Water Supply Costs Research Articles

Simulation of Water Allocation Optimization Problem

Pollution prevention is primarily stimulated by economics, legislation, liability concerns, and the enhanced environmental benefit of managing waste at source. Chemical process industries consume a huge amount of water. Consequently, wastewater streams from such industries which contain various contaminants may create environmental problem. The increasing cost of fresh water supply and wastewater treatment has encouraged process industries to minimize fresh water consumption and waste water generation. This paper presents a formulation of water allocation problem (WAP) in order to minimize fresh water consumption in multi contaminant mass exchanger network. The approach is based on mass balance equation within the system being studied. The problem were then solved by using Matlab Optimization Toolbox.

FEATURES OF CALCULATION OF THE COST OF WATER FOR AGRICULTURAL ORGANIZATIONS

The article deals with the problems and features of calculating the cost of water for agricultural organizations, analyzed the relationship between the owners of water supply systems and specialized enterprises in the operation of water supply systems. This allowed: 1) to create organizational models for the operation of water supply systems of agricultural organizations; 2) to clarify the grouping of costs for the calculation of the cost of water of agricultural organizations; 3) to develop a methodology for calculating the cost of water for agricultural organizations in order to create a unified approach to the calculation of water supply costs and search for savings reserves.

Revisiting the water-use efficiency performance for microelectronics manufacturing facilities: Using Taiwan’s Science Parks as a case study

Semiconductors are enabling technologies that drive today’s information economy by producing a broad spectrum of microelectronic consumer products including computers, flat-panel displays, sensors, storage devices, and lighting devices. Manufacturing of these semiconductor devices and products is capital and resources intensive and typically operates with either a vertically integrated manufacturing mode or with a cluster of supply-chain partnering companies in the vicinity of each other. Our research group has previously reported the water recycling and reuse efficiencies of “fabs” in the Science Parks in Taiwan (Lin et al., Res. Cons. Recycl. 2015), which exemplify this unique cluster of tech-manufacturing fabs demanding intensive supply of water and energy. We extend our discussion by summarizing the status of water consumption of major semiconductor and optomicroelectronic plants, and the industry’s collective and individual water reuse goals. Though the geographical location of fabs plays an important part of the water reuse efficiency, the industry generally displays a strong urgency to use water responsibly to maintain corporates’ competitiveness and to effectively manage the risks associated with water shortage. Additionally, the examination of water and energy expenditures of semiconductor fabs indicated a close water-energy relationship in the compartment of ultrapure water production process. The energy needed to treat, recycle and reuse spent water is secondary as compared to the energy demand for manufacturing processes. Using the industrial cluster in Taiwan as an example to illustrate the potential of improve water reuse through collaborative schemes, we conducted a survey-based study to assess how the industry perceived the proposed “inter-plants” and “inter-park” schemes designed to create a reclaimed water trading mechanism in place of the existing “in-plant” practice of water reclamation. Respondents showed an overall positive perception to such schemes on the basis of reducing water and energy demands in a cost-effective manner. The cost of water supply was a dominant factor in the perceived extent of benefits.

The Effects of Agricultural Water Pricing Policies on the Sustainability of the Water Resources: A Case of Irrigation Network in Qazvin Plain

Qazvin plain in Iran is one of the most fertile regions for crop production, but it has been suffering from severe crises in water resources, inefficient water allocation, and improper cropping pattern due to low tariffs in recent years. One influential policy in the context of sustainable water re source management is suitable pricing. Given the legal potentials and technical conditions for the adoption of various pricing policies, the present paper addresses the effect of area, volumetric or two-part tariff pricing policies with the scenarios of pricing by water supply cost, economic value, or residual value of water on economic variables and water use rate. To this end, positive mathematical programming method was adopted and the data were collected through a questionnaire from the farmers served by the irrigation network of Qazvin plain. Also, experts’ opinions were collected and a library study was conducted. The results show that area pricing policy has no impact on water use management in crops irrigated with sprinkler or flood systems and increased water use by as high as 72% in alfalfa farms irrigated by flood system. Volumetric policy and two-part tariff policy reduces water use by as high as 45% in most cropping systems with various irrigation technologies and encourages farmers to use sprinkler or tape irrigation technologies. However, given the negative economic impacts of these pricing policies on local farming, it is imperative to offset their adverse impacts by alternative policies that can improve water resource sustainability and at the same time, do not cause fluctuations in economic interests of users.

A Continental‐Scale Hydroeconomic Model for Integrating Water‐Energy‐Land Nexus Solutions

AbstractThis study presents the development of a new bottom‐up large‐scale hydroeconomic model, Extended Continental‐scale Hydroeconomic Optimization (ECHO), that works at a subbasin scale over a continent. The strength of ECHO stems from the integration of a detailed representation of local hydrological and technological constraints with regional and global policies, while accounting for the feedbacks between water, energy, and agricultural sectors. In this study, ECHO has been applied over Africa as a case study with the aim of demonstrating the benefits of this integrated hydroeconomic modeling framework. Results of this framework are overall consistent with previous findings evaluating the cost of water supply and adaptation to global changes in Africa. Moreover, results provide critical assessments of future investment needs in both supply‐ and demand‐side water management options, economic implications of contrasting future socioeconomic and climate change scenarios, and the potential trade‐offs among economic and environmental objectives. Overall, this study demonstrates the capacity of ECHO to address challenging research questions examining the sustainability of water supply and the impacts of water management on energy and food sectors and vice versa. As such, we propose ECHO as useful tool for water‐related scenario analysis and management options evaluation.

U.S. Urban Water Prices: Cheaper When Drier

AbstractPublic water utilities are called upon to address multiple and often partially conflicting objectives, allocating potentially scarce water in an efficient and equitable manner while covering the costs of water supply. Economists typically advocate using prices to balance supply and demand of a scarce resource. But high prices necessary to balance supply and demand for scarce water may unduly burden poor households. We analyze the pricing policy of public water utilities in the major city of the 35 largest metropolitan areas in the United States. We would expect water prices to be higher in water‐stressed regions. However, we find the opposite pattern in the data: cities facing greater water scarcity tend to have lower water prices. Sacramento, Las Vegas, and Phoenix, have the lowest water prices. To address equity and ensure that all households have access to water, we would expect low prices on essential water use with higher prices for additional water beyond essential use. However, we find that the majority of cities have higher per unit water prices (average price) for low use than for high use. Such pricing may leave major urban areas in the United States ill‐prepared to meet future water shortages in an equitable manner.

A Review of the Suitability of Using Eco-Efficiency Principles in Managing Environmental Impacts of the Packaged Water Industry in Ghana

The production and use of sachet water in Ghana has been consistently increasing, filling the gap of inadequate access to safe drinking water. Despite the obvious significant socio‑economic impact of the packaged water industry in Ghana, the associated environmental impacts of the production and use cannot be overlooked. The aim of this paper is to analyze the prospects of eco‑efficiency approach as a more sustainable means of production in the industry, leading towards the sustainable development agenda of the country. The methodology employed in this paper is desktop research with qualitative data collection and analysis, utilizing existing literature or secondary data. It was concluded that there are many good reasons for adopting an eco‑efficiency in the packaged water industry, including reducing operating costs and improve profitability by reducing energy, water supply, and solid waste costs, reducing water wastage and contribute in developing solid waste minimization plans. The significance of this paper is to increase the awareness of the effect of improper disposal of sachet waste on the Ghanaian environment and also seeks to inform the management of the many companies in the packaged water industry, stakeholders and consumers to be environmentally responsible, as their actions can help protect and improve the natural environment while improving the overall economy.

Comparison of Nanofiltration and Direct Contact Membrane Distillation as an alternative for gold mining effluent reclamation

Effluent reuse is becoming an environmentally-economically viable option for industries that have been struggling with environmental/legislative pressure and high costs of water supply and effluents discharge. Mining effluents are promising for reuse, but for this, (hazardous) metals and ions such as sulfate must be removed efficiently. This study aimed to compare the technical-economic performance of Nanofiltration (NF) and Direct Contact Membrane Distillation (DCMD) on gold mining effluent treatment. The results showed that both technologies are promising for mining effluent reclamation as high pollutants removal rates were observed (rejection >73% and >96% for NF and DCMD, respectively). DCMD showed lower flux than NF and was limited to operate up to permeate recovery rate (RR) of 40% due to severe fouling (CaSO4 precipitation), but produced a higher quality permeate with no reuse restriction, low energy requirement and lower associated costs due to use of the effluent residual heat. Capex and Opex (for membrane lifespan of 1–5 years) were estimated at US$ 575,490.30 and 2.00–2.10 US$/m3 for NF and US$ 305,483.85 and 0.13 to 0.27 US$/m3 for DCMD systems. The permeate reuse would reduce water consumption in 490,560 m3 year−1, which represents almost 50% of the industrial water demand.

Integrated modelling for economic valuation of the role of forests and woodlands in drinking water provision to two African cities

Rapidly growing economies often have high population growth, resulting in agricultural expansion in rural areas and increased water demand in urban areas. Conversion of forests and woodlands to agriculture may threaten safe and reliable water supply in cities. This study assesses the regulating functions and economic values of forests and woodlands in meeting the water needs of two major cities in Tanzania and proposes an integrated modelling approach with a scenario-based analysis to estimate costs of water supply avoided by forest conservation. We use the process-based hydrological Soil and Water Assessment Tool (SWAT) to simulate the role of woody habitats in the regulation of hydrological flow and sediment control. We find that the forests and woodlands play a significant role in regulating sediment load in rivers and reducing peak flows, with implications for the water supply from the Ruvu River to Dar es Salaam and Morogoro. A cost-based value assessment under water treatment works conditions up to 2016 suggests that water supply failure due to deforestation would cost Dar es Salaam USD 4.6–17.6 million per year and Morogoro USD 308 thousand per year. Stronger enforcement of forest and woodland protection in Tanzania must balance water policy objectives and food security.

The influence of turbidity and water temperature on black fly species in the middle and lower Orange River, South Africa

Water clarity in the Orange River of South Africa alternates between highly turbid and clearer conditions. Multiple ecological effects result from this that affect aquatic community structure and species composition, including switching of dominant black fly species and growth of benthic algae. Fourteen sites in the middle and lower Orange River were sampled for black fly species and abundances, presence of benthic algae, and water quality and turbidity seasonally between November 2015 and December 2016. Logistic regression models, time series analyses, and multivariate ordinations showed that clearer water favours benthic algae and the minor pest black fly species Simulium adersi Pomeroy, 1922 and Simulium nigritarse Coquillett, 1902, while high turbidity favours the major pest black fly species Simulium chutteri Lewis, 1965 and Simulium damnosum Theobald, 1903. Moreover, these switches appear to be less frequent under post-impoundment conditions. We conclude that black fly species composition is dynamic and reflects changes in flow and turbidity levels. Flow regulation has resulted in a trade-off between improved water supply and ecological costs resulting from reduced ecosystem variability.

An inexact stochastic optimization model for multi-conflict regional water resources allocation in the south-to-north water benefited area

Abstract The cross-regional water diversion project has been widely applied as an important way to relieve water pressure. Study about the tradeoff between multiple regions and multiple water use sectors has caused widespread concern. In this study, an inexact two-stage water resources management model for multi-region water resources planning with a large-scale water diversion project has been developed. The water sources in 11 districts, including independent water sources and public water sources diverted from the project, are considered in the optimization model. Water supply cost and recourse cost are analyzed in the objective function. Based on interval-parameter programming and two-stage stochastic programming, uncertainties in the water resources system are described by both interval values and probability distributions. The result indicates that the water diversion project would greatly change the composition of the water resource system and settle the uneven distribution of regional water resources to achieve district-optimal allocation of water resources. In general, the proposed method can help decision-makers to formulate water management strategies for rational utilization of all kinds of water resources in different regions.

Modelling the water energy nexus: should variability in water supply impact on decision making for future energy supply options?

Abstract. Many countries, like South Africa, Australia, India, China and the United States, are highly dependent on coal fired power stations for energy generation. These power stations require significant amounts of water, particularly when fitted with technology to reduce pollution and climate change impacts. As water resources come under stress it is important that spatial variability in water availability is taken into consideration for future energy planning particularly with regards to motivating for a switch from coal fired power stations to renewable technologies. This is particularly true in developing countries where there is a need for increased power production and associated increasing water demands for energy. Typically future energy supply options are modelled using a least cost optimization model such as TIMES that considers water supply as an input cost, but is generally constant for all technologies. Different energy technologies are located in different regions of the country with different levels of water availability and associated infrastructure development and supply costs. In this study we develop marginal cost curves for future water supply options in different regions of a country where different energy technologies are planned for development. These water supply cost curves are then used in an expanded version of the South Africa TIMES model called SATIM-W that explicitly models the water-energy nexus by taking into account the regional nature of water supply availability associated with different energy supply technologies. The results show a significant difference in the optimal future energy mix and in particular an increase in renewables and a demand for dry-cooling technologies that would not have been the case if the regional variability of water availability had not been taken into account. Choices in energy policy, such as the introduction of a carbon tax, will also significantly impact on future water resources, placing additional water demands in some regions and making water available for other users in other regions with a declining future energy demand. This study presents a methodology for modelling the water-energy nexus that could be used to inform the sustainable development planning process in the water and energy sectors for both developed and developing countries.

A Holistic Concept to Design Optimal Water Supply Infrastructures for Informal Settlements Using Remote Sensing Data

Ensuring access to water and sanitation for all is Goal No. 6 of the 17 UN Sustainability Development Goals to transform our world. As one step towards this goal, we present an approach that leverages remote sensing data to plan optimal water supply networks for informal urban settlements. The concept focuses on slums within large urban areas, which are often characterized by a lack of an appropriate water supply. We apply methods of mathematical optimization aiming to find a network describing the optimal supply infrastructure. Hereby, we choose between different decentral and central approaches combining supply by motorized vehicles with supply by pipe systems. For the purposes of illustration, we apply the approach to two small slum clusters in Dhaka and Dar es Salaam. We show our optimization results, which represent the lowest cost water supply systems possible. Additionally, we compare the optimal solutions of the two clusters (also for varying input parameters, such as population densities and slum size development over time) and describe how the result of the optimization depends on the entered remote sensing data.

DESIGN OF PLUMBING SYSTEM AT TUNJUNGAN PLAZA APARTMENT, SURABAYA

Aim: This study of plumbing system plan is aimed at planning a plumbing system that is compatible with clean water, waste water and rain water management at Tunjungan Plaza apartment, Surabaya City, Indonesia according to SNI 8153-2015, and meet 5 aspects of safety, security, simplicity, beauty, and economy. It applies water supply system which commonly used for tall buildings, namely Roof Tank system. Methodology and Result: Plumbing system planning methods are collecting and analyzing fluctuation in water use, planning clean water and recycled water systems by endorsing alternative piping for clean water and recycled water. In addition to water supply, recycled water system that utilizes waste water to be recycled for flushing closets and watering plants also required to be implemented. Average daily water consumption is 268 m3/day for clean water and 44 m3/day for recycled water with the capacity of ground water tank for clean water is 564.54 m3 and recycled water is 62 m3. Conclusion, significance and impact study: Clean water supply system will implement roof tank system and recycled water will reutilize wastewater for flushing on toilet tank and watering the plants. Waste water use separated system between grey water and black water and then distributed to STP to be treated and reused for flushing water closet and watering plants. Rain water goes to infiltration well by gravity through designed 1 well. Total amount of investment of plumbing equipment is Rp 2,157,697,501,- with cost of water supply per unit Rp 4,445,643,- meanwhile waste water piping cost per units is Rp 1,070,711,-.

Comparing Contingent Valuation and Averting Expenditure Estimates of the Costs of Irregular Water Supply

We compare two methods—contingent valuation and averting expenditures—to measure the demand for improved water reliability in urban Jordan. Traditionally, averting expenditures (a revealed preference measure) have been considered a lower bound for demand relative to contingent valuation (a stated preference measure) estimates. We develop a theoretical model to show that this relationship critically depends on household perceptions. In our setting, this insight is important, because households appear to have relatively low confidence in both the reliability and quality of existing water supplies, even though water quality tests suggest that utility water is safe to drink from a microbial perspective. Averting expenditures, which reach 4% of monthly expenditures on average, include substantial purchases of non-network water sourced from water shops or tankers, as well as costs in terms of water collection time, storage and in-home treatment. In contrast, the contingent valuation responses, while correlated with coping costs, reveal low willingness to pay for increases in water reliability from the utility network. We attribute this departure from the traditional relationship between averting expenditures and contingent valuation to the lack of household confidence in the quality of utility-provided water. Our study thus adds to previous evidence in the literature, which points to the importance of consumer perceptions in determining demand for environmental improvements.

Long-Term Managed Aquifer Recharge in a Saline-Water Aquifer as a Critical Component of an Integrated Water Scheme in Southwestern Florida, USA

Managed Aquifer Recharge (MAR) systems can be used within the context of integrated water management to create solutions to multiple objectives. Southwestern Florida is faced with severe environmental problems associated with the wet season discharge of excessive quantities of surface water containing high concentrations of nutrients into the Caloosahatchee River Estuary and a future water supply shortage. A 150,000 m3/day MAR system is proposed as an economic solution to solve part of the environmental and water supply issues. Groundwater modeling has demonstrated that the injection of about 150,000 m3/day into the Avon Park High Permeable Zone will result in the creation of a 1000 m wide plume of fresh and brackish-water (due to mixing) extending across the water short area over a 10-year period. The operational cost of the MAR injection system would be less than $0.106/m3 and the environmental benefits would alone more than cover this cost in the long term. In addition, the future unit water supply cost to the consumer would be reduced from $1 to $1.25/m3 to $0.45 to $0.65/m3.

An intuitionistic fuzzy multi-objective non-linear programming model for sustainable irrigation water allocation under the combination of dry and wet conditions

Water scarcity causes conflicts among natural resources, society and economy and reinforces the need for optimal allocation of irrigation water resources in a sustainable way. Uncertainties caused by natural conditions and human activities make optimal allocation more complex. An intuitionistic fuzzy multi-objective non-linear programming (IFMONLP) model for irrigation water allocation under the combination of dry and wet conditions is developed to help decision makers mitigate water scarcity. The model is capable of quantitatively solving multiple problems including crop yield increase, blue water saving, and water supply cost reduction to obtain a balanced water allocation scheme using a multi-objective non-linear programming technique. Moreover, it can deal with uncertainty as well as hesitation based on the introduction of intuitionistic fuzzy numbers. Consideration of the combination of dry and wet conditions for water availability and precipitation makes it possible to gain insights into the various irrigation water allocations, and joint probabilities based on copula functions provide decision makers an average standard for irrigation. A case study on optimally allocating both surface water and groundwater to different growth periods of rice in different subareas in Heping irrigation area, Qing’an County, northeast China shows the potential and applicability of the developed model. Results show that the crop yield increase target especially in tillering and elongation stages is a prevailing concern when more water is available, and trading schemes can mitigate water supply cost and save water with an increased grain output. Results also reveal that the water allocation schemes are sensitive to the variation of water availability and precipitation with uncertain characteristics. The IFMONLP model is applicable for most irrigation areas with limited water supplies to determine irrigation water strategies under a fuzzy environment.

Conjunctive use of Inter-Basin Transferred and Desalinated Water in a Multi-Source Water Supply System Based on Cost-Benefit Analysis

Water shortage has forced coastal cities to seek multi-source water supply with a focus on inter-basin water and desalinated seawater. The differences of water supply costs pose a challenge in the optimal use of multiple water resources. This paper aims to understand the impact of desalinated seawater’s variable costs on multi-source water supply through a cost-benefit analysis method based on a multi-objective optimization model, considering different combination scenarios of desalination yield, streamflow condition, seawater desalting plant (SDP) scheme, water shortage index and utilization ratio of the SDP. The application in the coastal city Tianjin, China shows that the desalination yield has an impact on the tradeoff between the water shortage index and the total water supply cost and an optimal desalination yield can be determined at a turning point. And where the turning point appears is influenced by the utilization ratio of the SDP and streamflow conditions of inter-basin water. Moreover, a single centralized SDP is found to have an overall lower water supply cost than several decentralized small-sized SDPs. Lower water shortage index leads to higher cost, and the unit decrease of shortage index will need more added cost when the shortage index is very low. This method is proven to be effective in identifying the best conjunctive use of inter-basin water and desalinated seawater, which can contribute to relieve urban water shortage.

ESTABLISHMENT OF JET INDEX Ji FOR SOIL ERODIBILITY COEFFICIENTS USING JET EROSION DEVICE (JEd)

Soil erodibility has been identified as one of the major factors that govern threshold of resistance to erosion. Accurate measurement of soil erodibility in the field is indeed important for the determination of critical shear stresses. Critical shear stress is the stress that initiates particle movement that promotes shifting of the bankline. An attempt to establish soil erodibility parameters was successfully carried out using a newly fabricated Jet Erosion Device (JEd) based on soil properties. Soil erodibility coefficients are introduced to represent the erodibility of the soils under study. Statistical test is used to confirm the validity and accuracy of the proposed technique. Field data measurements were carried out on 3 rivers. Empirical models were developed using data from Selangor River and validated using data from Bernam and Lui rivers and other secondary river data. Analyses have shown high correlations and the parameters were further examined and analysed for the development of a predictive relationship for Ji. The most accurate model was selected based on the adjusted R2, standard error of the estimate and discrepancy ratio to illustrate its significance. Selection of the predictive variables was based on their ability to explain the variation of Ji. The models established could significantly reduce the cost, time and usage of water supply for field data collection using JEd.

Medium-term storage volume prediction for optimum reservoir management: A hybrid data-driven approach

A hybrid regressive and probabilistic model was developed that is able to forecast, six weeks ahead, the storage volume of Little Nerang dam. This is a small elevated Australian drinking water reservoir, gravity-fed to a nearby water treatment plant while a lower second main water supply source (Hinze dam) requires considerable pumping. The model applies a Monte Carlo approach combined with nonlinear threshold autoregressive models using the seasonal streamflow forecasts from the Bureau of Meteorology as input and it was validated over different historical conditions. Treatment operators can use the model for quantifying depletion rates and spill likelihood for the forthcoming six weeks, based on the seasonal climatic conditions and different intake scenarios. Greater utilization of the Little Nerang reservoir source means a reduced supply requirement from the Hinze dam source that needs considerable energy costs for pumping, leading to a lower cost water supply solution for the region.