scholarly journals Optimal Sensor Placement and Leak/Burst Localisation in a Water Distribution System Using Spatially-Constrained Inverse-Distance Weighted Interpolation

10.29007/37cp ◽  
2018 ◽  
Author(s):  
Shaun Boatwright ◽  
Michele Romano ◽  
Stephen Mounce ◽  
Kevin Woodward ◽  
Joby Boxall
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Sensor Placement ◽  
Significant Risk ◽  
Inverse Distance Weighted ◽  
Search Area ◽  
Distance Weighted ◽  
The Impact ◽  
Inverse Distance

Water loss from water distribution systems (WDS) is an ongoing problem which poses a significant risk to water resources around the world. This paper presents a novel combined sensor placement – leak/burst localisation methodology which forms, and analyses by using sc inverse-distance weighted (IDW) interpolation, a sensitivity matrix to determine, on average, how accurately each sensor configuration localises leaks/bursts modelled at all nodes in a WDS. For a given number of sensors, the multi-objective evolutionary algorithm determines the optimal location of sensors to maximise the leak/burst localisation performance using the sc-IDW outputs in its objective function. Once the optimal sensor location is selected, the sc-IDW technique is used when new leaks/bursts occur in the WDS to determine their approximate location. A benchmark WDS was used to compare the leak/burst localisation performance against a baseline sensor placement technique. The comparison indicated that by using the sc-IDW technique for both the sensor placement and leak/burst localisation steps the leak/burst search area was reduced in size by between 9 and 26%. Reducing the leak/burst search area allows field teams to more quickly repair a leak/burst and reduce the impact that it has on water company operational efficiency and customer service.

Molecular characterization of bacteria inhabiting a water distribution system simulator

2003 ◽  
Vol 47 (5) ◽  
pp. 149-154 ◽  
Author(s):  
J.W. Santo Domingo ◽  
M.C. Meckes ◽  
J.M. Simpson ◽  
B. Sloss ◽  
D.J. Reasoner
Keyword(s):  
16S Rdna ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Heterotrophic Bacteria ◽  
Feed Water ◽  
Ammonia Oxidizing Bacteria ◽  
16S Rdna Pcr ◽  
The Impact

The objective of this study was to monitor the impact of chlorination and chloramination treatments on heterotrophic bacteria (HB) and ammonia-oxidizing bacteria (AOB) inhabiting a water distribution system simulator. HB densities decreased while AOB densities increased when chloramine was added. AOB densities decreased below detection limits after the disinfection treatment was switched back to chlorination. The presence of AOB was confirmed using a group-specific 16S rDNA-PCR method. 16S rDNA sequence analysis showed that most bacterial isolates from feed water, discharge water, and biofilm samples were α-Proteobacteria or β-Proteobacteria. The latter bacterial groups were also numerically dominant among the sequences recovered from water and biofilm 16S rDNA clone libraries. The relative frequency of each culturable bacterial group was different for each sample examined. Denaturing gradient gel electrophoresis analysis of total community 16S rDNA genes showed notable differences between the microbial community structure of biofilm samples and feed water. The results of this study suggest that disinfection treatments could influence the type of bacterial community inhabiting water distribution systems.

scholarly journals Near-optimal scheduling of device activation in water distribution systems to reduce the impact of a contamination event

2011 ◽  
Vol 14 (2) ◽  
pp. 345-365 ◽  
Author(s):  
S. Alvisi ◽  
M. Franchini ◽  
M. Gavanelli ◽  
M. Nonato
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Optimal Scheduling ◽  
Mixed Integer ◽  
Maximum Speed ◽  
Contaminated Water ◽  
Flow Control Devices ◽  
The Impact

This paper proposes an innovative procedure for identifying, in the event of accidental or intentional contamination of a water distribution system, the optimal scheduling of activation of a pre-selected set of flow control devices which will serve to minimise the volume of contaminated water consumed by users after the detection of the contaminant in the system. The constraints are represented by the number of available response teams and the maximum speed at which these teams can travel along the roadway. The optimal scheduling of device activation is sought by means of an optimisation process based on a genetic algorithm (GA) which interacts with a mixed integer linear programming (MILP) solver in order to ensure the feasibility of the scheduling identified. The optimisation procedure is coupled to a hydraulic and quality simulator, which enables a calculation of the volumes of contaminated water consumed by users, and a dynamic cache memory, which, by storing information on the system's behaviour as the optimisation process progresses, serves to limit the computational times. The application of the procedure to a highly complex real water distribution system shows that the optimisation process is robust and efficacious and produces a smaller volume of contaminated water consumed by the users than when the activation of all the devices was completed in the shortest amount of time.

scholarly journals Comparative analysis of different probability distributions of random parameters in the assessment of water distribution system reliability

2013 ◽  
Vol 16 (2) ◽  
pp. 272-287 ◽  
Author(s):  
Giovanna Darvini
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Network Reliability ◽  
Probability Distributions ◽  
Probabilistic Approach ◽  
Temporal Variations ◽  
Random Parameters ◽  
Statistical Parameters ◽  
The Impact

During recent years, several methods based on the probabilistic approach have been proposed for the analysis of the performance of water distribution systems (WDSs). Uncertain elements are described by probabilistic laws chosen and parameterised on the basis of the network characteristics. However, the choice of the most suitable probabilistic distribution and of the statistical parameters can be difficult because of the lack of information about the WDSs. Among the stochastic parameters that affect the network performance, a fundamental role is played by the times to failure and repair of the system components. The impact of the chosen probability distributions of these fundamental variables on the evaluation of water distribution network reliability is analysed. The study is performed by using a technique capable of considering the mechanical failure of the network components, the spatial and temporal variations of the water demand and the uncertain distribution of the pipe roughness. This analysis allows quantification of the effect of any inaccuracy that may occur in the probabilistic characterisation of the random parameters.

scholarly journals Assessing the impact of working pressure on water meter registration

2021 ◽  
Author(s):  
Isaac G. Musaazi ◽  
Jotham I. Sempewo ◽  
Mohammed Babu ◽  
Nicholas Kiggundu
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Supply Systems ◽  
Deterministic Models ◽  
Working Pressure ◽  
Sensitive Parameter ◽  
The Impact ◽  
Supply Systems ◽  
Water Meter

Abstract Fluctuations in the network pressure of water supply systems affect hydraulic performance and water meter accuracy. The development of metering error curves requires steady-state conditions which are extremely rare in water distribution systems characterized by intermittent supply. Simple deterministic models are suggested and developed from monthly data collected over a 4-year period (2010–2014) for three most dominant meter models (Models 1–3) in the Kampala Water Distribution System (KWDS), Uganda. This study combines pressure and billing information at the same time to understand metering accuracy. Results showed that metering accuracy increased by 4.2, 8.4 and 2.9% when pressure was increased from 10 to 50 m for Models 1–3, respectively. Age did not influence the impact of pressure on meter accuracy. The most sensitive parameter in the model was the meter age. Metering accuracy was relatively constant after a period of 5 years. The least sensitive parameter was the working pressure which caused a slight change to the annual billed volume. The ability of the model to accurately predict the meter registration degenerated with an increasing annual billed volume. Model 2 meters were the best performing and probably the most suitable meters in the KWDS.

scholarly journals The Impact of Pipe Material on the Diversity of Microbial Communities in Drinking Water Distribution Systems

2021 ◽  
Vol 12 ◽  
Author(s):  
Debbie Lee ◽  
Gennaro Calendo ◽  
Kristin Kopec ◽  
Rebekah Henry ◽  
Scott Coutts ◽  
...  
Keyword(s):  
Drinking Water ◽  
Cast Iron ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Pipe Material ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution ◽  
The Mean ◽  
The Impact

As many cities around the world face the prospect of replacing aging drinking water distribution systems (DWDS), water utilities must make careful decisions on new pipe material (e.g., cement-lined or PVC) for these systems. These decisions are informed by cost, physical integrity, and impact on microbiological and physicochemical water quality. Indeed, pipe material can impact the development of biofilm in DWDS that can harbor pathogens and impact drinking water quality. Annular reactors (ARs) with cast iron and cement coupons fed with chloraminated water from a municipal DWDS were used to investigate the impact of pipe material on biofilm development and composition over 16 months. The ARs were plumbed as closely as possible to the water main in the basement of an academic building to simulate distribution system conditions. Biofilm communities on coupons were characterized using 16S rRNA sequencing. In the cast iron reactors, β-proteobacteria, Actinobacteria, and α-proteobacteria were similarly relatively abundant (24.1, 22.5, and 22.4%, respectively) while in the cement reactors, α-proteobacteria and Actinobacteria were more relatively abundant (36.3 and 35.2%, respectively) compared to β-proteobacteria (12.8%). Mean alpha diversity (estimated with Shannon H and Faith’s Phylogenetic Difference indices) was greater in cast iron reactors (Shannon: 5.00 ± 0.41; Faith’s PD: 15.40 ± 2.88) than in cement reactors (Shannon: 4.16 ± 0.78; Faith’s PD: 13.00 ± 2.01). PCoA of Bray-Curtis dissimilarities indicated that communities in cast iron ARs, cement ARs, bulk distribution system water, and distribution system pipe biofilm were distinct. The mean relative abundance of Mycobacterium spp. was greater in the cement reactors (34.8 ± 18.6%) than in the cast iron reactors (21.7 ± 11.9%). In contrast, the mean relative abundance of Legionella spp. trended higher in biofilm from cast iron reactors (0.5 ± 0.7%) than biofilm in cement reactors (0.01 ± 0.01%). These results suggest that pipe material is associated with differences in the diversity, bacterial composition, and opportunistic pathogen prevalence in biofilm of DWDS.

scholarly journals A deterministic approach for optimization of booster disinfection placement and operation for a water distribution system in Beijing

2013 ◽  
Vol 15 (3) ◽  
pp. 1042-1058 ◽  
Author(s):  
Fanlin Meng ◽  
Shuming Liu ◽  
Avi Ostfeld ◽  
Chao Chen ◽  
Alejandra Burchard-Levine
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Real Life ◽  
Deterministic Approach ◽  
Study Results ◽  
The Impact ◽  
Beijing China

Previous studies on booster disinfection optimization were commonly based on ‘blank networks’, neglecting the impact of existing disinfection facilities, which could result in misleading solutions. To overcome this limitation, a method, which incorporates the existing disinfection facilities, is developed and demonstrated in this study. A particle backtracking algorithm, which traces the upstream pathways of the disinfection insufficiency nodes, is employed to narrow down the potential positions for booster stations. Deterministic optimization results are then efficiently yielded by the introduction of a ‘coverage matrix’. The proposed method is applied to a real life water distribution system in Beijing, China. Results show the methodology effectiveness in optimizing booster disinfection placement and operation for real life water distribution systems. For the explored case study, results suggest that adding a booster disinfection station at 0.1% of the nodes of the system can satisfy chlorine residual at about 97.5% of all nodes.

Biofilm formation potentials in drinking waters treated by different advanced treatment processes

2002 ◽  
Vol 2 (4) ◽  
pp. 97-104 ◽  
Author(s):  
S. Okabe ◽  
T. Kokazi ◽  
Y. Watanabe
Keyword(s):  
Water Treatment ◽  
Distribution System ◽  
Biofilm Formation ◽  
Distribution Systems ◽  
Water Distribution ◽  
Treatment Plant ◽  
Biological Activated Carbon ◽  
Treatment Processes ◽  
Biological Treatments ◽  
The Impact

When biodegradable organic matter and other nutrients, such as ammonia and phosphorus, are not sufficiently removed during water treatment, bacteria may proliferate in the water distribution system. Bacterial regrowth deteriorates water quality (taste and odor), accelerates corrosion, and potentially increases the risk of microbial diseases. Therefore, this research was conducted to evaluate the impact of four different advanced water treatment processes, including biological treatments such as a rotating biofilm membrane reactor (RBMR) and a biological activated carbon (BAC) filter and ultrafiltration (UF), on reduction of nutrient levels and biofilm formation potentials of the treated water entering model distribution systems (annular reactors). Our results revealed that biological treatments significantly improved the “biostability” of water leaving from the treatment plant. On average, The RBMR and BAC filter reduced easily assimilable organic carbon (AOC) concentration by half when compared with conventional treatment (multi-media filtration; MF) and ultrafiltration (from 35-49 to 18-23 mg C L-1). Consequently, biofilm formation potential was reduced by a factor of 5 to 10 (from 3,200-5,100 to 490-710 pg ATP cm-2). With respect to “biostability” of water, ultrafiltration was less effective in reducing AOC concentrations. In addition, the impact of chlorine disinfection on biofilm accumulation and AOC levels in the distribution system were studied.

scholarly journals Serious Sensor Placement—Optimal Sensor Placement as a Serious Game

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 68 ◽  
Author(s):  
Georg Arbesser-Rastburg ◽  
Daniela Fuchs-Hanusch
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Sensor Placement ◽  
Pressure Sensors ◽  
Serious Game ◽  
Optimal Placement ◽  
Placement Problem ◽  
Optimal Sensor Placement ◽  
Novel Approach

In this paper, we present a novel approach in water loss research combining two different topics: The optimal placement of pressure sensors to localize leaks in water distribution systems and Serious Gaming—games that are not only entertaining but that are also serving another purpose. The goal was to create a web interface, through which gamers could place sensors in a water distribution system model, in order to improve these sensor positions after they had been evaluated by a suitable algorithm. Two game objectives are to be pursued by the players: reaching a specified net coverage while not using more than a maximum number of sensors. For this purpose, an existing optimal sensor placement algorithm was extended and implemented, together with two hydraulic models taken from literature. The resulting Serious Game was then tested and rated in a case study. The results showed that human players are able to reach solutions that are similar regarding net coverage to those obtained by optimization, within in a short amount of time. Furthermore, it was shown that the implementation of the ideal sensor placement problem as a Serious Game motivates the players to get better and better results, while also providing them with an enjoyable gaming experience.

scholarly journals Application of genetic programming to modeling pipe failures in water distribution systems

2010 ◽  
Vol 13 (3) ◽  
pp. 419-428 ◽  
Author(s):  
Qiang Xu ◽  
Qiuwen Chen ◽  
Weifeng Li
Keyword(s):  
Genetic Programming ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Pipe Failure ◽  
Beijing City ◽  
Failure Data ◽  
Processing Strategies ◽  
Gis Data ◽  
Failure Models

The water loss from a water distribution system is a serious problem for many cities, which incurs enormous economic and social loss. However, the economic and human resource costs to exactly locate the leakage are extraordinarily high. Thus, reliable and robust pipe failure models are demanded to assess a pipe's propensity to fail. Beijing City was selected as the case study area and the pipe failure data for 19 years (1987–2005) were analyzed. Three different kinds of methods were applied to build pipe failure models. First, a statistical model was built, which discovered that the ages of leakage pipes followed the Weibull distribution. Then, two other models were developed using genetic programming (GP) with different data pre-processing strategies. The three models were compared thereafter and the best model was applied to assess the criticality of all the pipe segments of the entire water supply network in Beijing City based on GIS data.

scholarly journals The influence of distance weight on the inverse distance weighted method for ore-grade estimation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhan-Ning Liu ◽  
Xiao-Yan Yu ◽  
Li-Feng Jia ◽  
Yuan-Sheng Wang ◽  
Yu-Chen Song ◽  
...  
Keyword(s):  
Estimation Accuracy ◽  
Block Model ◽  
Minkowski Distance ◽  
Inverse Distance Weighted ◽  
Grade Estimation ◽  
M 10 ◽  
Weight Calculation ◽  
Distance Weighted ◽  
Inverse Distance ◽  
Ore Grade

AbstractIn order to study the influence of distance weight on ore-grade estimation, the inverse distance weighted (IDW) is used to estimate the Ni grade and MgO grade of serpentinite ore based on a three-dimensional ore body model and related block models. Manhattan distance, Euclidean distance, Chebyshev distance, and multiple forms of the Minkowski distance are used to calculate distance weight of IDW. Results show that using the Minkowski distance for the distance weight calculation is feasible. The law of the estimated results along with the distance weight is given. The study expands the distance weight calculation method in the IDW method, and a new method for improving estimation accuracy is given. Researchers can choose different weight calculation methods according to their needs. In this study, the estimated effect is best when the power of the Minkowski distance is 3 for a 10 m × 10 m × 10 m block model. For a 20 m × 20 m × 20 m block model, the estimated effect is best when the power of the Minkowski distance is 9.

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