Showing papers on "Water supply published in 2009"

Assessing the environmental impacts of freshwater consumption in LCA

Abstract: A method for assessing the environmental impacts of freshwater consumption was developed. This method considers damages to three areas of protection: human health, ecosystem quality, and resources. The method can be used within most existing life-cycle impact assessment (LCIA) methods. The relative importance of water consumption was analyzed by integrating the method into the Eco-indicator-99 LCIA method. The relative impact of water consumption in LCIA was analyzed with a case study on worldwide cotton production. The importance of regionalized characterization factors for water use was also examined in the case study. In arid regions, water consumption may dominate the aggregated life-cycle impacts of cotton-textile production. Therefore, the consideration of water consumption is crucial in life-cycle assessment (LCA) studies that include water-intensive products, such as agricultural goods. A regionalized assessment is necessary, since the impacts of water use vary greatly as a function of location. T...

A review of the potential impacts of climate change on surface water quality

Abstract: It is now accepted that some human-induced climate change is unavoidable. Potential impacts on water supply have received much attention, but relatively little is known about the concomitant changes in water quality. Projected changes in air temperature and rainfall could affect river flows and, hence, the mobility and dilution of contaminants. Increased water temperatures will affect chemical reaction kinetics and, combined with deteriorations in quality, freshwater ecological status. With increased flows there will be changes in stream power and, hence, sediment loads with the potential to alter the morphology of rivers and the transfer of sediments to lakes, thereby impacting freshwater habitats in both lake and stream systems. This paper reviews such impacts through the lens of UK surface water quality. Widely accepted climate change scenarios suggest more frequent droughts in summer, as well as flash-flooding, leading to uncontrolled discharges from urban areas to receiving water courses and estuaries. Invasion by alien species is highly likely, as is migration of species within the UK adapting to changing temperatures and flow regimes. Lower flows, reduced velocities and, hence, higher water residence times in rivers and lakes will enhance the potential for toxic algal blooms and reduce dissolved oxygen levels. Upland streams could experience increased dissolved organic carbon and colour levels, requiring action at water treatment plants to prevent toxic by-products entering public water supplies. Storms that terminate drought periods will flush nutrients from urban and rural areas or generate acid pulses in acidified upland catchments. Policy responses to climate change, such as the growth of bio-fuels or emission controls, will further impact freshwater quality.

Water for Agriculture: Maintaining Food Security under Growing Scarcity

Abstract: Irrigated agriculture is the main source of water withdrawals, accounting for around 70% of all the world’s freshwater withdrawals. The development of irrigated agriculture has boosted agricultural yields and contributed to price stability, making it possible to feed the world’s growing population. Rapidly increasing nonagricultural demands for water, changing food preferences, global climate change, and new demands for biofuel production place increasing pressure on scarce water resources. Challenges of growing water scarcity for agriculture are heightened by the increasing costs of developing new water, soil degradation, groundwater depletion, increasing water pollution, the degradation of water-related ecosystems, and wasteful use of already developed water supplies. This article discusses the role of water for agriculture and food security, the challenges facing irrigated agriculture, and the range of policies, institutions, and investments needed to secure adequate access to water for food today and in the future.

Water safety plan manual: Step-by-step risk management for drinking-water suppliers.

Abstract: The most effective means of consistently ensuring the safety of a drinking-water supply is through the use of a comprehensive risk assessment and risk management approach that encompasses all steps in water supply from catchment to consumer. In these Guidelines such approaches are called water safety plans (WSPs). The aim of this Manual is to provide that practical guidance to facilitate WSP development focusing particularly on organized water supplies managed by a water utility or similar entity. (Excerpts)

Energy and air emission effects of water supply.

Abstract: Life-cycle air emission effects of supplying water are explored using a hybrid life-cycle assessment. For the typically sized U.S. utility analyzed, recycled water is preferable to desalination and comparable to importation. Seawater desalination has an energy and air emission footprint that is 1.5−2.4 times larger than that of imported water. However, some desalination modes fare better; brackish groundwater is 53−66% as environmentally intensive as seawater desalination. The annual water needs (326 m3) of a typical Californian that is met with imported water requires 5.8 GJ of energy and creates 360 kg of CO2 equivalent emissions. With seawater desalination, energy use would increase to 14 GJ and 800 kg of CO2 equivalent emissions. Meeting the water demand of California with desalination would consume 52% of the state’s electricity. Supply options were reassessed using alternative electricity mixes, including the average mix of the United States and several renewable sources. Desalination using solar th...

Public Private Partnerships for Urban Water Utilities: A Review of Experiences in Developing Countries

Abstract: This study provides objective information and analysis on the performance of public-private partnerships (PPP) projects in urban water supply and sanitation in developing countries. It reviews the spread of urban water PPP projects during the past 15 years, and assesses whether and how they have helped to improve services and expand access for the populations concerned. The study uses a structured framework to assess the performance of more than 65 large water PPP projects that have been in place for at least five years (three years in the case of management contracts) and that provide services to a combined population of almost 100 million. By population size, this sample represents close to 80 percent of the water PPP projects that were awarded before 2003 and have been active for at least three years. The analysis focuses on the actual impact of these projects for the concerned populations, that is, the net improvements achieved under these partnerships. Chapter two summarizes the historical development of water PPPs in developing countries, reviewing the current state of the market, the rate of contract cancellations, and the evolution of the industry. Chapter three reviews the performance of PPP projects in terms of access, service quality, operational efficiency, and tariffs. Chapter four draws conclusions and lessons on how to make public-private partnership a more viable and sustainable option for improving water supply and sanitation (WSS) services in the developing world.

Water quality improvement through macrophytes--a review.

Abstract: Increasing urbanization, industrialization and over population is leading to the degradation of the environment. The main hazardous contents of the water pollution are heavy metals etc. Water bodies are the main targets for disposing the pollutants directly or indirectly. They are again at the receiving end as the storm water, residential and commercial waste is disposed into it. The prevailing purification technologies used to remove the contaminants are too costly and sometimes non-eco friendly also. Therefore, the research is oriented towards low cost and eco friendly technology for water purification, which will be beneficial for community. The present paper is a comprehensive review of approximately 38 literature sources. The paper discusses the potential of different aquatic plants (macrophytes) in purifying water and wastewater. Experimental work was developed to test the hypothesis that nutrient enrichment enhances metal tolerance of relative macrophyte.

Evolving Urban Water and Residuals Management Paradigms: Water Reclamation and Reuse, Decentralization, and Resource Recovery

Abstract: Population growth and improving standards of living, coupled with dramatically increased urbanization, are placing increased pressures on available water resources, necessitating new approaches to urban water management The tradition linear "take, make, waste" approach to managing water increasingly is proving to be unsustainable, as it is leading to water stress (insufficient water supplies), unsustainable resource (energy and chemicals) consumption, the dispersion of nutrients into the aquatic environment (especially phosphorus), and financially unstable utilities Different approaches are needed to achieve economic, environmental, and social sustainability Fortunately, a toolkit consisting of stormwater management/rainwater harvesting, water conservation, water reclamation and reuse, energy management, nutrient recovery, and source separation is available to allow more closed-loop urban water and resource management systems to be developed and implemented Water conservation and water reclamation and reuse (multiple uses) are becoming commonplace in numerous water-short locations Decentralization, enabled by new, high-performance treatment technologies and distributed stormwater management/rainwater harvesting, is furthering this transition Likewise, traditional approaches to residuals management are evolving, as higher levels of energy recovery are desired, and nutrient recovery and reuse is to be enhanced A variety of factors affect selection of the optimum approach for a particular urban area, including local hydrology, available water supplies, water demands, local energy and nutrient-management situations, existing infrastructure, and utility governance structure A proper approach to economic analysis is critical to determine the most sustainable solutions Stove piping (ie, separate management of drinking, storm, and waste water) within the urban water and resource management profession must be eliminated Adoption of these new approaches to urban water and resource management can lead to more sustainable solutions, defined as financially stable, using locally sustainable water supplies, energy-neutral, providing responsible nutrient management, and with access to clean water and appropriate sanitation for all

Development of a water quality index based on a European classification scheme

Abstract: This study comprised the development of a new index called the 'universal water quality index (UWQI)'. This index has advantages over pre-existing indices by reflecting the appropriateness of water for specific use, e.g. drinking water supply rather than general supply, and has been developed by studying the supranational standard, i.e. the European Community Standard. Three classification schemes for water quality are proposed for surface water quality assessment. Water quality determinants of the new index are cadmium, cyanide, mercury, selenium, arsenic, fluoride, nitrate-nitrogen, dissolved oxygen, biochemical oxygen demand, total phosphorus, pH and total coliform. The mathematical equations to transform the actual concentration values into quality indices have been formulated. The weighted sum method was proposed to obtain overall index scores based on individual index (sub-index) values. The application of the new index was demonstrated at a sampling station on Tahtali Reservoir in Turkey based on observed water quality data. Results revealed that the overall quality of the surface water falls under the 'excellent' class. On the other hand water quality was strongly affected by agricultural and domestic uses. This technique is believed to assist decision makers in reporting the state of the water quality, as well as investigating spatial and temporal changes. It is also useful to determine the level of acceptability for the individual parameter by referring to the concentration ranges defined in the proposed classification scheme.

Meeting China’s Water Shortage Crisis: Current Practices and Challenges

Abstract: China needs to and is undertaking several initiatives to conserve its water supply for human health and national productivity.

System Dynamics Analysis for Managing Iran’s Zayandeh-Rud River Basin

Abstract: Within river basins different social, economic, political and physical subsystems interact. When making decisions, policy makers should be aware of such interactions as any new policy will affect more than one subsystem. To determine the adequacy of a specific management policy, an integrated study is needed of a complicated water management system in the basin considering major physical, social, economic and political aspects. The Zayandeh-Rud river basin, in central Iran with a semi-arid climate and large agricultural, industrial and domestic water uses, is an example of a complicated watershed system where the lack of complete knowledge about all the interacting subsystems has led to failure of the policy makers in addressing the water shortage in the basin. Although water shortages occur fairly soon after completion of each new water source, transbasin water diversion is still the major policy of water planners to address ongoing shortages. System dynamics provides a unique framework for integrating the disparate physical, socio-economic and political systems important to watershed management. This approach is used to comprehend the interactions of different drivers of the problem and to convey the experiences, lessons learned, and perceptions gained during the model development process. A simulation model, built based on causal loop diagrams of the problem, shows that transbasin diversion is not the best and only solution to the problem. The results of the model for different scenarios suggest that various options of demand management and population control can be more effective in addressing the water crisis of the basin when combined with transbasin water diversions, increasing water storage capacity and controlling of groundwater withdrawal.

Indirect potable reuse: a sustainable water supply alternative.

Abstract: The growing scarcity of potable water supplies is among the most important issues facing many cities, in particular those using single sources of water that are climate dependent. Consequently, urban centers are looking to alternative sources of water supply that can supplement variable rainfall and meet the demands of population growth. A diversified portfolio of water sources is required to ensure public health, as well as social, economical and environmental sustainability. One of the options considered is the augmentation of drinking water supplies with advanced treated recycled water. This paper aims to provide a state of the art review of water recycling for drinking purposes with emphasis on membrane treatment processes. An overview of significant indirect potable reuse projects is presented followed by a description of the epidemiological and toxicological studies evaluating any potential human health impacts. Finally, a summary of key operational measures to protect human health and the areas that require further research are discussed.

Water and sanitation

Abstract: Introduction The 1980s were designated the International Water and Sanitation Decade, and the international community committed itself to ensuring that everyone in the world would have access to at least basic water and sanitation services by 1990. This target was not met. While hundreds of millions did receive access to new services, at the end of the decade well over 1.1 billion people still lacked improved water supplies, and more than 2.7 billion lacked sanitation services. By the year 2000, although another billion people had obtained access to improved water and sanitation services, population growth had left the number of those still unserved at roughly the same absolute level. In 2002, at the Johannesburg World Summit on Sustainable Development, the global community made a new commitment to a set of Millennium Development Goals (MDGs), including environmental sustainability. One of the targets under the environmental sustainability MDG is to cut by half the proportion of people in the world living without access to water and sanitation by 2015. While we certainly hope that the global target for water and sanitation will be met this time, there are grounds for concern. Some important physical and economic features of water supply and sanitation make it inherently difficult to achieve broad-scale goals such as those of the International Water and Sanitation Decade and the MDG water and sanitation target – more difficult than for other MDG targets such as providing access to affordable essential drugs or communication and information technology.