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Apeldoorn, Netherlands

Blokker E.J.M.,KWR Watercycle Research Institute | van Osch A.M.,Gemeente Almere | Hogeveen R.,De Rookamer 6 | Mudde C.,Vitens
Journal of Water and Climate Change | Year: 2013

The municipality of Almere is planning to develop a new carbon neutral neighbourhood. The area is located close to a treated water storage facility. By extracting enough thermal energy to provide 900 homes with energy for space heating and heating tap water, the temperature of the treated water is lowered by 1.16 WC. This could lead to an increase in the energy required to heat water for domestic purposes. The temperature of tap water is influenced by the temperature of the soil surrounding the drinking water distribution system. The rate at which the water temperature will reach the soil temperature depends on the pipe material, the pipe diameter and the flow velocity. With the help of a network model, the effect of a lower initial water temperature on every customer in Almere was determined. On average, all 75,000 connections would receive slightly cooler water. The energy to heat the extra 0.125 WC is equivalent to the energy required to heat approximately 85 homes. As the extracted thermal energy enables heating of 900 homes, the energy balance is very positive. © IWA Publishing 2013.

Van Vossen-Van Den Berg J.,KWR Watercycle Research Institute | Blokker E.J.M.,KWR Watercycle Research Institute | De Graaf B.,Vitens
Procedia Engineering | Year: 2015

Regulatory sampling programmes have a fairly small chance of detecting contamination events in the drinking water distribution network. Sensors have the ability to measure more frequently and recent advancements in microbial sensor technology allow for faster detection. Using a hydraulic model of an actual network it is shown that even small sensor networks have a far better chance of detecting contamination events than regulatory sampling programmes. This allows for more effective response strategies by drinking water companies, thereby reducing the health risk of potential faecal contaminations. © 2015 Published by Elsevier Ltd.

Scruton S.R.,Thekwini Water and Sanitation | Bosboom J.,Your Man on Site | Fijma A.,Vitens
29th International No-Dig Conference and Exhibition 2011, NO-DIG BERLIN 2011 | Year: 2011

This paper discusses the decision variables to be evaluated for the rehabilitation of water mains, considering the performance of the network, the economic and technical lifespan of the mains and different available trenchless technologies in comparison to 'open trench' methodology. Water mains have a natural rate of attrition and they deteriorate over time. All Water Utilities / Municipalities in South Africa have been mandated by the National Government to efficiently manage their assets. The replacement of pipes is the most expensive intervention and therefore it is critically important to ensure that the correct water mains are targeted for renewal or rehabilitation and with the right available technology. To do this a number of key performance indicators need to be monitored on a permanent basis and these are determined by the specific requirements of the Water Utility. The rehabilitation or renewal of these assets can thus be reliably predicted to maximize the benefits and adequate budget can be allocated. Co-funded by the Dutch Government, eThekwini Water and Sanitation have committed themselves to do a comprehensive pilot study to compare different rehabilitation techniques on technical, operational, economic, and socio-economic aspects. Importantly, the research will also determine the measures to be undertaken to extend the life of an existing water main and thereby delay the date when the main will need to be replaced. It will further document the specific variables to be assessed in determining when a water main needs to be renewed or rehabilitated and with which technology. The outcome of this research will greatly enhance the ability of Water Utilities to maximize the performance of their networks by striking the best balance between capital and operational expenditure whilst taking into account the requirements of risk of failure and the cost of the rehabilitation / replacement.

Bakker M.,Technical University of Delft | Bakker M.,Royal HaskoningDHV B.V. | Trietsch E.A.,Vitens | Vreeburg J.H.G.,Wageningen University | And 2 more authors.
Water Science and Technology: Water Supply | Year: 2014

Pipe bursts in water distribution networks lead to water losses and a risk of damaging the urban environment. We studied hydraulic data and customer contact records of 44 real bursts for a better understanding of the phenomena. We found that most bursts were reported to the water company shortly after the beginning, and the negative consequences of the bursts were limited. However, smaller bursts that stayed unnoticed for a longer time period or larger bursts that began in the late evening or in the night were problematic to the water company that had no burst detection method installed. Detection of those bursts was critical to minimise the negative consequences, and a burst detection method could perform this task. We studied the relation between the size of supply area and the size of the bursts that can be detected. Therefore, we applied a heuristic burst detection method on historic datasets of eight areas varying in size between 1,500 and 48,300 connections. We found a correlation between the size of the area and the minimum detectable burst size and quickly detectable burst size. To reduce the risk of substantial water losses or damage to the urban environment, the burst detection method can effectively be applied to areas with an average demand of 150 m3/h or less. © IWA Publishing 2014.

Trietsch E.,Vitens | Jacobs B.,Vitens | Gielens S.,Vewin | Van Den Boomen M.,Colibri Advies
World Environmental and Water Resources Congress 2011: Bearing Knowledge for Sustainability - Proceedings of the 2011 World Environmental and Water Resources Congress | Year: 2011

The evacuation of inhabitants and an economic loss of at least 2 million Euros in 2004 were the result of a burst in a small water main, located in the dike of an inland canal. This incident was investigated on the highest level by the Dutch Safety Board. Several combining factors like descending of the dike, stress built up in the concrete protection sleeve and corrosion of the main eventually caused the subsidence of the dike. The Board emphasized to the drinking water companies the need of a management system for external safety. To prevent reoccurrence, Vewin, the Association of the Dutch Water Companies, together with the Dutch drinking water companies, have developed a methodology to measure and support the implementation of a safety management system. Furthermore, an approach was developed and implemented to identify external safety risks of mains which cross or lie parallel to primary dikes, primary motorways and railways. On a national level, 3,044 primary locations were identified where potential unsafe situations might exist This article describes the methodologies which are illustrated by the practical experiences of Vitens, the largest drinking water company in the Netherlands. © 2011 ASCE.

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