World Water Day, on 22 March every year, is about taking action to tackle the water crisis. Today, there are over 663 million people living without a safe water supply close to home, spending countless hours queuing or trekking to distant sources, and coping with the health impacts of using contaminated water. This year's theme: Why waste water? in support of SDG 6.3 on improving water quality and reducing, treating and reusing wastewater.
Globally, the vast majority of all the wastewater from our homes, cities, industry and agriculture flows back to nature without being treated or reused – polluting drinking and bathing and irrigation and losing valuable nutrients and other recoverable materials.
Reducing and safely treating and reusing wastewater, for example in agriculture and aquaculture, protects worker, farmers and consumers promotes food security, health and wellbeing.- source-http://www.who.int/