Network design for water quality monitoring of surface freshwaters: a review

To date, many water quality monitoring networks for surface freshwaters have been rather haphazardly designed without a consistent or logical design strategy. Moreover, design practices in recent years indicate a need for cost-effective and logistically adaptable network design approaches. There are many variables that need to be included in a comprehensive yet practical monitoring network: a holistic appraisal of the monitoring objectives, representative sampling locations, suitable sampling frequencies, water quality variable selection, and budgetary and logistical constraints are examples. In order to investigate the factors which affect the development of an effective water quality monitoring network design methodology, a review of past and current approaches is presented.     

Water–energy–greenhouse gas nexus of urban water systems: Review of concepts,state-of-art and methods

Water supply and wastewater services incur a large amount of energy and GHG emissions. It is therefore imperative to understand the link between water and energy as their availability and demand are closely interrelated. This paper presents a literature review and assessment of knowledge gaps related to water–energy–greenhouse gas (GHG) nexus studies in an urban context from an ‘energy for water’ perspective. The review comprehensively surveyed various studies undertaken in various regions of the world and focusing on individual or multiple subsystems of an urban water system. The paper also analyses the energy intensity of decentralized water systems and various water end-uses together with the major tools and models used. A major gap identified from this review is the lack of a holistic and systematic framework to capture the dynamics of multiple water–energy–GHG linkages in an integrated urban water system where centralized and decentralized water systems are combined to meet increased water demand. Other knowledge gaps identified are the absence of studies, peer reviewed papers, data and information on water–energy interactions while adopting a ‘fit for purpose water strategy’ for water supply. Finally, based on this review, we propose a water–energy nexus framework to investigate ‘fit-for-purpose’ water strategy.     

A process integration approach to industrial water conservation: a case study for a Chinese steel plant

A systematic approach to optimizing water network has traditionally been utilized to exam and plan water conservation in industrial processes. In the present case study, water-pinch technology was used to analyze and optimize the water network of a steel plant near China's Zhangjiakou city. A system design was developed and a limiting constraint (Cl(-) concentration) was identified based on investigations of water quality then the minimum freshwater and wastewater targets were determined without considering water losses. The analysis was then extended by calculating the additional input of freshwater required to balance the actual water losses. A nearest-neighbor algorithm (NNA) was used to distribute the freshwater and recycled water among each of the plant's operations. The results showed that with some reconstruction of the water network, the flow rates of freshwater and wastewater could be decreased by 57.5% and 81.9%, respectively.     

GOAL-ORIENTED AGRICULTURAL WATER QUALITY LEGISLATION1

ABSTRACT: While significant nonpoint source (NIPS) pollution control progress has been made since passage of Section 319 in the 1987 Water Quality Act, existing federal legislation does not provide for the most timely and cost-effective NIPS pollution reduction. In this paper, we use findings from the Rural Clean Water Program and other nationwide agricultural NIPS pollution control programs, building on legislative history to recommend a coordinated and efficient direction for agricultural water quality legislation. A collaborative framework should be established to accomplish the goals of the Clean Water Act (CWA), Coastal Zone Management Act (CZMA), and the Conservation Title of the Farm Bill. Valuable elements of the 1990 CZMA amendments that created a coastal NIPS program should be subsumed into the CWA. The CWA should reemphasize use of receiving water quality criteria and standards and should allow states flexibility to tailor basin-scale NPS program implementation to local needs. Implementation should involve targeting of NIPS pollution control efforts to critical land treatment areas and use of systems of best management practices to address these targeted water quality problems. The 1995 Farm Bill should reorient production incentives toward water quality to support the collaborative framework, implementing ecologically sound source reduction principles. The Farm Bill and the CWA should contain interrelated provisions for voluntary, incentive-assisted producer participation and fallback regulatory measures. Such coordinated national water quality and Farm Bill legislation that recognizes the need for flexibility in state implementation is supported as the most rational and cost-effective means of attaining water quality goals.     

A multiobjective optimization framework for multicontaminant industrial water network design

The optimal design of multicontaminant industrial water networks according to several objectives is carried out in this paper. The general formulation of the water allocation problem (WAP) is given as a set of nonlinear equations with binary variables representing the presence of interconnections in the network. For optimization purposes, three antagonist objectives are considered: F(1), the freshwater flow-rate at the network entrance, F(2), the water flow-rate at inlet of regeneration units, and F(3), the number of interconnections in the network. The multiobjective problem is solved via a lexicographic strategy, where a mixed-integer nonlinear programming (MINLP) procedure is used at each step. The approach is illustrated by a numerical example taken from the literature involving five processes, one regeneration unit and three contaminants. The set of potential network solutions is provided in the form of a Pareto front. Finally, the strategy for choosing the best network solution among those given by Pareto fronts is presented. This Multiple Criteria Decision Making (MCDM) problem is tackled by means of two approaches: a classical TOPSIS analysis is first implemented and then an innovative strategy based on the global equivalent cost (GEC) in freshwater that turns out to be more efficient for choosing a good network according to a practical point of view.     

China's water scarcity

China has been facing increasingly severe water scarcity, especially in the northern part of the country. China's water scarcity is characterized by insufficient local water resources as well as reduced water quality due to increasing pollution, both of which have caused serious impacts on society and the environment. Three factors contribute to China's water scarcity: uneven spatial distribution of water resources; rapid economic development and urbanization with a large and growing population; and poor water resource management. While it is nearly impossible to adjust the first two factors, improving water resource management represents a cost-effective option that can alleviate China's vulnerability to the issue. Improving water resource management is a long-term task requiring a holistic approach with constant effort. Water right institutions, market-based approaches, and capacity building should be the government's top priority to address the water scarcity issue.     

An Interval-Parameter Waste-Load-Allocation Model for River Water Quality Management Under Uncertainty

A simulation-based interval quadratic waste load allocation (IQWLA) model was developed for supporting river water quality management. A multi-segment simulation model was developed to generate water-quality transformation matrices and vectors under steady-state river flow conditions. The established matrices and vectors were then used to establish the water-quality constraints that were included in a water quality management model. Uncertainties associated with water quality parameters, cost functions, and environmental guidelines were described as intervals. The cost functions of wastewater treatment units were expressed in quadratic forms. A water-quality planning problem in the Changsha section of Xiangjiang River in China was used as a study case to demonstrate applicability of the proposed method. The study results demonstrated that IQWLA model could effectively communicate the interval-format uncertainties into optimization process, and generate inexact solutions that contain a spectrum of potential wastewater treatment options. Decision alternatives can be generated by adjusting different combinations of the decision variables within their solution intervals. The results are valuable for supporting local decision makers in generating cost-effective water quality management strategies.     

NATIONAL WATER ASSESSMENT: NEEDED OR NOT?1

ABSTRACT A conceptual framework and the systematic collection of reliable information for application within the framework are the cornerstones of effective water planning. The ideal of strengthening these cornerstones was a driving force behind formation of the Water Resources Council and Council efforts, during its life, to develop the Principles and Standards and to complete two National Water Assessments. The Assessments contained voluminous data but never really became an integral component of the national water planning process. Before being disbanded in 1982, the Council solicited several appraisals of its assessment process. This paper reports one made by the university community in which experiences and opinions were obtained from 108 water research administrators and water policy experts.     

Integrating economic and biophysical data in assessing cost-effectiveness of buffer strip placement

The European Union Water Framework Directive (WFD) requires Member States to set water quality objectives and identify cost-effective mitigation measures to achieve "good status" in all waters. However, costs and effectiveness of measures vary both within and between catchments, depending on factors such as land use and topography. The aim of this study was to develop a cost-effectiveness analysis framework for integrating estimates of phosphorus (P) losses from land-based sources, potential abatement using riparian buffers, and the economic implications of buffers. Estimates of field-by-field P exports and routing were based on crop risk and field slope classes. Buffer P trapping efficiencies were based on literature metadata analysis. Costs of placing buffers were based on foregone farm gross margins. An integrated optimization model of cost minimization was developed and solved for different P reduction targets to the Rescobie Loch catchment in eastern Scotland. A target mean annual P load reduction of 376 kg to the loch to achieve good status was identified. Assuming all the riparian fields initially have the 2-m buffer strip required by the General Binding Rules (part of the WFD in Scotland), the model gave good predictions of P loads (345-481 kg P). The modeling results show that riparian buffers alone cannot achieve the required P load reduction (up to 54% P can be removed). In the medium P input scenario, average costs vary from ￡38 to ￡176 kg P at 10% and 54% P reduction, respectively. The framework demonstrates a useful tool for exploring cost-effective targeting of environmental measures.     

Impact of closed-loop network configurations on carbon footprints: A case study in copiers

Growing concerns about the environment make a supply chains’ eco-footprint increasingly important, presuming that footprints are a more effective (policy) instrument than those currently in use. The eco-footprint comprises all kinds of environmental impact, but often is narrowed down to one aspect; e.g. the carbon footprint, material footprint, the water footprint, and so on. Although returns give rise to an additional goods flow from customers back to producers, it usually improves the eco-footprint due to the substitution effect. The reverse channel supplies high quality (recovered) products, components and materials to the forward channel thereby reducing the need for virgin sourcing and production. We refer to this as closed-loop recovery, as opposed to recovery for cascade markets which lacks substitution. To maximize substitution, the recovered items must re-enter the original supply chain. The feasibility of closed-loop recovery depends partly on the geographical proximity of forward and reverse facilities. We develop a decision framework for optimizing closed loop network configurations, i.e. the combined disposition and location–transport decision. We apply the framework to a single case study concerning one type of footprint (namely the carbon footprint) of a copier (closed-loop) supply chain. The main implication is that a regional network, with combined forward and reverse facilities per continent, proves most efficient and most robust in view of uncertain exogenous variables, but only when a full set of closed-loop options is available (including closed-loop recycling). As an embedded case, main contribution value of it lies in the discovery of a new phenomenon with generic implications; namely that not only the closed-loop supply chains footprint strongly depends on the substitution effect, but that in turn the feasibility of closed-loop recovery options depends heavily on the network design. From delineations of the study we derive issues for further research.     

Taking advantage of storm and waste water retention basins as part of water use minimization in industrial sites

A methodology for water use minimization has been developed by the Clean Technology Network of Bahia over a 10 year period in joint cooperative programs with the chemical, petrochemical and copper metallurgy industries located in the largest Industrial Complex in Latin America, in Camaçari, Bahia, Brazil. The methodology comprises a set of tools including reconciled aqueous stream balances, database of aqueous streams; large scale training leading to the identification of water minimization alternatives in the processes, water reuse optimization approaches; geographical information systems as well as, consideration of the region's hydro and hydro-geological characteristics. The results of a study carried out to assess the possibility of using storm and wastewaters for industrial use is presented in this paper. The inorganic system is composed by three water reservoirs (basins) receiving stormwater contaminated with inorganic effluents, and occasionally with organics. These basins have been operated to control water flow inputs according to the capacity of the pumping outlet systems before their discharge to a submarine outfall. A mass balance was performed with historical updated data to assess water availability from the basins based on the daily volume variation and flow rate of inorganic effluent from 2001 to 2007. The study identified the possibility of recovering about 1140 m³/h of the overall 5400 m³/h consumed by the Industrial Complex at the moment. Organizational changes in the present effluent disposal and stormwater harvest systems will be required in order to maximize water recovery for industrial use.     

A multi-objective optimisation approach to water management

The management of river basins is complex especially when decisions about environmental flows are considered in addition to those concerning urban and agricultural water demand. The solution to these complex decision problems requires the use of mathematical techniques that are formulated to take into account conflicting objectives. Many optimization models exist for water management systems but there is a knowledge gap in linking bio-economic objectives with the optimum use of all water resources under conflicting demands. The efficient operation and management of a network of nodes comprising storages, canals, river reaches and irrigation districts under environmental flow constraints is challenging. Minimization of risks associated with agricultural production requires accounting for uncertainty involved with climate, environmental policy and markets. Markets and economic criteria determine what crops farmers would like to grow with subsequent effect on water resources and the environment. Due to conflicts between multiple goal requirements and the competing water demands of different sectors, a multi-criteria decision-making (MCDM) framework was developed to analyze production targets under physical, biological, economic and environmental constraints. This approach is described by analyzing the conflicts that may arise between profitability, variable costs of production and pumping of groundwater for a hypothetical irrigation area.     

Result-oriented approaches to the management of drinking water catchments in agricultural landscapes

Management of water quality in drinking water catchments is of ongoing, high importance as nitrate concentrations are often still very high. We analysed the Augsburg catchment in Germany, a unique example where a result-oriented approach has been implemented. We investigated the historical evolution of the water protection programme, the result-oriented payment contracts with farmers, and farmer satisfaction with the contracts, based on interviews with the water utility and farmers as well as an analysis of the literature. Today, the water protection programme has been successfully implemented, and a significant reduction of nitrate concentration was achieved due to the following factors: (1) investment of non-negligible amounts of money for high compensation and remuneration payments, (2) different contract options, (3) farmers’ participation in the negotiation process for result-oriented payment contracts, (4) involvement of “outside” people and institutions in negotiation processes, (5) anticipation of starting a programme when nitrate levels were still far below legislative thresholds, and (6) a political and legislative framework allowing direct decisions by a water supplier.     

Efficient and Practical Approaches to Ground‐Water Right Transfers Under the Prior Appropriation Doctrine and the Snake River Example1

Abstract: Water right transfers are one of the basic means of implementing changes in water use in the highly appropriated water resource systems of the western United States. Many of these systems are governed by the Prior Appropriation Doctrine, which was not originally intended for application to ground‐water pumping and the conjunctive management of ground water and surface water, and thus creates an administrative challenge. That challenge results from the fact that ground‐water pumping can affect all interconnected surface‐water bodies and the effects may be immeasurably small relative to surface water discharge and greatly attenuated in time. Although we may have the ability to calculate the effects of ground‐water pumping and transfers of pumping location on surface‐water bodies, mitigating for all the impacts of each individual transfer is sufficiently inefficient that it impedes the transfer process, frustrates water users, and consequently inhibits economic development. A more holistic approach to ground‐water right transfers, such as a ground‐water accounting or banking scheme, may adequately control transfer third‐party effects while reducing mitigation requirements on individual transfers. Acceptance of an accounting scheme can accelerate the transfer process, and possibly reduce the administrative burden.     

Watershed-based point sources permitting strategy and dynamic permit-trading analysis

Permit-trading policy in a total maximum daily load (TMDL) program may provide an additional avenue to produce environmental benefit, which closely approximates what would be achieved through a command and control approach, with relatively lower costs. One of the important considerations that might affect the effective trading mechanism is to determine the dynamic transaction prices and trading ratios in response to seasonal changes of assimilative capacity in the river. Advanced studies associated with multi-temporal spatially varied trading ratios among point sources to manage water pollution hold considerable potential for industries and policy makers alike. This paper aims to present an integrated simulation and optimization analysis for generating spatially varied trading ratios and evaluating seasonal transaction prices accordingly. It is designed to configure a permit-trading structure basin-wide and provide decision makers with a wealth of cost-effective, technology-oriented, risk-informed, and community-based management strategies. The case study, seamlessly integrating a QUAL2E simulation model with an optimal waste load allocation (WLA) scheme in a designated TMDL study area, helps understand the complexity of varying environmental resources values over space and time. The pollutants of concern in this region, which are eligible for trading, mainly include both biochemical oxygen demand (BOD) and ammonia-nitrogen (NH3-N). The problem solution, as a consequence, suggests an array of waste load reduction targets in a well-defined WLA scheme and exhibits a dynamic permit-trading framework among different sub-watersheds in the study area. Research findings gained in this paper may extend to any transferable dynamic-discharge permit (TDDP) program worldwide.     

Seeking calm water: Exploring policy options for India's water future

This paper seeks to identify some promising policy options which could be part of a strategic and holistic effort to address India's future water challenges. Significant increases in agricultural water productivity would be a major factor in reducing the need for developing new water sources. Crop diversification, appropriately targeted to account for the present agricultural systems and available water resources, will increase productivity. Furthermore, much more emphasis needs to be placed on effective management of the groundwater resources through renewed efforts to enhance artificial recharge and conservation. Also, efforts should be revived to improve the existing surface irrigation systems. In particular, systems could be reconfigured to provide a more reliable water supply and allow effective community level management, where appropriate. Finally, while some of the increasing demands from domestic and industrial users will be met by the development of groundwater and reallocation of water from the agricultural sector, this will not be sufficient. Given that such conditions are emerging in states with high economic growth and relatively water scarce basins, this will require the further development of water resources. In some cases, these conditions along with the demand for reliable water for high value crops, will be part of the justification for inter‐basin transfers.     

Building the role of local government authorities towards the achievement of the human right to water in rural Tanzania

In recent decades, many changes have occurred in the approach to financing and operating water services in developing countries. The demand‐responsive approach is now adopted in many countries in a context of donor‐supported decentralization processes, which gives more responsibility to end users. However, the government's responsibility at different levels is enforced by the international recognition of the human right to water. This paper examines specific actions that build the role of local government authorities in this scenario. A collaboration between an international NGO and a rural district in Tanzania from 2006 to 2009 is used as an action research case study that is representative of local capacity‐building needs in decentralized contexts and rural areas. Three main challenges were detected: i) lack of reliable information; ii) poor allocation of resources in terms of equity; and iii) lack of long‐term community management support from the district. Two mechanisms were established: i) water point mapping as a tool for information and planning; and ii) a District Water and Sanitation Unit Support (DWUS) for community management. The results show how the framework provided by the goal of human right to water helps to define useful strategies for equity‐oriented planning and post‐project support at the local level.     

以苛性法软化油田采出水用作锅炉给水的处理新工艺

在应用蒸汽开采重油（稠油）生产中，常因采出水不需回注而带来环境保护上的问题。较适宜的处置方法是将采出水处理后作为发生蒸汽的锅炉给水。而软化具高矿化度的采出水使其符合硬度指标要求极为严格的锅炉用水，是处理工艺中关键技术之一。本文对美国当前在这方面的一般处置方法作了综合性介绍，着重介绍了Belridge油田水软化处理厂采用苛性法和弱离子交换法这一新工艺的成功经验。     

Sustainable Water Resources Management in a Conflict Resolution Framework1

Abstract: A decision support system for sustainable water resources management in a water conflict resolution framework is developed to identify and evaluate a range of acceptable alternatives for the Geum River Basin in Korea and to facilitate strategies that will result in sustainable water resource management. Working with stakeholders in a “shared vision modeling” framework, sustainable management strategies are created to illustrate system tradeoffs as well as long‐term system planning. A multi‐criterion decision‐making (MCDM) approach using subjective scales is utilized to evaluate the complex water resource allocation and management tradeoffs between stakeholders and system objectives. The procedures used in this study include the development of a “shared vision model,” a simulated decision‐making support system (as a tool for sustainable water management strategies associated with water conflicts, management options, and planning criteria), and the application of MCDM techniques for evaluating alternatives provided by the model. The research results demonstrate the utility of the sustainable water resource management model in aid of MCDM techniques in facilitating flexibility during initial stages of alternative identification and evaluation in a basin suffering from severe water conflicts.