Alternative Water Supply Research Articles

Multifunctional urban flood resilience enhancement strategies

Enhancing resilience in urban drainage systems (UDSs) can be achieved by implementing a range of strategies that minimise the magnitude and duration of flooding during or after the occurrence of unexpected system failures. Dual-purpose rainwater harvesting (RWH) systems provide a promising multifunctional resilience-enhancing strategy due to their associated multiple benefits such as water conservation and distributed control of storm water. However, their effectiveness in respect to minimisation of resulting flooding impacts and provision of alternative water supplies during unexpected system failures has not been explicitly investigated at a city district or catchment scale. This paper applies the global resilience analysis approach to investigate the effect of implementing a set of multifunctional RWH strategies on improvement of UDS resilience to random cumulative link (sewer) failure, using a case study of the Nakivubo system in Kampala, Uganda. The resulting water supply resilience enhancement benefits are also investigated. The study results reveal that catchment-scale implementation of suitably designed RWH systems provides an effective strategy that improves the system's global resilience to flooding by up to 25%, while simultaneously providing up to 30% of the household water supply requirements in the case study area.

Adaptation responses to increasing drought frequency

Using state contingent analysis, we discuss how and why irrigators adapt to alternative water supply signals. Focusing on the timing of water allocations, we explore inherent differences in the demand for water by two key irrigation sectors: annual and perennial producers. The analysis explores the reliability of alternative water property right bundles and how reduced allocations across time influence alternative responses by producers. Our findings are then extended to explore how management strategies could adapt to two possible future drier state types: (i) where an average reduction in water supply is experienced; and (ii) where drought becomes more frequent. The combination of these findings is subsequently used to discuss the role water reform policy plays in dealing with current and future climate scenarios.

<b>Estimation of water consumption in multifamily residential buildings

This article shows an estimation of water expenditure in multifamily residential buildings in the city of Joinville, located in south Brazil. The proposed method includes an investigation of the water expenditure and an evaluation of the particularities of each building. The investigation was accomplished in thirty buildings and the collected data allowed a classification of the buildings and a measurement of the water consumption rate. The water consumption in buildings with individualized and collective water measurement systems was analyzed. Furthermore, a comparative study was done between the water consumption in buildings that have at least one pool and buildings without any pools. Some buildings in the sample have an alternative water supply system; however there is no measurement of the water consumption in none of the cases analyzed in this study. The per capita consumption was 224 liters per person per day. The buildings with individualized water measurement had smaller consumption per capita than the buildings with collective measurement, showing a reduction of about 34%. The buildings with pools had consumption per capita nearly 48% more than the per capita consumption in buildings without pools.

A Fuzzy TOPSIS model Framework for Ranking Sustainable Water Supply Alternatives

Recently water supply alternative sources, recognized as sustainable and ecofriendly have become popular. This is consequent on the scarcity and increasing demand for water, especially by developing nations characterized by industrialization and increasing population growth. However, the intricacies and overwhelming nature of factors to be considered in reaching a decision on a best alternative has further prompted the emergence of several decision support tools, some of which arouse discrepancies with setbacks. We employ here, the uniqueness of fuzzy TOPSIS (technique for order preference by similarity to ideal solution), a multi-criteria decision approach (MCDA), to aid in deciding the most preferred alternative water supply among, desalination, water borehole, rain water harvesting, reclaimed water, black water, grey water and water importation. This method is reckoned for its ease in handling both quantitative and qualitative data. Moreover it also overcomes the uncertainties in expert opinions usually encountered in the decision process due to the numerous variables, criteria and attributes that interplay in achieving sustainability. Results from analysis on data aggregation, normalization and performance ratings, coupled with the weighted distance from the positive and negative ideal solutions indicated that borehole ranked topmost followed by rain water harvesting (RWH). These revelations are apt to all stakeholders in the water delivery sector and in deliberations on the paradigm shift to water conservation and management measure.

The Evolution of Water Supplies

Urban growth patterns in North America demonstrate how our water industry's thinking and practice concerning water supplies has evolved over time in response to changes in demand and technology. Leaving aside any political, social, or similar drivers, towns and cities generally establish themselves around freshwater sources like creeks, lakes, and aquifers. Yet as it grows, a community's water needs may come to exceed the limits of its original resources so that alternatives to augment local freshwater supplies are needed. As the feasibility of using alternative water supplies has improved, urban development has become less constrained by the proximity to and amount of local fresh water.

Wastewater Confronting Realities for Sustainable Livelihood in Developing Countries: Case Study Mekelle University, Ethiopia

Water is becoming a scarce resource in terms of quantity and quality. Water supply enhancement measures are being taken with less attention given to wastewater management, leading to increased discharge of untreated wastewaters. Wastewater is emerging as an affordable and reliable alternative water supply for urban agriculture, supporting thousands of farmers. Extensive use of untreated wastewater for irrigation will without a doubt lead to accumulation of heavy metals in soils and crops, resulting in overwhelming risks to both public health and the environment. This paper deals with determination of the strength and compositions of the wastewater from a public university in the tropical semiarid region for rainy and dry seasons, based on a number of key parameters including heavy metals. Furthermore, it identified the real advantages of treated water use and issues pertaining to untreated wastewaters use for irrigation purposes. An independent t test showed significant differences in concentrations of all the tested metals, excluding lead, copper, and cadmium during dry and wet seasons. Similarly, differences were significant for electrical conductivity, biological oxygen demand, total nitrogen and total phosphorus. Salinity and concentrations of organics, nutrients, copper, cadmium, iron, manganese and to some extent copper exceeded the allowable thresholds for irrigation water. Lead, zinc, nickel and chromium, on the other hand, were lower than their respective limits. Wastewater used for irrigation purposes is unsafe, and urgent policy interventions on the use of untreated wastewater are required.

Valuing Water Supply Reliability with Sensitivity Analysis

The purpose of this paper is to calculate the expected reliability benefits of alternative water supplies that are less vulnerable to disruption than the current composition of supplies, especially those regions which rely on imported surface water. Expected reliability benefits are measured using estimates of welfare losses under various levels of supply disruption, the probability of each level disruption, and on consumption forecasts over the life of proposed alternative supplies. To consider uncertainty in reliability benefits, we run sensitivity analyses to value reliability under different discount rates, the elasticities of demand, water supply disruption levels, and corresponding probability distributions of disruption.

Water trading opportunities and irrigation technology choice: An example from south India

Abstract Farmers as well as rural and urban consumers in India are facing water shortages. There is a need to increase efficiency in the supply and use of water. In this context, we consider the potential of a market in water, for improving water management in a small river basin wherein sixteen villages are the primary beneficiaries of a reservoir on the Varaha River. Using secondary data and observations from a household survey, we estimate the financial implications to farmers of shifting from traditional methods of cultivation, in four different scenarios (shifting to a better technology for cultivation, shifting to a dry land crop, shifting to short term cash crops, or leaving the land fallow). Our model suggests investing in better technology and less water intensive crops would not only benefit the farmers, adding to their income by selling the “saved” water, but also provide a cost efficient alternative water supply option to the government. Given that informal water markets already exist in the study area, formal transactions in water within the ambit of markets will not require a completely new institution and would be a ‘win-win’ situation for both the Government and the participating farmers.

Alleviating health risks associated with rainwater harvesting

Perceived and real public health risks associated with the quality of water from alternative water sources and supply systems, such as rainwater harvesting (RWH) and grey water reuse, continue to restrict their uptake in many countries. One option to alleviate these health risks is to treat alternative water to potable standard at the point of use (POU) as opposed to the point of supply, as undertaken in centralised systems. This paper presents the results of three international empirical field trials of a novel POU RWH treatment device. The results indicate that where the harvested rainwater did not contain elevated levels of pesticides or physico-chemical determinands, the POU device was able to reduce levels in outlet water to meet UK, EU and World Health Organization potable standards. Regarding microbiological determinands, such as total viable counts and coliforms, and microbial pathogens, such as Pseudomonas aeruginosa and Legionella spp., the device achieved reduction to potable standard and full pathogen removal, respectively. Thus, while it is possible to treat harvested rainwater to potable standard with a POU device, whether it is desirable to do so to alleviate risks for all end uses remains a question for further debate.

Avaliação físico-química e microbiológica de águas procedentes de soluções alternativas de abastecimento na Região Metropolitana da Baixada Santista, Estado de São Paulo, Brasil

Water is essential to life but its contamination may endanger public health. This study evaluated the physical-chemical and microbiological quality of alternative water supply solutions located in the Baixada Santista / SP. 67 samples (41 water spouts, 13 springs and 13 wells) were initially collected, and then 22 new collections were made. Total coliforms and Escherichia coli , according to the methodology of APHA (2012) and the contents of chloride, free residual chlorine (in treated waters), apparent color, hardness, iron, fluoride, nitrate, nitrite, odor, pH, total dissolved solids, and sulfate turbidity, were counted according to the techniques described by ANVISA (2005). Of the total of the samples, 56 (83,6%) were not in compliance with Decree 2914/2011 of the Ministry of Health, which refers to the potability of water for human consumption. The tests with the highest percentage of unsatisfactory results were E. coli , 39 (58,2%); apparent color 16 (23,9%) and nitrate, 15 (22,4%). A frequent monitoring of the quality of these waters is suggested – carrying out measures for their treatment, such as chlorination-, as well as a clarification to consumers about the quality of these waters by the competent bodies and the media for the benefit of the population’s health.

Multiobjective Optimization of Distributed Stormwater Harvesting Systems

AbstractStormwater harvesting (SWH) is an important water-sensitive urban design (WSUD) approach that provides an alternate water supply source and improves runoff quality through integrated system...

Assessment of Impact and Recovery Needs in Communities Affected by the Elk River Chemical Spill, West Virginia, April 2014.

In January 2014, 4-methylcyclohexanemethanol spilled into the Elk River near Charleston, West Virginia, contaminating the water supply for about 120 000 households. The West Virginia American Water Company (WVAWC) issued a "do not use" water order for 9 counties. After the order was lifted (10 days after the spill), the communities' use of public water systems, information sources, alternative sources of water, and perceived impact of the spill on households were unclear to public health officials. To assist in recovery efforts, the West Virginia Bureau for Public Health and the Centers for Disease Control and Prevention conducted a Community Assessment for Public Health Emergency Response (CASPER). We used the CASPER 2-stage cluster sampling design to select a representative sample of households to interview, and we conducted interviews in 171 households in April 2014. We used a weighted cluster analysis to generate population estimates in the sampling frame. Before the spill, 74.4% of households did not have a 3-day alternative water supply for each household member and pet. Although 83.6% of households obtained an alternative water source within 1 day of the "do not use" order, 37.4% of households reportedly used WVAWC water for any purpose. Nearly 3 months after the spill, 36.1% of households believed that their WVAWC water was safe, and 33.5% reported using their household water for drinking. CASPER results identified the need to focus on basic public health messaging and household preparedness efforts. Recommendations included (1) encouraging households to maintain a 3-day emergency water supply, (2) identifying additional alternative sources of water for future emergencies, and (3) increasing community education to address ongoing concerns about water.

Water Risk Drives Investment in Water Reuse, Alternative Business Models

As much of the US continues to face water scarcity and drought conditions, longstanding solutions to water supplies, including wastewater reuse, will play an increasing role in key water‐stressed markets. High population growth and high water usage are driving investment in alternative water supplies. Companies competing in the water space must rethink their business models to adjust to this ongoing reality.

An index for drought induced financial risk in the mining industry

AbstractWater scarcity has emerged as a potential risk for mining operations. High capital spending for desalination and water conflicts leading to asset stranding have recently occurred. Investors in mining companies are interested in the exposure to such risks across portfolios of mining assets (whether the practical at‐site consequences are foregone production, higher OPEX and CAPEX and ensuing lost revenues, or asset‐stranding). In this paper, an index of the potential financial exposure of a portfolio is developed and its application is illustrated. Since the likely loss at each mine is hard to estimate a priori, one needs a proxy for potential loss. The index considers drought duration, severity and frequency (defined by a return‐level in years) at each mining asset, and provides a measure of financial exposure through weighing of production or Net Asset Value. Changes in human needs are not considered, but are relevant, and could be incorporated if global data on mine and other water use were available at the appropriate resolution. Potential for contemporaneous drought incidence across sites in a portfolio is considered specifically. Through an appropriate choice of drought thresholds, an analyst can customize a scenario to assess potential losses in production value or profits, or whether conflicts could emerge that would lead to stranded assets or capital expenditure to secure alternate water supplies. Global climate data sets that allow a customized development of such an index are identified, and selected mining company portfolios are scored as to the risk associated with one publicly available drought index.

Biotechnological approach of greywater treatment and reuse for landscape irrigation in small communities.

A level of water quality intended for human consumption does not seem necessary for domestic uses such as irrigation of green spaces. Alternative water supplies like the use of greywater (GW) can thus be considered. However, GW contains pathogenic microorganisms and organic compounds which can cause environmental and health risks. As the risks related to recycling are unknown, GW treatment is necessary before reusing. To describe the risks related to GW reuses, the scientific approach performed in this study was to characterize domestic GW in order to select an appropriate treatment. The biotechnology chosen is a Horizontal sub-surface flow constructed wetland reactor. In order to minimize health risks, an optimization step based on UV disinfection was performed. The treatment performances were then determined. The treated GW produced in this study reached the threshold values expected by the Moroccan regulation for irrigation of green spaces with treated wastewater. Indeed, the COD and the TSS obtained in treated GW without disinfection are respectively 16.6 mg O2 L−1 and 0.40 mg L−1. The horizontal sub-surface flow constructed wetland (HSSF CW) reactor has been used to treat 1.2 m3/d of GW for 100 days. Three lawn plots have been irrigated respectively with raw GW, treated GW and tap water as a reference. Contrary to the lawn plot irrigated with raw GW, the risk analysis performed in this study has shown no significant difference between the law plots irrigated with treated GW combined with UV disinfection and the one irrigated with tap water. Overall, UV disinfection treated GW produced from the HSSF CW reactor developed in this experiment is thought to be an effective and feasible alternative for agricultural reuse.

Potentials of Rainwater Harvesting as an Alternative Water Supply System in Dhaka City

Potentials of Rainwater Harvesting as an Alternative Water Supply System in Dhaka City

Sanitation safety planning as a tool for achieving safely managed sanitation systems and safe use of wastewater.

Increasing water stress and growing urbanization force a greater number of people to use wastewater as an alternative water supply, especially for irrigation. Although wastewater irrigation in agriculture has a long history and substantial benefits, without adequate treatment and protective measures on farms and in markets, use of wastewater poses risks to human health and the environment. Against this background, the World Health Organization (WHO) published Guidelines for the safe use of wastewater, excreta and greywater in agriculture and aquaculture, in 2006. The Sanitation safety planning: manual for safe use and disposal of wastewater, greywater and excreta - a step-by-step risk-based management tool for sanitation systems - was published by WHO in 2016 to put these guidelines into practice. Sanitation safety planning (SSP) can be applied to all sanitation systems, to ensure the systems are managed to meet health objectives. This paper summarizes the pilot-testing of the SSP manual in India, Peru, Portugal, Philippines, Uganda and Viet Nam. Also reviewed are some of the key components of the manual and training, and an overview of SSP training and dissemination efforts and opportunities for implementation in the WHO South-East Asia Region. Lessons learnt during the piloting phase show how reducing health risks can be surprisingly easy, even in a low-income setting, especially when combining many smaller measures. The SSP approach can make an important contribution towards Sustainable Development Goal target 6.3, by reducing pollution, eliminating dumping and minimizing the release of hazardous chemicals and materials, thereby halving the proportion of untreated wastewater and substantially increasing recycling and safe reuse globally.

Rainwater Harvesting (RWH) and Groundwater Potential as Alternatives Water Resources in Malaysia: A Review

Socio-economic growth at present exerting pressure on the capacity of water supply. Water has been harvested worldwide since antiquity, thus, it is essential to manage the potential available of natural water supplies in the catchment to save water for dry periods when the supply-demand gap is comparatively high. The overall aim of this paper is to present a general overview of rainwater harvesting system and groundwater, and their potential applications for daily use. Many countries have implement the rainwater harvesting system as a sustainable approach for supplementing their public water supply. In Malaysia, the guidelines for rainwater harvesting implementations was first created in 1999 and developed by time to time to attract users. By using the system, the main findings reveals that it has overcome several of water problem issues. Groundwater is another alternative water supply that can be counted. Research has found that the availability of groundwater in few states in Malaysiawas in freshwater category based on its hardness level results. Thus, conclusions and recommendations are drawn where the gaps exist and more research needs to be focussed.

Application of Ceramic Filter for Improvement of Pond Sand Filter’s Water Quality

Paying attention to the use of surface water a household type filter unit adding with existing Pond Sand Filter (PSF) is introduced as an alternative water supply option where groundwater is contaminated with arsenic/iron or excessive saline and freshwater aquifers are not available. The performances of existing PSFs are not satisfactory due to poor operation and maintenance, shorter filter run and poor treated water quality. In this study a simple and low cost ceramic filter unit consists of clay pot (10L-capacity), ceramic filter core, storage tank and wooden stand, were applied. The combined action of PSF with ceramic filter unit, the average total coliform and fecal coliform removal efficiencies were found to be 99.73% and 99.97% respectively. Moreover, the reduction efficiencies of turbidity, and color were also achieved to be 96.89% and 99.90% respectively. The average discharge rate of the filter was observed to be 3.0 lit/hr. In combination with PSF, this kind of ceramic filter would be a reliable and sustainable treatment option particularly appropriate for problematic area in Bangladesh.

How Governance Regimes Shape the Implementation of Water Reuse Schemes

The governance dimensions of water reuse scheme development and operation, such as policies and regulatory frameworks, and public involvement and stakeholder collaboration, can serve to both facilitate and constrain wider adoption of water reuse practices. This paper explores the significance and underlying structure of the key governance challenges facing the water reuse sector in Europe. It presents empirical evidence from interviews and focus group sessions conducted at four water reuse schemes: an indirect potable reuse scheme at Torreele (Belgium), the urban reuse of treated municipal wastewater at the London Olympic Park (United Kingdom) and at Sabadell (Spain), and the reuse of agro-industrial effluent for irrigation at Capitanata (Italy). The findings underscore the importance of clarity in policy arrangements around water reuse, as well as of the financial competitiveness of reuse projects compared to alternative water supply options. Operators of water reuse schemes expressed a preference for water quality standards, which focus on appropriateness for use rather than over-emphasise the waters’ origin so that unnecessary treatment and costs can be avoided. Positive public support was widely acknowledged as an important factor in the success or failure of water reuse schemes. We conclude that constructive institutional relationships underpin many of the challenges faced by reuse scheme operators and that greater emphasis should be given to building confidence and gaining trust in water service providers through early identification of how governance regimes shape the viability of new schemes.