The earth boasts an astronomical amount of water—impressively over 1.4 billion km3. In fact, approximately three quarters (70% ) of the earth’s surface is covered in water. This is why many call it the Blue Planet: from outer space, the earth appears completely blue due to all the water that covers it. However, nearly most of this water (97.5%) is saltwater from oceans. Therefore, there is only 2.5% of freshwater, which for the most part is inaccessible because it is trapped in glaciers or deep underground. In fact, less than 1% of the earth’s water is freshwater and accessible for our use and consumption. That’s a very minute amount!
If this amount of water is sustainably used, it can definitely meet the needs of all humans and ecosystems. However, the quantity of water is only one factor in the water issues we face; quality is equally important. It is important to distinguish between freshwater and safe drinking water. While all safe drinking water must be freshwater, the opposite is not necessarily true. Water is considered fit for human consumption when it contains no contaminants or bacteria.
The main sources of water pollution are industry, agriculture and domestic use. Industrial use often causes substantial water quality degradation due to the sheer number of chemicals used; each day, industries dump 300 megatons of toxic waste into waterways. Agriculture does not fare much better with fertilizers, pesticides and animal waste frequently found in lakes, rivers and aquifers. Agricultural nitrates are often the contaminant that is found in groundwater. Domestic waste water is also a major cause of water quality degradation. Despite sophisticated treatment methods and technologies that have been developed over the years, they are far from perfect and not necessarily widely used. Around the world, 80% of wastewater is dumped in waterways without any prior treatment. In developing countries, the amount rises to nearly 90%.
Water pollution is, therefore, a major issue for preserving biodiversity, ecosystems and human health. Contaminated water is the cause of several potentially deadly diseases—with diarrhoea being the most frequent. According to the World Health Organization (WHO), 842,000 people die each year in developing countries due to inadequate access to safe drinking water and sanitation as well as a lack of hygiene. Safe drinking water is vital for the survival and long-term improvement of the living conditions of impoverished populations.
Source: UN Water