Assessing Water Quality Worldwide
Water pollution and poor water quality of surface waters is something all of us have come to accept as the norm. Rapidly growing populations and the consequent rise in the water demand has created terrific stress on both surface and groundwater systems. Today’s increasing concern is not merely the organic load that gets dumped untreated, or at the most partially treated, into receiving water bodies, but also the discharge of harmful chemicals such as hormone disruptors. What is the status worldwide? Read more
UNEP has brought out a new report titled: A Snapshot of the World’s Water Quality: Towards a global assessment.
Some of the main points summarised in the report are:
People and ecosystems require both an adequate quantity of water as well as an adequate quality of water. Therefore, it is urgent to assess where water quality is inadequate or under threat and to incorporate the need for good water quality into the concept of water security. This report focuses on water quality and its relation to development objectives such as health, food security and water security. To make this connection, the report reviews important water quality problems in surface waters including pathogen pollution, organic pollution, salinity pollution and eutrophication. The focus is on three continents: Latin America, Africa, and Asia.
• Water pollution has worsened since the 1990s in the majority of rivers in Latin America, Africa, and Asia
• Severe pathogen pollution3 already affects around one-third of all river stretches in Latin America, Africa and Asia. The number of rural people at risk to health by coming into contact with polluted surface waters may range into the hundreds of millions on these continents. Among the most vulnerable groups are women and children.
• Severe organic pollution already affects around one out of every seven kilometres of all river stretches in Latin America, Africa and Asia. The high level of organic pollution and its increasing trend is of concern to the state of the freshwater fishery and therefore to food security and livelihoods. Groups affected by organic pollution include poor rural people that rely on freshwater fish as a main source of protein in their diet and low income fishers and workers who rely on the freshwater fishery for their livelihood.
• Severe and moderate salinity pollution already affects around one-tenth of all river stretches in Latin America, Africa and Asia and is of concern because high salinity levels impair the use of river water for irrigation, industry and other uses. Groups affected by salinity pollution include poor farmers that rely on surface waters as a source of irrigation water for their small holdings.
• Anthropogenic loads of nutrients to major lakes are significant and may cause or further advance eutrophication of these lakes. The trends of these loads are different in different parts of the world.
• The immediate cause of increasing water pollution is the growth in wastewater loadings to rivers and lakes. The most important current sources of pollution vary from pollutant to pollutant. Ultimate causes of growing water pollution are population growth, increased economic activity, intensification and expansion of agriculture, and increased sewerage with no or low level of treatment.
• Although water pollution is serious and getting worse in Latin America, Africa, and Asia, the majority of rivers on these three continents are still in good condition, and there are great opportunities for short-cutting further pollution and restoring the rivers that need to be restored.
Actions to be taken to avoid the increase in pollution and restore polluted freshwaters:
1. Monitoring – More understanding is needed about the intensity and scope of the global water quality challenge. For this understanding, it is urgent to expand the monitoring of water quality, especially in developing countries, and especially at the international level through GEMS/Water.
2. Assessments – Comprehensive national and international assessments of the global water quality challenge are needed. These assessments are needed for pointing the way to priority locations and actions for dealing with water pollution.
3. New and old management and technical options – Developing countries have an opportunity to not only employ traditional wastewater treatment, but also to draw on many more new management and technical options for managing water quality including nature-based solutions.
4. Setting up effective institutions – An essential part of managing water quality is setting up institutions that promote action and overcome barriers to controlling water pollution.
In the case of India, the focus has been on the Godavari Basin. The report says that in the Godavari river basin, discharge of untreated and partially treated sewage from cities is one of the principal reasons for the river’s non-compliance with Indian water quality criteria. A Location Importance Index (LII) has been developed to assess the extent and severity of violations of water quality standards. A High LII indicates frequent pollution stress and thus a need for conducting a detailed pollution inventory and expanding water quality monitoring.
UNEP 2016. A Snapshot of the World’s Water Quality: Towards a global assessment. United Nations Environment Programme, Nairobi, Kenya,162pp.