Targets & Indicators
Managing wastewater and pollution to protect water quality
In addition to adequate volumes of water, social and economic development is also dependent on good water quality. Human activity is the main cause of pollution that makes water dangerous, expensive or even unusable. There is a need to limit pollution, manage wastewater and protect and improve the quality of water thus enabling needs to be met safely.
The proposed target reflects the growing urgency for effective wastewater management and prevention of water-related pollution. Managing the human and environmental impacts of poor wastewater management and increasing the re-use of wastewater for productive purposes has significant public health, environmental and economic benefits.
The Rio+20 outcome document stressed the need to adopt measures to ‘significantly reduce water pollution and increase water quality, (and) significantly improve wastewater treatment’. The health and poverty reduction benefits are linked to, and significantly enhance and reinforce, those from targets A and B, particularly regarding water quality and reducing waterborne and water-washed diseases.
There is growing recognition that the management of domestic wastewater - especially in the urban setting - is crucial to realize the health and environmental gains possible through providing basic sanitation facilities. Protection of water quality from all sources of untreated wastewater, be they domestic, industrial or agricultural, is a prerequisite for ensuring, sustainable development, poverty alleviation, job creation, human and ecosystem health and people’s well-being. This concern and recognition was very clearly expressed at Rio+20 and requires countries to act.
Indicators are proposed that promote improved wastewater management and pollution prevention by addressing: (i) public health protection (ii) protection of the environment (iii) promote the reuse of wastewater and sludge, (iv) support the multiple opportunities of water, nutrient and energy recovery. It is suggested that the indicators are prioritized to address: a) pollution from urban wastewater that comprises both domestic and industrial components, b) point source pollution from large scale industrial and agricultural activities, and c) diffuse pollution, primarily from agriculture. The indicators are designed to help the progressive realization of improvements and to be appropriate to the local context and to the nature of the receiving waters, while avoiding the creation of perverse incentives or objectives that may not be in the national best interest.
As with the other targets, this target both supports and is supported by the other components of the water goal. For example, it aims to ensure water quality by collecting and treating the pollution arising from sanitation and hygiene, but can only do this if the appropriate governance systems are in place.
Wastewater Facts & Figures
The treatment of wastewater requires significant amounts of energy, and demand for energy to do this is expected to increase globally by 44% between 2006 and 2030 (IEA, 2009), especially in non-OECD countries where wastewater currently receives little or no treatment (Corcoran et al., 2010).
Pollution knows no borders either. Up to 90% of wastewater in developing countries flows untreated into rivers, lakes and highly productive coastal zones, threatening health, food security and access to safe drinking and bathing water.
Over 80% of used water worldwide is not collected or treated (Corcoran et al., 2010).
• Wastewater has been defined as the water discharged from a community after it has been fouled by various uses and containing waste, i.e. liquid or solid matter. It may be a combination of the liquid or water-carried domestic, municipal
and industrial wastes, together with such groundwater, surface water and storm water as may
• Population growth, rapid urbanization, and increasing water supply and sanitation provision will all generate increased problems from wastewater pollution.
• It has been estimated that the total global volume of wastewater produced in 1995 was in excess of 1,500 km3.
• There is the understanding that each litre of wastewater pollutes at least 8 litres of freshwater, so that on this basis some 12,000 km3 of the globe’s water resources is not available for use each year. If this figure keeps pace with population
growth, then with an anticipated population of 9 billion by 2050, the world’s water resources would be reduced by some 18,000 km3 annually.
• At present, only about a tenth of the domestic wastewater in developing countries is collected and only about a tenth of existing wastewater treatment plants operates reliably and efficiently.
• Some of the damage associated with inadequate handling of wastewater are:
- increased direct and indirect costs caused by increased illness and mortality
- higher costs for producing drinking and industrial water, resulting in higher tariffs
- loss of income from fisheries and aquaculture
- poor water quality, which deters tourists, immediately lowering income from tourism
- loss of valuable biodiversity
- loss in real estate values, when the quality of the surroundings deteriorates: especially important for slum dwellers where housing is the primary asset.
• Untreated sewage affects over 70% of coral reefs, precious habitats are disappearing and biodiversity is decreasing, fishing and agricultural potential are being lost, while poor water quality is reducing income from tourism and the value of real estate.
• The global burden of human disease caused by sewage pollution of coastal waters has been estimated at 4 million lost person-years annually.
• In March 2003, the World Panel on Financing Water Infrastructure estimated that US $56 billion was needed annually for wastewater treatment in order to achieve the target on sanitation.
• In the State of Mexico (Mexico), wastewater is generated approximately at the rate of 30 m3 per second (m3/s), about 19% of which is directly discharged without any kind of treatment.