Minimizing the use of water for processing by reusing and recycling it, is done in two or more successive stages.

• Harvesting of rainwater to meet water requirements.
• Treating hot water and effluents before releasing them into rivers and ponds.

Treatment of industrial effluents can be done in three phases:

• Primary treatment by mechanical means. This involves screening, grinding, flocculation, and sedimentation.
• Secondary treatment by biological process.
• Tertiary treatment by biological, chemical, and physical processes. This involves the recycling of wastewater.