoming water, sanitary services, boiler operation, housekeeping, heat exchange, unit processes, and roof and yard drainages. The environmental engineer must review the control methods most applicable and economic for each waste water source, and these methods are described. By controlling emissions to the water supplies, some clean-up problems may be prevented. These methods are discussed; they include: waste inventory, raw material changes, process changes, burning, recycling, subsurface disposal, and physical, chemical or biological treatment.
The Industrial Environment - Its Evaluation and Control, NIOSH, Cincinnati, Ohio, Chapter 44