Water is a vital element of life and there is no life without water. Life itself over 3 billion years ago miraculously started in the water. When scientists explore the other planets, they are looking for water as without it there would be no life. About 70% of the earth is covered by water and only 2.5% of it is fresh water but only 0.01% is potable. By considering the positive rate of population growth in the world, it can be said that there might not be enough water in the future for human consumption, plants and animals. 31 countries in Asia and Africa are in absolute water shortage and this number will increase to 48 in 2025. Still 2.5 billion people do not have any sewage facility. Over 80% of sickness in developing counties is caused by water pollution. These numbers are indeed shocking but they put more attention to the water issue. When I was a child, I was told that the third World War would be because of the water shortage.
People in big cities with always access to water have taken this essential element of life as granted and maybe that is the reason that even in very developed countries with material recycling rate above 60%, water recycling still has a very small percentage. There have been so many awareness campaigns regards to wiser water consumption around the world but personally I feel, till people do not experience or understand the water shortage they cannot be really wise consumers. The amount of water that we in big cities let it run from our tabs when we wash dishes, shave our face or brush our teeth might be the same amount of water a family use in a village in Africa for a week. The sad point is that the water that is being wasted in our houses has reached there at the first place with difficulties. The water was collected in catchment areas, then it was treated and next through the pipes and pumps which covers the whole city it came to our homes. After usage, through different pipes it would go back to a treatment plant and then released to the river. The fact is that still in many developed countries the same clean water goes to the toilet flush. As both water and wastewater is not cheap, there has been some recommendations and suggestion to reclaim and recycle the wastewater. There are different methods like decentralized treatment plants in building to treat the water not for drinking but for using it in the toilet for flushing. In this short paper, it is tried to discuss the advantaged and disadvantages of water reclamation and reuse.
Reusing wastewater would improve sustainability and secure the water with much less pressure on environmental sources in addition to many economic benefits. If wastewater is treated enough it can be reused for agriculture, landscaping irrigation, industrial processes, toilet flush and cooling water in power plants. The water used for agriculture and landscaping irrigation might not be proper for drinking but according to the United States EPA, there have not been any human health problems due to contact with recycled water that has been treated to the required standards. By reusing treated wastewater, of course the cost will decrease as for the mentioned examples there would not be necessary to treat the water in its highest quality. It is also great method for a country to reduce its carbon footprint as it would need less treatments and transportation of wastewater to the treatment plants. Recycling water is a great method for regions with less annual rainfall as they can conserve more water. In addition to the benefits above, it decreases the use of fresh water which can conserve the balance in ecosystem as well as less water to treat and as a result less water to discharge into the sensitive waters.
However, reusing wastewater is not without risks and it can have negative impacts on human and the environment around it. The most important factor in water reuse is hygiene and as it was mentioned earlier, water is the source of life and that includes life of so many pathogens. Pathogens are the major concerns when it comes to human health. Usually reverse osmosis is a great method as it can remove the chemicals and pathogens from the wastewater and then expose it to UV light or oxidation for disinfection. Nutrients, organics and heavy metals in wastewater are the contaminants that if not properly treated can seriously threat the human’s health and his surrounding ecosystem. Other characteristics of wastewater such as salinity, chloride, nitrogen and phosphorus are other factors than need to be considered for different purposes of water recycling. Usually household wastewater does not contain any heavy metal but the concentration of new types of chemicals like hormones and residue of the contraceptives is increasing in the wastewater and it can also have unknown impacts on the ecosystem. Another problem could be different infrastructure to separate the fresh water from the flush water in a building which would end up in higher costs.
By considering the pros and cons, water reuse would be much better even though in some aspects it might increase the costs. Water is the most important element of life and there would be no life without it. As a result, human has to do anything in its power to keep this valuable resource always available and clean. Wise man said once that we did not inherit the world from our ancestors but borrowed from our children.