The Water Infrastructure Simulation Environment (WISE) Project

Computational fluid dynamics (CFD) is a branch of fluid mechanics that uses numerical analysis and data structures to calculate, analyze, and visualize fluid (liquids, gases, and dissolved gases) flows. This document provides general introductions to best practices for CFD modeling in water infrastructure for practitioners, particularly those new to CFD modeling, which is becoming a widely used tool in the design and retrofitting of water, wastewater, and stormwater infrastructure. The method serves as an alternative, or complement, to physical modeling. In recent years, CFD has often been used in evaluating and troubleshooting existing water systems as well as improving future designs. As with the applications in other fields, the popularity of CFD in the water industry has been propelled by a multitude of factors including, but not limited to, the maturity achieved by CFD techniques, the development of stable and reliable numerical schemes, and the ever-improving computer-aided design (CAD) and meshing technologies for real-world complex geometries. This has been accompanied by many commercial and open-source CFD packages that can be run on increasingly more powerful computing hardware. Despite the visible progress in the application of CFD in water infrastructure projects achieved to date, there are still many challenges that hinder the widespread use of CFD techniques in water treatment design. Perhaps more important is that many of these challenges may result in misuse of the tool with dire consequences. It is imperative that CFD practitioners appropriately apply this tool without overpromising capability or accuracy and that reviewers of CFD model results know what to look for in ensuring proper methods have been applied and that results are representative of reality.

The climate is dynamic and constantly changing; it is projected to change more rapidly through the next 50 to 100 years. These predicted changes, while uncertain, are likely to increase failures of water, wastewater, and stormwater infrastructure due to extreme events if changes are not made during the planning and design of improvements and modifications required as systems reach the end of their useful lives. This study briefly outlines actual climatic changes that have occurred and recently published predicted changes. It looks at the impacts these changes will have on water, wastewater, and stormwater infrastructure and provides recommendations to assist engineers and owners who are working to address these impacts. In addition, cautions are provided relating to evaluating and using current climate data, models, and studies for planning and design purposes. While societal and socioeconomic factors also impact the design of water, wastewater, and stormwater infrastructure, this study only summarily covers those impacts associated with climate change.

Water is perceived to be one of the precious resources that should not be denied to any person; however, without the knowledge and attitude of how to sustain it, water will continue to be in short supply. This study aimed to contribute more knowledge about the perspectives on, the challenges of and the opportunities for water supply management in the Rustenburg Local Municipality, specifically in the township of Tlhabane, a small suburb of the municipality situated in North West province, South Africa. The problems leading to poor water supply and management that are experienced by various local communities were explored, with particular reference to Tlhabane township. A descriptive research design was used in this study and the researcher applied the qualitative research method because the two approaches are best used concurrently. The target population identified to respond to the research questions of this study were the community members of Tlhabane who have been facing great water-supply challenges. A probability sampling method was chosen in this study due to its ability to give every person an equal chance of being selected. A systematic random sampling technique was also used in this study, the researcher having determined a sample size of 300 as being sufficient to represent a subset of the Tlhabane community. The data were gathered by distributing open- and close-ended questionnaires to the community members. In addition, five unstructured interviews were conducted with the municipal staff members in the Directorate of Technical and Infrastructure (the Water Supply Unit). The study’s key findings reveal that the community members of Tlhabane expressed frustration at having unreliable access to water. This has led to a growing reliance on self-supply methods. An ageing water infrastructure (eg, asbestos-cement pipes) has led to frequent pipe leaks and bursts. High levels of water loss have been caused by inadequate pipeline maintenance, leading to community protests as a result of persistent water shortages. Limited financial resources have also hindered water infrastructure maintenance and upgrades. The water distribution infrastructure must be upgraded to reduce leaks and wastage. Public–private partnerships must be strengthened for better water management, community participation must be encouraged in water conservation efforts and alternative water sources such as recycled water and sustainable water-supply strategies must be leveraged. Recommendations are made that can be adopted to ensure good service delivery of water to the Tlhabane community. Once these measures are implemented, it is believed the water-supply problems will be overcome. These recommendations are meant to help the municipality to improve its water services to the community by eradicating water shortages. This will serve to ensure that there is economic well-being, employment, peace and stability in the area.

Recurrent incidences of pipeline failure bring about serious physical, economical, and environmental consequences. Therefore, developing pragmatic approaches to model the water distribution infrastructure is crucial for preserving these assets. The objective of this paper is to develop a pipe failure prediction model grounded in fuzzy inference system and the probability of failure analysis to estimate the rate of failure in water infrastructure. First, the attributes that contribute to water pipelines deterioration are identified. Second, the fuzzy logic engine is designed to simulate the defined codes and functions. Third, probability of failure schemes are generated to address the uncertainties and predict the risk associated with water pipes’ failure. The developed model was applied to the water network of the city of El Pedregal in Peru. This paper developed an automated tool, expected to improve the quality of decision making, as it can assist water utility managers and infrastructure engineers in optimizing their future plans.

The severe droughts of the 1990s made clear that the Strategic Plan of Zaragoza and the Action Plan of Local Agenda 21 in terms of water management were not appropriate to satisfy the development needs of its economy and the future demands of a growing population. In response, the city redefined its water management model, from one of continuous exploitation of resources to the search for solutions to reduce consumption. The city's efforts included a comprehensive programme of stakeholder involvement, rehabilitation of drinking water treatment and distribution infrastructure, improvement of water quality, and reform of the billing system. After 12 years, the city has managed to deduce its total consumption by nearly 30% and improve the quality of its water very significantly.

Smart meters for enhanced water supply network modelling and infrastructure planning

In many regions, conventional water supplies are unable to meet projected consumer demand. Consequently, interest has arisen in integrated urban water systems, which involve the reclamation or harvesting of alternative, localized water sources. However, this makes the planning and design of water infrastructure more difficult, as multiple objectives need to be considered, water sources need to be selected from a number of alternatives, and end uses of these sources need to be specified. In addition, the scale at which each treatment, collection, and distribution network should operate needs to be investigated. In order to deal with this complexity, a framework for planning and designing water infrastructure taking into account integrated urban water management principles is presented in this paper and applied to a rural greenfield development. Various options for water supply, and the scale at which they operate were investigated in order to determine the life‐cycle trade‐offs between water savings, cost, and GHG emissions as calculated from models calibrated using Australian data. The decision space includes the choice of water sources, storage tanks, treatment facilities, and pipes for water conveyance. For each water system analyzed, infrastructure components were sized using multiobjective genetic algorithms. The results indicate that local water sources are competitive in terms of cost and GHG emissions, and can reduce demand on the potable system by as much as 54%. Economies of scale in treatment dominated the diseconomies of scale in collection and distribution of water. Therefore, water systems that connect large clusters of households tend to be more cost efficient and have lower GHG emissions. In addition, water systems that recycle wastewater tended to perform better than systems that captured roof‐runoff. Through these results, the framework was shown to be effective at identifying near optimal trade‐offs between competing objectives, thereby enabling informed decisions to be made when planning water systems for greenfield developments.

Plants grown in porous media are part of a bioregenerative life support system designed for long-duration space missions. Reduced gravity conditions of orbiting spacecraft (microgravity) alter several aspects of liquid flow and distribution within partially saturated porous media. The objectives of this study were to evaluate the suitability of conventional capillary flow theory in simulating water distribution in porous media measured in a microgravity environment. Data from experiments aboard the Russian space station Mir and a U.S. space shuttle were simulated by elimination of the gravitational term from the Richards equation. Qualitative comparisons with media hydraulic parameters measured on Earth suggest narrower pore size distributions and inactive or nonparticipating large pores in microgravity. Evidence of accentuated hysteresis, altered soil-water characteristic, and reduced unsaturated hydraulic conductivity from microgravity simulations may be attributable to a number of proposed secondary mechanisms. These are likely spawned by enhanced and modified paths of interfacial flows and an altered force ratio of capillary to body forces in microgravity.

Water obviously play an importance role in our day to day life. Water distribution system is faced with myriads of challenges such as increasing water demand, limited resources, aging supply pipes that often result in water leakages. The supply of water could no longer fulfil the required demand of water supply with increase in the population of Ladoke Akintola University of Technology (LAUTECH). This study therefore examined water distribution in LAUTECH Ogbomoso campus. Primary and secondary data were used for this research. The primary data were sourced from registry, physical planning and work units of LAUTECH Ogbomoso, (8.13333⁰ N, 4.26667⁰ E), while the secondary data were from Global Positioning System (GPS) and google satellite imagery of LAUTECH campus. Field survey was conducted, from which the GPS point of each water source (Borehole) was obtained on the field. The study area has 14 boreholes and 3 wells, the distribution mains PVC pipes of diameter ranging from 50mm to 300mm. Spatial distribution of building with access to water and unmet water demand were determined. The secondary data were digitized using ArcGIS to produced variability map. The map showed that the water demand of each building per person was averagely estimated as 54.67 litres per day. The lowest water demand falls within 0-18 litre/day, while the highest falls within 391-2350 litre/day. The study revealed that the existing water distribution and infrastructure of LAUTECH is no longer sustainable.

Development and implementation of the Institutional Control Evaluation Project will include: Evaluate institutional surface water controls and infrastructure installed by LANL. Implement pilot project in the Los Alamos Canyon Watershed Spring, 2020. Initial evaluations will include canyon bottom controls with plan to expand program as funding allows. This will be a building block for successful Long-Term Monitoring and Stewardship (LTM&S) Program.

This guide is designed as an annotated checklist to aid local officials who are responsible for maintaining or restoring adequate sanitation in a widespread emergency. In the event of a major earthquake or nuclear attack, sewage collection and treatment systems, electric power and water treatment and distribution systems may be damaged or destroyed. Loss of sanitary sewage systems and water treatment capability sharply increases risk of the spread of disease among the survivors. The guide includes details of expedient methods of water disinfection, septic waste disposal, and disease vector control. Information on obtaining and using chemicals for these purposes is included. 3 tabs.

<div class="htmlview paragraph">Iodine depletion in a simulated water storage tank and distribution system was examined to support a larger research program aimed at developing disinfection methods for spacecraft potable water systems. The main objective of this study was to determine the rate of iodine depletion with respect to the surface area of the stainless steel components contacting iodinated water. Two model configurations were tested. The first, representing a storage and distribution system, consisted of a stainless steel bellows tank, a coil of stainless steel tubing and valves to isolate the components. The second represented segments of a water distribution system and consisted of eight individual lengths of 21-6-9 stainless tubing similar to that used in the Shuttle Orbiter. The tubing has a relatively high and constant surface area to volume ratio (S/V) and the bellows tank a lower and variable S/V. The test apparatus was cleaned and filled with a 10 mg/L iodine solution prepared with distilled-deionized water. Sampling from the tank, coil, and the series of tubes was performed periodically, and the major iodine species were monitored to determine the rate of decay of iodine and its fate in the system.</div> <div class="htmlview paragraph">Results of this study show that the iodine demand of stainless steel was significant. Decay rates were higher than anticipated in tubing that had not been previously exposed to iodine. The iodine (I<sub>2</sub>) concentration in the tank contents decreased to less than 1 mg/L in 10 weeks, whereas none was detected in water from the tubes after 1 week. Also, trace metals were measured in the samples by graphite furnace atomic absorption spectrometry and found to increase with contact time. A subsequent attempt to passivate the inside surface of the tubing via a 4-hour soak with 30 mg/L iodinated water reduced the rate but did not eliminate iodine loss. Ramifications of these findings to the current Shuttle potable water system and the design of spacecraft water systems in general are discussed.</div>

<p>Water flow dynamics and hydraulic properties of the rhizosphere are influenced by the exudation of mucilage and microbial extracellular polymeric substances (EPS). Upon drying, mucilage becomes hydrophobic and it impacts the rewetting kinetics of the rhizosphere. The effect of deposited mucilage on rewetting depends on the spatial distribution of the hydrophobic structures, which is a result of the drying rate, soil texture and mucilage concentration. To predict the role of deposited mucilage on rewetting, we simulate the deposition and rewetting process using a morphological pore network model that takes into account the spatial distribution of pores sizes and hydrophobic and hydrophilic structures. We show that the simulated water distribution is controlled by the amount, size and connectivity of the deposited material. The simulated water distribution is compared to neutron imaging experiments conducted in soils with different mucilage content. Comparison of simulations and measurements reveals the governing mechanisms of mucilage deposition and its impact on the environmental conditions in the rhizosphere.</p>

This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Computational models of oil, gas, and water flow through porous reservoir rock are used in reservoir management to decide whether or not, and how, to develop and produce hydrocarbon reserves. The flow models have major impact on these decisions so their accuracy, cost, and speed is paramount. The accuracy of the flow models is strongly dependent on the accuracy of the physical characterization of the reservoir rock`s pore-fluid system. System characterization is typically done in the laboratory. As an alternative, we have developed a numerical approach for determining the constitutive information. The project sought to use computational techniques that could incorporate all of the basic physical processes that influence fluid movement through the porous rock yet remain computationally efficient. The lattice Boltzmann (LB) numerical technique fits these requirements, and is able to incorporate complex pore geometries exactly and reproduce behavior of multiple fluids. The flexibility of the LB approach allows the numerical model, called the lattice Boltzmann Permeameter (LBP), to determine constitutive relationships (i.e., relative permeabilities) over a much wider range of conditions than can be achieved in a laboratory. Our project was directed toward improving the LBP to make it available to a wide range of users. Improvements were made in computational speed and efficiency, user interfaces, and visualization capabilities.

Utilities often do not know the actual condition of water distribution and transmission main infrastructure running under bodies of water or near/under critical infrastructure such as highways, railways and levees. These extensive and aging pipeline infrastructure assets often have no redundancy and in the event of a water main rupture pose very serious consequences in terms of environmental damage, service disruption and cost to repair surrounding infrastructure. A growing number of utilities are recognizing the need to inspect this critical infrastructure to minimize their risk exposure and ensure efficient water network operation. As part of their water network, the Corpus Christi Water Department operates a 24 diameter steel transmission main (a combination of cement lined steel and AC pipe) which runs under a shallow portion of the Corpus Christi Bay, connecting the main land to Padre Island which is a popular tourist destination featuring resorts, hotels, marinas, and pristine beaches. The transmission main was installed in 1960s and runs a total length of 24,000 feet under 4-8 feet of water/mud on the bay floor and throughout the island delivering potable water. There is currently no redundant water main to supply the island in the event of a rupture or service interruption. Due to the extensive cost to replace or repair the transmission main, the Corpus Christi Water Department required a reliable method to evaluate the condition of the pipeline to help make and justify their capital infrastructure plans and to ensure reliable water supply to the island.