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About UNEP
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United Nations Environment Programme
Division of Technology, Industry and Economics
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Freshwater Issues

Please note that resources contained in this page are derived from previous/closed Work Programmes (~ 2004). The information presented here is for archival purposes only. For current on-going activities, please see http://www.unep.or.jp/
Background
Sewage
Reference
Background

The management of freshwater basins is also of prime concern to IETC. Lakes are one of the planet's most important freshwater resources providing water for domestic, agricultural and industrial uses for much of the world's population. We are all familiar with the image of Earth as the "blue planet" when seen from space. It gives the impression that water is plentiful and indeed it is. However, pictures can be deceiving. Freshwater only accounts for 2.15 per cent of all the Earth's water. But even that percentage is deceiving because 99.5 per cent of all surface freshwater is locked away in continental ice. The present state of fresh water is mainly include the following problems: freshwater augmentation, waste water and storm water, eutrophication of lakes and reservoirs, sewage and public health problems. These problems will be introduced and discussed by topic. Freshwater, therefore, is a scarce resource, often a limiting factor for development, and one which we should take great care to protect.

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Freshwater Augmentation

Freshwater resources are vital for meeting basic human needs and inadequate protection of the quality and the supply of freshwater can set important limits to sustainable development. Many health hazards in developing countries and transition-economy countries are related to poor water quality and limited water quantity. Many of these countries use more than their annual freshwater renewal rate by satisfying demands from non-renewable resources. This water shortage is expected to worsen as a result of several factors including population growth compounded by continued rural-urban migration, pollution of surface water sources, and an increase in the standard of living resulting in growing demand.

Traditionally, governments respond to extra demand by increasing the water supply for urban dwellers; a practice which is becoming more and more difficult as sources of good quality water become geographically more distant, making it more expensive to explore and develop. Abstraction of ground water will not make up the difference either as over-pumping has lead to salt-water intrusion and a lowering of water tables in many parts of the world. Planners must therefore make wider use of both conventional and non-conventional technologies for maximizing the use and augmenting freshwater resources.

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Pollution in Lakes and Reservoirs

Lakes and reservoirs have special characteristics due to their nature and dynamics that make them to be vulnerable to pollution. Over time the loading of contaminants has resulted in the degradation of the water quality and loss of biodiversity due to various causes including eutrophication. Eutrophication of lakes and reservoirs is becoming more serious due to the continuous loading of organic matter, phosphorous and nitrogen into these water bodies. The nutrients are originated mainly from agricultural run-off as well as from industrial and urban discharges. Fertilizers from agriculture as well as domestic and industrial sewage are constantly entering these water bodies directly as well as through rivers and streams; water treatment facilities are constructed to ameliorate the problem but the integrated management of the basin, use of alternative technologies as well as public participation is still lacking.

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Waste Water and Storm Water

It addresses two issues: managing waste water to avoid further degradation of the environment, particularly the freshwater resource; and increasing access/availability of freshwater by recovering / reuse / etc. Planning and implementing integrated waste water collection and treatment systems is one of the major environmental concerns confronting cities in developing countries and countries in transition. Many cities have been constructing sewers, but few are equipped with treatment facilities.

As we observe in many cities around the world, sewerage facilities are also utilized to transport stormwater runoff during the storm event. Cities with limited ground permeability due to the artificial surface coverage are vulnerable to flooding unless proper stormwater discharge measures were materialized. Stormwater discharge system has to be considered when planning urban sewage system. The magnitude of stormwater runoff pollution has proved to be substantial and thus proper measure should be taken into account as well.

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Sewage

In the developing world, it is estimated that more than 90 percent of sewage is discharged directly into rivers, lakes, and coastal waters without treatment of any kind. However, the amount of water used in those cities has been increasing as their economy evolves. Untreated waste water has damaged the environment of receiving water bodies. Thus, it is recognized that the need for integrated waste water management consisting of capture, transport, treatment, recovery and discharge is a high priority in many large cities in developing countries and countries in transition. Technologies to treat and manage waste water vary depending on the characteristics of sewage and the quality standard of effluent required. Handling of sewage sludge is another crucial issue, but it is seldom considered by urban planners. Operation and maintenance of the system is also an important aspect in tailoring the sewage programme.

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Public Health Problem

Perhaps more than any other sector, Water Supply and Sanitation hits on all the main themes of the development agenda: poverty alleviation, environmental sustainability, private sector-led growth, participatory development and good governance. The challenge is enormous: over one billion people still lack access to safe water, and nearly two billion lack safe sanitation. Slow progress is not acceptable, as more than three million people still die every year from avoidable water-related disease. In helping our members rise to meet this challenge, we seek to foster approaches that are people-centered, market-based and earth-friendly. Despite large investments in water and sanitation in the 1980s and 1990s, the number of people without access to water and sanitation services in urban and peri-urban areas continues to grow.

Given the crucial importance of water for health and the projected increase in domestic water demand, a special study addressed the "water satisfaction rate." This is the ratio of the per catchment water supply (the result of calculating the monthly surface runoff and ground-water recharge from monthly precipitation and potential evaporation data) to the total demand in the catchment area (domestic, industrial, and agricultural demand).

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Related Institutions Links

Our many projects on fresh water are being implemented by cooperating with International Lake Committee Foundation ( ILEC ). Collaborations with other relevant organizations are also sought. International Water Association ( IWA ) provided suggestions to develop the scope and framework of these projects. Japanese Sewage Works Association ( JSWA ), Infrastructure Development Institute of Japan ( IDI ) and relevant Ministries of Japan provided useful information on the current practices in developing countries. Finally, we have established collaborative partnership with UNDP - World Bank's "Water and Sanitation Program ( WSP )" so that our "Source Book" and their "Resource Guide" will be complementary and comprehensive each other.

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Reference

This paper was written mainly base on the materials on the homepages of UNEP and IETC, The World Bank and The UNDP-World Bank Water and Sanitation Program (WSP), especially the following report:Vandeweerd, V.; Cheatle, M.; Henricksen, B.; Schomaker, M.; Seki, M.; Zahedi, K., Global Environment Outlook (GEO) ― UNEP Global State of Environment Report 1997

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