Global Environment Outlook 3 (GEO 3)

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STATE OF THE ENVIRONMENT AND POLICY RETROSPECTIVE: 1972–2002

Groundwater quality problems

Problem

Causes

Concerns

Anthropogenic pollution

Inadequate protection of vulnerable aquifers Pathogens, nitrates, ammonium salts, chlorine, against human-made discharges sulphates, boron, heavy metals, DOC, aromatic and leachates from: and halogenated hydrocarbons urban and industrial activities; intensification of agricultural cultivation nitrates, chlorine, pesticides Related to pH-Eh evolution of groundwater Mainly iron, fluorine and sometimes arsenic, and dissolution of minerals (aggravated by iodine, manganese, aluminium, magnesium, anthropogenic pollution and/or uncontrolled sulphates, selenium and nitrates (from paleo- exploitation) recharge)

Naturally occurring contamination

Well-head contamination

Inadequate well design and construction allowing direct intrusion of polluted surface water or shallow groundwater

Mainly pathogens

Source: Foster, Lawrence and Morris 1998

West Asia, the former Soviet Union, the western United States and the Arabian Peninsula are experiencing declining water tables, limiting the amount that can be used and raising the costs of pumping to farmers (Postel 1997, UNEP 1999). Overpumping of groundwater can lead to salt-water intrusion in coastal areas. In Madras, India, for example, saltwater intrusion has moved 10 km inland, contaminating wells (UNEP 1996). Concern over growing problems related to groundwater resources has galvanized the international community, governments and other stakeholders to start addressing them. For example,

the Second World Water Forum in March 2000 organized a special workshop on groundwater. Some of the recommendations arising from the workshop included the need to raise public awareness and ‘improve information availability, quality and accessibility to stakeholders, technical specialists and policy-makers’ (World Water Forum 2000). Transboundary water management Water is widely shared among nations, regions, ethnic groups and communities. A total of 261 rivers (see graphic left), covering 45.3 per cent of the total land area (excluding Antarctica), are shared by two or more countries (Wolf and others 1999), making transboundary water resources management one of the most important water issues today. Disputes over shared water resources have a long history. Water has been used as a tool and weapon of conflict, access to water has been a source of dispute and contention, and major water development projects (for example dam construction) have led to violence and civil strife (Gleick 1998). But shared waters can also be a source of cooperation. This is particularly evident today with the increase in the number of initiatives related to river basin management regimes and institutions committed to bilateral and/or multilateral management of transboundary water resources. This can be traced back to the 1966 Helsinki Rules which laid the foundation for international principles for shared watercourses and

Numbers of international river basins

Europe

71

Asia

53

South America

38

North and Central America

39

Africa

60

A total of 261 river basins are shared by two or more countries

Notes: regions do not correspond exactly to GEO regions; the Jurado, shared by Colombia and Panama, is included in South America Source: Wolf and others 1999