Top PDF Robust staged development of water supply systems

Robust staged development of water supply systems

Robust staged development of water supply systems

The long-term regional water supply (i.e. water resources management) problem is formulated here as a multi- objective optimization problem under uncertainty. The objectives are as follows: (a) the minimisation of the average present value (PV) of intervention costs; (b) the minimisation of the average present value (PV) of greenhouse gas (GHG) emissions; and (c) the maximisation of supply robustness. The uncertain variables are rainfall, per capita water consumption, population growth and discount rate Supply robustness is defined as the probability that water supply reliability (i.e. likelihood of water being fully supplied) and vulnerability (measured by supply/demand deficit) are simultaneously above and below pre-specified thresholds, respectively. The decision variables are the implementation stages and the sizes of some of the intervention options. The above problem is solved by using the NSGA-II optimisation method [3]linked to a WaterCress (Water-Community Resource Evaluation and Simulation System)simulation model [4]. Uncertain variables are sampled using the Latin Hypercube sampling (LHS) method. Computational efficiency is increased by using Artificial Neural Network (ANN) surrogate or metamodels, trained to calculate values of the objectives mentioned above. A multilayer perceptron (MLP) ANN architecture is used here.
Show more

6 Read more

Improvement of water quality and operational management of small water supply systems in rural area, South Korea

Improvement of water quality and operational management of small water supply systems in rural area, South Korea

In terms of water welfare equity and efficiency, small water facilities in rural areas lying in blind spots should be unified into a wide area and local water supply management system for unified management, water welfare administrative services in reliable, practical rural areas should be provided through the Continuous Performance Implementation (CPI) Strategy (Bereskie et al., 2017; Leclert et al., 2016) by the entrusted operation management system of specialized agencies with adequate technical skills to improve backward and aging facilities and improve water quality. With this study, the management of water quality can be strengthened by specialization of operation management, improvement of facilities and enhanced analysis management, reform of water intake and drainage management, and upgrade of awareness among the residents of use. Some local governments may seek to make up for the deficiencies of private consignment management in place and to be able to devise an efficient way to execute the budget. Based on the number of facilities and distribution status by region, a hub management system that integrates three to five cities and counties into one block can be operated to promote productive operation management. In particular, intensive control of substances that exceed drinking water quality standards by region-specific contaminants and geological background is required, and efforts to eliminate and treat contaminants through the development and dissemination of local custom underground water treatment technology (Kyung-seok et al., 2010). In addition, state budget support should be expanded for proper water quality maintenance and operation management.
Show more

12 Read more

Development of robust velocimeter for natural water flow monitoring

Development of robust velocimeter for natural water flow monitoring

Recently, demand for monitoring of river flow is becoming crucial to reduce or to prevent from flood disasters. Hence, a concept of instrument for river flow monitoring with self-power-supply was proposed by FELNUT utilizing the ring velocimeter, as shown in Figure 3 [5]. In the instrument, energy is harvested from vibration caused by the flow itself and the velocity measurement by a hot film in the ring velocimeter is replaced by drag force measurement to make it durable in natural river flow.

6 Read more

Genetic-Algorithms-Supported Planning of Water-Supply Systems

Genetic-Algorithms-Supported Planning of Water-Supply Systems

In order to demonstrate the genetic algorithm optimisation approach, the water-supply system of the town of Logatec was discussed. The system supplies around 7000 residents and a few industrial consumers. It can be placed among old systems, since some parts are older than 80 years. Due to different water sources (springs, wells) and stage development, the system is divided into three zones: high-pressure, middle-pressure and low- pressure parts. Through control devices (pressure reducing valves, pressure sustaining valves, etc.), the water can also be distributed from higher to lower zones.
Show more

17 Read more

Comparison of Methods of Pump Scheduling in Water Supply Systems

Comparison of Methods of Pump Scheduling in Water Supply Systems

storage requirements becomes excessive. It is for example not appropriate for pump optimisation systems with more than two reservoirs. Simulated annealing provides a sub-optimal result taking about 10 minutes to run with the pump optimisation problem. The development of an appropriate cost function is worth some consideration, and may lead to a better optimal result. Genetic algorithms are easy to use, but again it is the cost function, which presents the problem. The algorithm took approximately 20 minutes to run in this case.

7 Read more

On the importance of input variables and climate variability to the yield of urban water supply systems

On the importance of input variables and climate variability to the yield of urban water supply systems

The use of computational modelling is a critical element in the processes, practices, management and operation of urban water supply systems. However, uncertainty exists throughout all aspects of managing and modelling urban water supply systems, from the collection and handling of data, the interpretation of the physical system into a computational simulation, accuracy of future predictions, value of input variables, operation of the model, etc. This uncertainty propagates through the model to the model output: the yield. Following, this uncertainty in the estimation of yield will be instilled onto any management policies derived from the yield estimate. Although the exact realisation of yield is impossible to obtain (due to the variability that occurs from climate events and lack of knowledge of the optimal position of the system polices, rules and thresholds), certainty in its estimation can be improved by identifying highly influential input variables, and investigating and refining their knowledge. This will improve the confidence in the yield estimate and any management procedures and processes that consider it, leading to optimised system policy development and enforcement, augmentation studies, water sharing strategies and other decision-making practices, as well as an optimal target demand.
Show more

296 Read more

Sustainable Management of Small Water Supply Systems in Africa

Sustainable Management of Small Water Supply Systems in Africa

Funding for the regulation must preserve the independence of the regulator. In Mozambique, a 1% regulation fee should be paid to the local regulatory committee. In Mali, 1% of the operator’s turnover should be paid to the regulatory agency, but only for towns above 10,000 inhabitants. In Mali and Niger, the fee paid for business development services provided respectively by ‘STEFIs’ and ‘SACs’ operators include some regulatory activities. In most countries however, such arrangements are not yet implemented at scale and face practical obstacles due to geographical dispersion, impact on tariffs/access etc. There was consensus at the workshop that regulation can be partly funded from tariffs, but that some subsidy may also be needed.
Show more

16 Read more

Sizing of Domestic Rainwater Harvesting Systems Using Economic Performance Indicators to Support Water Supply Systems

Sizing of Domestic Rainwater Harvesting Systems Using Economic Performance Indicators to Support Water Supply Systems

Over the years, studies have shown that although rainwater harvesting is one of the most promising alternative water sources, their economic viability is not always assured owing to variability in user habits, climactic regions and local regulations [36,37]. Nevertheless, the environmental benefits of domestic rainwater tanks are enormous. Existing RWH systems are commonly focussed on the objective of conserving water without considering other potential benefits associated with them [14]. RRH systems no only assist in reducing the dependence on main water supply but also contribute towards drought preparedness in urban environments that are susceptible to dry climatic conditions. RRH systems also eliminate the need for water treatment at the end-use level by adopting a fit-for-purpose approach to water use, where the need for high quality water is not necessary for low health risk end-uses such as toilet flushing and gardening [38]. Urban development has dramatically changed the course of stormwater runoff during rainfall events. Urban domestic rainwater tank systems significantly reduce the stormwater runoff into nearby waterways [39], thereby moderating stormwater runoff impacts such as erosion of creeks and pollution of waterways. Further research based on other RRH system scenarios (with combinations of different end-use demands, roof area connectivity and tank sizes) may be beneficial for optimizing their configurations in future applications. This study has attempted to contribute towards improving the lack of high quality datasets associated with the multiple objectives of RRH systems, including water saving, stormwater management, energy consumption and greenhouse gas emissions that were identified by Campisano et al. [14] as needing further improved modelling studies.
Show more

16 Read more

The State and Needs of the Development of Water Supply and Sewerage Infrastructure in the Radzyń District

The State and Needs of the Development of Water Supply and Sewerage Infrastructure in the Radzyń District

investors and local governments to turn their at- tention to on-site wastewater treatment systems. The most commonly used domestic wastewater treatment solutions include: a septic tank with a drainfield, a septic tank with a sand filter, a mo- bile container wastewater treatment plant with activated sludge, a container sewage treatment plant with a biological filter bed, and a construct- ed wetland [Jawecki et al. 2015; Pawełek and Bugajski 2017]. To select the right technological system for the treatment of domestic wastewater one has to consider numerous technological, en- vironmental and economic factors, as well as the specific conditions that have an impact on sewage management in a given area [Karolinczak et al. 2015; Mucha and Mikosz 2009]. These include, among others: low water consumption per capita, highly variable wastewater inflow rates and pol- lutant loading rates, improper use of the sewer- age piping system, low temperature of sewage in winter, low quality of maintenance procedures, and lower reliability of sewage treatment plants [Mucha and Mikosz 2009 ].
Show more

9 Read more

MISSISSIPPI STATE DEPARTMENT OF HEALTH OFFICE OF HEALTH PROTECTION BUREAU OF PUBLIC WATER SUPPLY PUBLIC WATER SYSTEMS CAPACITY DEVELOPMENT PROGRAM

MISSISSIPPI STATE DEPARTMENT OF HEALTH OFFICE OF HEALTH PROTECTION BUREAU OF PUBLIC WATER SUPPLY PUBLIC WATER SYSTEMS CAPACITY DEVELOPMENT PROGRAM

The state is still seeing the effects of recent regulations such as the Ground Water Rule and Stage 2 Disinfection By-Products Rule with the additional difficulty some systems are having with compliance. As mentioned in previous year’s reports, new SDWA rules are an area where there is a special need for additional small system technical assistance. Currently, MSDH has contracts for the compliance challenges associated with the Ground Water Rule, the Disinfection By-Products Rule, and the State Fluoride Regulation. Furthermore, the Revised Total Coliform Rule could have a yet undetermined increased burden to public water systems once implementation begins, and this could affect water system capacity assessment. It is MSDH’s intention to provide assistance to ensure that non- compliance is kept to a minimum. MSDH discovered long ago that it is easier and less costly to help systems maintain compliance by providing targeted technical assistance than by attempting to bring a troubled system back in to compliance. We believe that the assistance has already had a profound effect on compliance rates, the capacity assessment program and water systems’ scores. Based on information from various sources, it appears that the water supply concepts of asset management and sustainable infrastructure will be a major part of future needs and requirements of water systems. Additional funding provided to the DWSRF program will allow for more specialized assistance in the previously mentioned areas of asset management planning or sustainable infrastructure to the water systems in the State. Furthermore, we believe the Board Management Training of officials of water systems of 10,000 population and less is having a positive impact on capacity assessment scores. It should also be noted that in the current economic climate, water systems are “doing their best” with less financial and operational resources. As economic conditions improve, many water systems may make significant infrastructure improvements that may be long overdue.
Show more

71 Read more

Economic and Financial Management of Small Water Supply Systems: Issue Introduction

Economic and Financial Management of Small Water Supply Systems: Issue Introduction

Professor Ben Dziegelewski and Mr. Tom Bik of Southern Illinois University conduct research on the economic and technical performance of water systems and the factors that seem to correlate with success in system management. Their paper reflects the results of a recent study that developed performance benchmarks for small public water systems in the Midwest. Information from a survey allows them to profile the infrastructure, finances, and management of small systems. We learn that 40% of the systems surveyed had no water treatment and another 10% reported chlorination only. Ground water was the major source of drinking water. Eighty percent of systems have some sort of supplemental water storage to maintain pressure and meet peak demands. Most systems (59%) reported an increase in the population served. Yet, 17% of systems reported total revenues that were less than total costs, and more than 35% of systems with less than 500 customers had no reserve fund. Additionally, 51% of these systems had not increased their water rates during the past five years. Dziegielewski and Bik recommend the development of case studies to demonstrate successful techniques for achieving sustainability including successful engagement of consumers, restructuring, and regionalization alternatives.
Show more

5 Read more

Development of a System Dynamics Computer Model for the Simulation of the Effects of an Alternate Water Source Development Project on the Water Supply Systems Management and Customer Satisfaction

Development of a System Dynamics Computer Model for the Simulation of the Effects of an Alternate Water Source Development Project on the Water Supply Systems Management and Customer Satisfaction

In this study, the effects of alternative water source development are evaluated by supplementing and expanding the System Dynamics (SD) computer simulation model developed for the simulation of the waterworks business by Park(2010). The data in KDI(2012) regarding the Nakdong riverbank filtration project feasibility study were used for the SD model developed in this study. Using the model long-term operational condition of Busan metropolitan city waterworks in South Korea was predicted in case Nakdong riverbank filtered water is supplied to Busan Metropolitan City. In addition, an index to quantify the overall satisfaction of the water supply service was developed and included in the SD modelling of this study.
Show more

8 Read more

Sustainability of rural water supply systems: assessment of gravity water systems implemented by Plan Cameroon in the
Northwest Province of Cameroon

Sustainability of rural water supply systems: assessment of gravity water systems implemented by Plan Cameroon in the Northwest Province of Cameroon

Bamali is part of the Ndop central subdivision in Ngeketunjia Division in the Northwest of Cameroon. The Ndop Plain is noted for their water problems, especially during the dry season. Since the community does not have the capabilities to solve their water problems, they decided in 1998 to send a request to Helevetas. Unfortunately they failed to raise the funds needed for the project. But it resulted in a feasibility study done by the government partner in the Ndop division for community development. Unfortunately governmental resources and capacity cut back so that the population had to finance these studies by themselves. When Plan entered Bamali in 2000 they handed these feasibility studies over to Plan. This resulted finally in a request from the community for financial and technical help from Plan, which has been approved by the country director of Plan Cameroon during November 2001. This led to several feasibility studies and a risk analysis on the management of the project by the community. It was decided that this project would be used as a pilot for Community Managed Projects (CMP’s). Due to problems like money transfer and contradicting feasibility studies the implementation of the first phase finally started in September 2002. Until then Plan had already been building up a history in the community; they have been providing mosquito nets, classrooms, pit toilets, school desks and scholarships for sponsored children among other things.
Show more

145 Read more

Auditing Water Management to Achieve Sustainable Development in Supply Chain

Auditing Water Management to Achieve Sustainable Development in Supply Chain

The study of [8] discusses the impact of Higher education on meeting the SD requirements .the research comes up with a number of conclusions most important of which is that the availability of lab devices, modern data show systems and audiovisuals in time of delivering lectures, financial allocations that are necessary to make research and develop and update curricula can contribute to enhancing higher education quality and achieving sustainable development in the supply chain. The problem of research that the Effective water management includes policies, procedures and programs to secure safe drinking water, suitable sanitation for all, efficient and sustainable use of water in all sectors, trans boundary international cooperation to protect human health and living organisms and securing the needs of current and future generations. Thus, the research problem is the lack of an audit report on water resources management that discloses the contribution of water management to the achievement of SDG 6 of post 2015 development Agenda as per SD (economic, social, environmental and institutional )dimensions. The research derives its importance through the following:
Show more

14 Read more

Fisher Information Methods for Detecting Shifting Regimes in Water Supply Systems.

Fisher Information Methods for Detecting Shifting Regimes in Water Supply Systems.

This research presented three methods for calculating Fisher information for time series data: an Amplitude-based Discrete Method with disjoint bins, an Amplitude-based Discrete Method with overlapping bins, and a Kernel Density Estimator method. Each method was compared against theoretical Fisher information for sets of normally distributed data. The amplitude-based methods show considerable deviations from the theoretical curve, whereas the kernel-based method deviates from the theoretical values, but follows the same general trend. The three methods were used to detect shifting regimes for two case studies for water supply systems: historic data was obtained to describe the Cantareira Reservoir System in São Paulo, Brazil, and an agent-based model was used to simulate data for Falls Lake in Raleigh, North Carolina. For the Brazil case study, each of the three Fisher information calculation methods detected two transition periods, during which the system re- organized and transitioned among states. Results from the three methods were not conclusive for the Raleigh case study. The Amplitude-based Discrete Method with overlapping bins generated highly variable Fisher information values that are difficult to interpret. The Amplitude-based Discrete Method with distinct bins and the Kernel Density Estimator Method performed similarly well to identify regime shifts. The two methods were tested for two climate change scenarios. While both methods identified regime shifts in periods where the storage data did not indicate any shift, the Kernel Density Estimator failed to detect a significant regime shift for one climate scenario. The development of the Amplitude-based Discrete Method with distinct bins provides an approach that can be easily implemented, generates output that can be more easily interpreted than overlapping bins, and detects regime shifts similar to the Kernel Density Estimator Method. For application to a large number of time series data sets, the Kernel Density Estimator Method generates output with distinct peaks to demarcate regime shifts. In this research, visual inspection is applied to identify shifts, and further research is needed to develop methods that can automatically detect shifts.
Show more

65 Read more

Development of a framework to evaluate the hybrid water supply systems

Development of a framework to evaluate the hybrid water supply systems

Abstract: Centralized water services in many major cities are increasingly being considered to be inadequate in achieving important goals for the urban water sector. It has been argued that new approaches need to be considered in order to cater for additional demand due to increasing population, changing climate, limited resource availability and a desire to protect ecosystems and build more livable cities. It has therefore been argued that providing additional capacity by using only conventional centralized systems is not economically or environmentally the best option. The use of decentralized water supply options such as rainwater tanks; storm water harvesting and reuse; and localized wastewater treatment and reuse in combination with centralized systems can help provide a sustainable solution to address these challenges by reducing the load on fresh water and decreasing the amount of wastewater to receiving environment. It is currently unknown how such technologies impact on the operational performance of the downstream infrastructure and existing treatment processes. For instance, reuse of greywater reduces the wastewater flow and hence there will be more change of solid deposition in the sewerage system. A comprehensive literature review has identified several significant research gaps related to interactions between centralized and decentralized water supply services. One of the prominent gaps is the effects of such hybrid water supply systems (combination of centralized and decentralized systems) on changes in the quantity and quality of wastewater and storm water of the existing system. Therefore, research is necessary to assess the feasibility of their implementation in conjunction with existing centralized systems. Prior to implementing these hybrid water supply systems (WSS), the interaction of these systems with the local environment needs to be understood.
Show more

7 Read more

Multi-Agent Approach to Biofilm Development in Water Supply Systems

Multi-Agent Approach to Biofilm Development in Water Supply Systems

Biofilm is a complex structure of the microorganism communities that develop in the presence of water, adhered to surfaces and coated by a protective layer segregated by themselves. Thus, the biofilm’s bacteria are capable of withstanding biocides and antibiotics more effectively than the free- living bacteria, supporting significantly higher doses of antimicrobial. Apart from the health risk that these communities of microorganisms represent in WSSs due to their role as pathogens reservoir, their presence in these systems is also associated with many other negative aspects that favour the decay of water quality in the distribution systems. In fact, biofilm is responsible for many of the problems encountered in these systems. The most prominent are: aesthetic deterioration of water [1], proliferation of higher organisms [2], operational problems [3], increased corrosion rates [4] and consumption of disinfectant [5].
Show more

9 Read more

Planning for robust water supply system investments under global change

Planning for robust water supply system investments under global change

improving the water resource planning process in the UK and to reflect trends in current water planning policy developments in the UK and worldwide. The challenge of long- term human-natural resource system planning is to identify high value portfolios of human interventions whilst considering the two main challenges: future deep uncertainty and multiple concurrent societal goals. This identification process is severely complicated by the exponentially large number of alternative combinations of schemes available to manage future resources. This research project demonstrates how simulating systems under multiple plausible realizations of the future coupled with ‘many-objective’ optimization can provide decision makers with robust solutions. Visual analytics is used to interact with results and demonstrate the benefits of this approach compared to traditional planning practices. Results presented here aim to aid water resources planners to orient investment strategies to meet key requirements and aspirations. These include but are not limited to maintaining the supply-demand balance and customer satisfaction in future, promoting sustainable use of resources, protecting the natural environmental, etc. The thesis aims to communicate to planners the increase in understanding of how such aspirations can be balanced taking into account
Show more

174 Read more

Regional development of public water supply systems

Regional development of public water supply systems

service for more North Carolinians at lower costs.. A regional approach to water supply also has potential disadvantages. One possible disadvantage of regionalization is the loss of reve[r]

152 Read more

Robust optimization methodologies for water supply systems design

Robust optimization methodologies for water supply systems design

high water residence times. The 2nd strategy, which is in- novation proposed in this work, can also be viewed as an alternative for existing WSSs. For some existing systems, strengthening the infrastructure links may be di ffi cult if it involves construction works in urban areas and it could also be prohibitively expensive, so innovative strategies should be used. For future developments of this work, consideration of the water age can be added to the determination of solutions. The water quality could be used to evaluate the design al- ternatives so that the solution can be further optimized for a truly robust design. It could also be important to under- stand the influence of the maintenance costs of many pump- ing stations required as contingence infrastructures in large systems, which is likely the case in real water systems. A life cycle cost analysis of the strategies (including the main- tenance of pipes and pumps) can be conducted to choose the design of a robust solution.
Show more

7 Read more

Show all 10000 documents...