Service Reservoirs Research Articles

Analysis of Circular Elevated Service Reservoir Using STAAD Pro by Considering the Effect of Continuity

In most regions of the country, early damage of elevated water tanks during their service life is becoming an increasing concern. The majority of damage occurs in tanks due to a lack of knowledge in design and ignoring continuity effect. Elevated water tank are used for storage of water at certain height and supplying water for essential usage. Hence damage of such structure endanger supply of drinking water and severe economical losses. The main purpose of this research is to determine the importance of continuity analysis in practical application and use of staadpro software to analyse an elevated circular water tank. The bottom joint of water tank is examined using continuity effect. This is the common joint where base slab, wall, bottom rings beam, gallery, column and base beam join. water tank is subjected to self-weight and hydrostatic Pressure due to water. Continuity effect increase stress, Hoop tension, BM hence its necessary to consider its effect while designing the tank. The results obtained from staadpro software is nearly same with manual result. This indicated that staadpro is suitable for design and analysis of water tanks. Three model having capacity of 55 m3, 125 m3 and 221 m3 situated in yavatmal, buldana and ramtek district is taken for analysis. Seismic analysis and wind analysis is also carried out on this model for safety purpose.

Seismic Analysis and Comparative Study of Elevated Storage Tank by GSDMA Guidelines

A container to store water in a huge amount of capacity can simply be called as the water tank. During the earthquakes, all these liquid storage tanks get collapsed or damaged heavily. 40 to 65 years is the feasible lifetime of an ESR in general. Shortage of drinking water, utilizing water, uncontrolled fires, etc are some unexpected events caused due to any damage or collapse of the tanks. Water tank parameters include various designs of tanks and different way of construction, materials, linings etc. Different materials are used for the construction and development of water tanks such as: - plastic, concrete, steel, fiberglass, etc. Therefore, to avoid all those unwanted events in the future various studies have been carried out regarding different types, shapes of water tanks. In this research, Elevated Service Reservoir (E.S.R) is being compared of shape Rectangular & Circular water tanks of capacity 5lakh litres and a total height of 18m with 3m, 4.5m staging height in Earthquake Zone V by Equivalent static analysis using STAAD.PRO software and referring GSDMA guidelines for the design of a tank and IS 1893 PART2-2014 code. By studying all the observations and results, it shows that Circular water tank is more preferable and economical for use.

Chlorine Decay Simulation in Water Distribution System Using EPANET

Chlorine is used as a disinfectant in the water treatment process so that treated water is delivered safely to consumers. However, chlorine concentration decays when water flows from the treatment plant to the supply point, due to the reaction with natural organic matter and the inner surface of the pipe. Low chlorine concentration may encourage bacteria re-growth, while high chlorine concentration can result in the formation of harmful chemical components. Therefore, this study aims to simulate the complex process of chlorine decay using EPANET. This exercise enables the determination the chlorine concentration dosage required to maintain the desired requirement given by the World Health Organization (WHO) and the Ministry of Health, Malaysia (MOH). A successful model with an extended period of simulations of 72 hours enable the mapping of spatial and temporal variations of flow and residue chlorine concentrations at all links and nodes. Constant chlorine dosage of 3.96 mg/l at node R1 has successfully satisfy the requirement given by WHO and MOH. The residue chlorine concentrations at the nodes and links in the water distribution system also depends on the water usage at node 5, the size of service reservoir and service tank and distance from the reservoir.

Comparative study of pressure variations in water distribution network due to change in location of elevated service reservoir

This paper compares the pressure variations in a water distribution system due to a change in the location of an elevated service reservoir with an intermittent type of supply for a continuously increasing demand. For this study Water Gems connect edition software is used for the design of a water distribution network. This study is conducted in the Eturnagaram habitation of Mulugu district. The Water Distribution Network is designed for 30 years with PVC as pipe material and intermittent type of supply. Further, this water distribution system is analyzed for pipe bursts and proposes a framework for the operation and maintenance of the water distribution network.

Analytical Study of Elevated Service Reservoir with Water Baffles Under Seismic Loading

Around the world earthquakes occur often causing some serious damages to property and life. Earthquakes weaken the structure and cause it to fail suddenly. Elevated Water tanks are such structures which have heavier mass suspended at a height supported on slender staging. When earthquake is induced in the tanks, it generates wave sloshing, the motion of the water induced due to seismic excitation. This sloshing of the water inside the tank will move in relative direction the seismic excitation causing structural instability. The water inside the tank will also act as tuned liquid mass damper and absorbs most of the energy created during seismic excitation. In this paper we have analysed various arrangement of baffle walls inside the tank in order to determine the stresses and displacements induced by the sloshing motion of the water tank. The water inside the tank will also act as tuned liquid mass damper where it will reduce the energy generated due to seismic excitation. During sloshing motion, there is an increase in lateral pressure applied over the tank walls which has adverse effect on the displacement of the system. The displacement of the system increases due to sloshing activity. By providing baffle walls we can reduce this displacement induced due to sloshing and thereby reduce the stresses generated on the supporting structure. From this analytical work the latter said was very evident.

System-wide joint-dynamic-response approach to water quality evaluation in distribution networks with multiple service reservoirs and pumps

Rigorous system-wide aggregated water quality performance indices for water distribution networks are lacking in the literature due to complexities associated with high dimensional spatial and temporal water quality data. Water quality considerations unavoidably increase performance evaluation difficulties considerably. The formulation developed in this article addresses the post-extended period simulation high-dimensional data challenges. A system-wide joint-dynamic-response approach to water quality evaluation is introduced that accounts for spatial and temporal variations in nodal demands and the respective time-varying hydraulic and water quality properties of multiple service reservoirs. Effective comparisons of the water quality response of service reservoirs and their effects were achieved. This includes individual reservoirs and the combined effects of multiple reservoirs. Service reservoirs and the nodes they supply were particularly vulnerable from the standpoint of water quality. The role of the network’s topology considering water quality risks was revealed also. The correlation between the medians and flow-weighted daily means of the water quality parameters was very strong (R2 ≥ 0.994) for the service reservoirs considered. Thus, the median could be useful as a practical performance surrogate in design optimization procedures. Finally, there seems to be an association between the flow-weighted daily means and overall hydraulic effectiveness of service reservoirs.

Cavern fire safety – overview of requirements and pragmatic solutions in Hong Kong

Hong Kong’s steep hilly terrain limits the growth of surface urban areas. In response to the society’s needs for land to support social and economic developments, the Government of Hong Kong Special Administrative Region is actively exploring the use of caverns as one of the innovative measures to supplement Hong Kong’s land resources. The development of cavern space is an attractive option to meet the land demand not only for “not-in-my-backyard” (nimby) type public utilities but also for a wide spectrum of uses including commercial, industrial and community type facilities. The development of cavern fire safety design in Hong Kong evolved from the first cavern project in around 1980s. The design guideline “Guide to Fire Safety Design for Caverns” was jointly established by Building Authority and Fire Services Department in 1994, by referring to overseas and local experience consolidated in the Study of the Potential Use of Underground Space (SPUN) in 1990. This guideline however was developed with a focus on caverns for use by low population public utilities such as sewage treatment works and water service reservoirs where the fire load is generally localised, closely controlled and relatively low. Whereas, other prescriptive fire safety guidelines commonly adopted in the Code of Practice for Fire Safety in Buildings 2011 (FS Code) and the Codes of Practice for Minimum Fire Service Installations and Equipment and Inspection, Testing and Maintenance of Installations and Equipment (FSI Code) were developed for typical surface buildings only. The existing fire design guidelines are found to be not fully compatible with the recent expanding spectrum of cavern usage in Hong Kong. Each cavern development type has its unique site setting and fire safety characteristics under the proposed usage (e.g. government facilities, industrial and commercial facilities like concrete batching/rock processing/asphalt production plants, data centres, logistics/warehouse facilities, etc.). Strictly following the prescriptive fire safety requirements and the design guidelines for typical buildings to these usages in cavern will pose immense technical issues/challenges to cavern projects and could also lead to unwarranted impacts on their functional operations. A more coherent fire safety design approach for new cavern projects is therefore needed to facilitate project proponents to plan cavern projects in the future. This paper provides an overview of fire safety issues for cavern development, and also discusses the practical solutions in formulating the associated fire safety strategies which have been adopted in the latest cavern projects in Hong Kong, covering the technical issues on fire resisting construction, means of escape, means of access for firefighting and smoke management.

Bacterial community including opportunistic pathogens dynamics in a chlorine tablet-dosed chloraminated service reservoir and reticulation pipes

This study reports even minimal changes of chloramine (measured as total chlorine) residual by chlorine tablets dosing in a service reservoir modify the bacterial community composition. The study was carried out by characterising the bacterial community composition in bulk water samples collected from the inlet, outlet, and downstream of a service reservoir. A regular dose of chlorine tablets to increase the chloramine by about 0.15 mg/L in the service reservoir increases total chlorine to ammonia nitrogen ratio and induces locally breakpoint chlorination within the proximity of the chlorine tablets. This, in turn, selects the specific bacterial groups despite smaller changes in the chloramine concentration. The dominated bacterial genera (87.1–93.8%) in the service reservoir were Methylobacterium and unclassified Rhizobiales whereas Methylobacterium, unclassified Rhizobiales, and Hyphomicrobium dominated (71.8–93.4%) downstream distribution pipelines of the service reservoir. E.Coli was not detected during the study period. Total chlorine residuals, nitrification, and temperature did not influence the presence/absence including the relative abundances of the majority of the opportunistic pathogens (characterized using the MiSeq Illumina platform). However, the presence of Burkholderia and Legionella increased at low total chlorine residuals and high temperatures in a small number of samples. Although this might indicate the importance of higher total chlorine residuals, more studies are needed to confirm if it is a valid strategy/or if there is health significance.

Appraisal of water quality indices for service reservoirs in water distribution networks.

The use of water quality indices to aggregate pollution loads in rivers has been widely studied, with researchers using various sub-indices and aggregation methods. These have been used to combine various quality variables at a sampling point in a river into an overall water quality index to compare the state of water quality in different river reaches. Service reservoirs in a water distribution network, like rivers, have complex mixing mechanisms, are subjected to various water quality variables and are variably sized and sited. Water quality indices and the relevant sub-indices are formulated here and applied to service reservoirs within a water distribution network. This is in an attempt to compare holistically the performance of service reservoirs in solutions of optimisation algorithms with regards to water quality.

Challenges in calibration of water distribution network: a case study of Ramnagar Elevated Service Reservoir command area in Nagpur City, India

Abstract Calibration of a hydraulic model is a challenging task as it considers the involvement of a large number of uncertain parameters. There are some parameters like length and diameter of pipes, for which fairly accurate values can be obtained. As with all hydraulic models, water demands are one of the main parameters that cause the most uncertainty in the model outputs. The calibration of the water demands is usually not feasible, which is attributable to the limited quantity of available measurements in most real water networks. However, some parameters like nodal demands and pipe roughness coefficients are estimated close to the actual values. Various types of valves are used for flow control by throttling. Hence, their setting in the field is also an important input to the model. Having more precise data helps in reducing time and results in better calibration as presented in the case study of one hydraulic zone served from Ramnagar Elevated Service Reservoir (ESR) (Zone II) in Nagpur City, Maharashtra State, India. This paper aims at presenting the complexities and challenges involved in calibration of the study area. It further describes the entire process from collection of the required data to the calibration of the network.

Application of enhanced assimilable organic carbon method across operational drinking water systems

Assimilable organic carbon (AOC) is known to correlate with microbial growth, which can consequently degrade drinking water quality. Despite this, there is no standardised AOC test that can be applied to drinking water distribution systems (DWDS). Herein we report the development of a quick, robust AOC that incorporates known strains Pseudomonas fluorescens strain P-17 and Spirillum strain NOX, a higher inoculum volume and enumeration using flow cytometry to generate a quicker (total test time reduced from 14 to 8 days), robust method. We apply the developed AOC test to twenty drinking water treatment works (WTW) to validate the method reproducibility and resolution across a wide range of AOC concentrations. Subsequently, AOC was quantified at 32 sample points, over four DWDS, for a year in order to identify sinks and sources of AOC in operative networks. Application of the developed AOC protocol provided a previously unavailable insight and novel evidence of pipes and service reservoirs exhibiting different AOC and regrowth behaviour. Observed correlations between AOC and microbial growth highlight the importance of monitoring AOC as an integral part of managing drinking water quality at the consumers tap.

War time damage at two London reservoirs

It is perhaps inevitable that major infrastructure installations become a target during wartime. While the ‘Dambusters raid’ was perhaps the most notable example of the Second World War, damage was also inflicted on a number of British dams during that conflict. The paper describes the experiences at two London water supply reservoirs, the Queen Mary, a large earth embankment storage reservoir and Honor Oak, a brick-arched roof service reservoir. The extent of the damage inflicted is described along with the emergency remedial works undertaken at the time as well as the longer term consequences.

Design and Analysis of Rural Water Supply System Using Loop 4.0 and Water Gems V8i for Nava Shihora Zone 1

The study presents the hydraulic design and analysis of Rural Water Distribution System (WDS) for Nava shihora region of zone 1 of the state of Gujarat, India. Water supply distribution system is designed for this study for population estimated for future 30 years. LOOP 4.0 and Water Gems v8i software have been used and the results are compared to determine the economical size of pipes for water distribution system. The economical size of pipes of water supply distribution system is designed by considering the constraints; residual pressure at each node, velocity of flow in pipe, head loos in pipes, material of pipes, elevated service reservoir level, peak factor and available commercial pipe diameters. Further water distribution system has been analyzed for extended period simulation (EPS) for the present population scenario for intermittent water supply using Water Gems v8i. Further water supply system is analyzed the residual chlorine concentration at nodes and in the pipe links and also the total cost of water supply system of rural region is estimated.

Seismic performance of existing water tank after condition ranking using non-destructive testing

There has been a collaborative attempt to address the seismic vulnerability of existing structures in India after an earthquake in Bhuj, Gujarat, in 2001. Seismic diagnosis and seismic retrofit for the existing tanks have become a remarkable issue to be worked since deterioration is a cosmopolitan and natural phenomenon. It is important to know the exact reason for distress and type of distress. To manage such issues, a proper method of repair and rehabilitation with detailed plans and methodology is required. This paper is aimed at evolving systematic investigation metrology for condition ranking procedure based on the analytical hierarchy process (AHP) and strengthening by various retrofitting strategies. For that case study, an existing elevated water tank is considered, which was designed according to state of the art over 40 years ago as per old Indian Standard (IS) code. The ranking assessment of the elevated service reservoir was carried out using different non-destructive tests (NDTs). DER, i.e., degree (D), extent (E) and relevancy (R) rating technique was employed to find out the condition index of the elevated service reservoir (ESR). After finding the condition ranking of the existing structure, an analysis was carried out using SAP 2000 to find the present-day seismic requirements using IS codes. After knowing the seismic demand of the water tank, various retrofitting methods were adopted for improving the drift capacity and flexural capacity of the structure. The results were finally used to address some of the critical issues of the seismic response of the retrofitted structure in terms of a time period, mode shapes, base shear, displacement, acceleration, and velocity. From the case study result of seismic retrofit for the existing elevated water tank, it is confirmed that a relatively simple seismic retrofit method is effective to keep the tank functional after an earthquake.

Water quality and anthropogenic impact in the watersheds of service reservoirs in the Brazilian semi-arid region

The semi-arid region of Brazil is characterised by the irregular temporal and spatial distribution of the rainfall, which together with anthropogenic action causes degradation of the water quality. The aim of this study was to evaluate water quality in surface reservoirs in the Brazilian semi-arid region due to rainfall variability and the degree of anthropisation of the watersheds. Water samples were collected at the Oros, Trussu and Muquem reservoirs during August and December of 2012, April, October and December of 2013, and March and June of 2014 (dry and rainy periods). The following limnological attributes were analysed: electrical conductivity, pH, turbidity, transparency and chlorophyll-a, with the results evaluated using box plots, and the mean values compared by Student’s t-test. Anthropogenic data from the watersheds contributing to the reservoirs were used to correlate limnological attributes with the condition of the watersheds during the dry period of 2013. The rainfall was not sufficient to significantly improve the water quality of the reservoirs, and in the Oros Reservoir high levels of chlorophyll-a and turbidity occurred during both periods. Anthropisation of these areas has a direct influence on the water quality of the surface reservoirs of the Upper Jaguaribe, showing a correlation with the attributes of water quality, especially with pH. Total degradation of the surface waters of the Upper Jaguaribe Basin due to land use in the watersheds is just a matter of time.

What lies beneath? A decade of underground construction in Hong Kong

Over the past decade Hong Kong has seen a rapid expansion in the use of underground space for Civil Engineering infrastructure projects (Fig. 1). Forty-eight kilometres of rail tunnel has been or is in the process of being constructed with associated shafts (Fig. 2) for access and ventilation and mined caverns for stations (Fig. 3). The catalyst for this expansion may be due to the integration of the Hong Kong Special Administrative Region with China, which commenced in 1997 (with the handing back of Hong Kong and the New Territories to China) and has accelerated over the last decade in line with the global aspirations of China. This integration has been the catalyst for three new major road border-crossing projects (Deep Bay Link; Hong Kong to Macau Bridge; and Liantang/Heung Yuen Wai crossing) and connection into the mainland express rail link (Hong Kong High Speed Rail Project) (Fig. 1). The population has also risen over this period from c. 6.9 million in 2005 to c. 7.3 million in 2016 (tradingeconomics 2016) fueling, in part, the expansion of mass transit rail systems: the Kowloon Southern Link (3 km – complete); the West Island Line (3 km – complete); Sha Tin to Central Link (17 km – under construction); the South Island Line East (7 km – under construction); the Kwun Tong Line extension (3 km – under construction) and the Hong Kong Express Rail Link (26 km – under construction) (Fig. 1). Pressure on valuable land resources has seen the emergence of the innovative use of underground space for: explosives magazines; sewage treatment systems; service reservoirs (Fig. 4); urban drainage and flood protection projects (Fig. 5); and new road networks, such as the Central–Wan Chai Bypass (Fig. 6). Fig. 1. Simplified outline map of the Hong Kong SAR showing the location of the projects referred to in this …

Evaluation of bacteriological and physicochemical quality of water supply systems in Welkite Town, Southwest-Ethiopia

Water supply systems provide consumers with drinking water that is adequately free of microbial pathogens to prevent waterborne diseases. The key to produce water of such desired quality is to implement multiple barriers, which control microbiological pathogens and chemical contaminants that may enter the water supply system. The objective of this study was to evaluate bacteriological and physicochemical quality of water supply system in Welkite Town, southwest Ethiopia. The water samples were examined on site for total coliform and thermo tolerant coliform using membrane filtration method. Raw water samples were positive for total coliform and thermo tolerant coliform, and there was high bacteriological load in Bojebar spring source which is total coliform: 16 cfu/100 ml, thermo tolerant coliform: 8 cfu/100 ml and in balancing reservoir, there was no detection for both total coliform and thermo tolerant coliform, whereas total coliform and thermo tolerant coliform were detected in the pipeline (counted as 6 and 1 cfu/100 ml, respectively). Similarly, in the service reservoir, the result indicated 9 and 1 cfu/100 ml for both total coliforms and thermo tolerant coliforms, respectively. On the other hand, temperature at all sampling sites was above the permissible limit set by World Health Organization but pH, electrical conductivity, turbidity, total hardness and total dissolved solids were all within the permissible limit set by World Health Organization. The free chlorine residual was 0.02, 0.84, 0.67, 0.48, 0.45 and 0.1 mg/l at six different sampling points, respectively, while the sanitary survey showed that cumulative risk score of all water supply systems was 27.2, 54.5, 90.09, 45.5 and 64% from the source to distribution, respectively. Key words: Bacteriological parameters, sanitary survey, total coliform, thermo tolerant coliform.

Calibration of water distribution network of the Ramnagar zone in Nagpur City using online pressure and flow data

Calibration of hydraulic model of a water distribution network is required to match the model results of flows and pressures with those obtained in the field. This is a challenging task considering the involvement of a large number of parameters. Having more precise data helps in reducing time and results in better calibration as shown herein with a case study of one hydraulic zone served from the Ramnagar Ground Service Reservoir in Nagpur City. Flow and pressure values for the entire day were obtained through data loggers. Network details regarding pipe lengths, diameters, installation year and material were obtained with the largest possible accuracy. Locations of consumers on the network were noted and average nodal consumptions were obtained from the billing records. The non-revenue water losses were uniformly allocated to all junctions. Valve positions and their operating status were noted from the field and used. The pipe roughness coefficients were adjusted to match the model values with field values of pressures at observation nodes by minimizing the sum of square of difference between them. This paper aims at describing the entire process from collection of the required data to the calibration of the network.

A new concept for using solar photovoltaic energy in urban water supply systems

Đurin, B., & Margeta, J. (November-December, 2017). A new concept for using solar photovoltaic energy in urban water supply systems. Water Technology and Sciences (in Spanish), 8(6), 47-61,DOI: 10.24850/j-tyca-2017-06-04. Solar photovoltaic (PV) systems can be applied very well to many areas of the water sector, such as urban water supply systems. This article presents an innovative methodology for using PV energy as a practical and sustainable solution for urban water supply systems. It presents a case study of the principal technological characteristics of an integrated energy-water system. The proposed solution consists of three parts: a PV generator and inverter, a service reservoir, and a pumping station. Given current trends, the proposed solution is slightly more expensive than conventional technologies. Nevertheless, the results obtained confirm the main idea of this research, which is that photovoltaic energy is a promising technology and provides a good solution for obtaining energy, in addition to being hydraulically sustainable urban water supply systems.

Geographical information system (GIS) application for planning and improvement of public water supply in Ota, Ogun State, Nigeria

Geographical information system (GIS) technique is a useful tool for spatial analysis which has not been fully exploited in solving water issues in Ota hence the study. The study applied the tool of GIS in the planning and improvement of water supply system in Ota, Ogun state. This study harnessed the synergy of GIS and engineering designs to proffer an acceptable solution to the problems of water supply in the study area. Primary data generated on the field with GPS and spatial information were analysed with the aid of GIS to produce contour pattern and Digital Elevation Model (DEM) in form of maps. The study noted that the population would increase to almost double the present population by the year 2040 invariably resulting to an increase in water demand of the population beyond the capacity of the existing water supply facilities. Results also showed that water demand by the projected population by year 2040 will increase to 68.37 million litres per day while the existing facility has the capacity to produce about 9.2 million litres per day. Maps produced by the study included Contour, Digital Elevation and Existing and proposed pipeline network maps. These maps made available more information which can then be used for improving the water supply system. The study proffered a lasting solution through design of water scheme with capacity large enough to cater for water requirement of the population for the next twenty-five years irrespective of variation in water need of individual residents in the area with designs to improve distribution system through extension of pipelines and identification of various locations for service reservoirs. Keywords : GIS, design period, per capita.