Not even one percent of the water on earth is available as fresh drinking water. Still, as the infrastructure of most water-distribution systems is aging, a lot of precious liquid is lost on the way to the customer. But modern sensor-technology in Smart Cities can help put our water infrastructures into a better shape.
■ by Rainer Classen
Especially in areas that are subject to regular bouts of drought, the loss of water due to leakages in the pipe-system can cause serious problems. But even where there is no real shortage of fresh water, the economic damage due to ineffective maintenance is often huge.
In the past, experts in the area of pipe-control have attempted to analyze the condition of the water main simply by listening to the sounds from the pipes and with the help of a tool similar to a doctor’s stethoscope. But even well trained employees are not always able to tell exactly where a crack has occurred by this method. This means high costs to dig up culverts to find leaks.
However, with the help of new technology and predictive maintenance methods, water suppliers in Europe and the U.S. are finally solving the seepage problem.
“Be like water making its way through cracks” – these are the first words of a famous quote of martial-arts legend Bruce Lee. A man, whose ability to control his body is unsurpassed. Examples for intelligent water distribution will continue and be implemented in many other places, we will be able to have better control over the flow of waters in our civilization. Thus being able to effortlessly guarantee higher efficiency, less pollution and more quality of life to the people.
Plugging the hole
Existing equipment is unable to detect leaks in plastic water pipes with any accuracy or consistency. Severn Trent – a big water supplier in England – uses the LeakFinderST developed by the Canadian company Echologics to check for leakage. The system makes leak detection a lot easier – and it can find leaks other systems are unable to detect. Keiron Maher, research and development manager of Severn Trent, believes that “this is a fantastic piece of kit that significantly reduces the amount of time needed to accurately locate leaks, especially in plastic pipes. This is great news for us and our customers, as more and more of our pipes are plastic now, because we’re upgrading and replacing the old metal pipes. And this new technology will help us in our quest to drive down levels of leakage.”
LeakFinderST enables municipalities to locate “quiet” narrow band, low frequency leaks and leaks previously identified as background leakage on water mains, with materials such as plastic, concrete or cast Iron.
The system uses the correlation method to notice leakages and to locate them exactly (see caption below). Developed and patented in collaboration with Neil Dixon and James Flint, electronic engineers from Loughborough University, Echologics acquired a license to incorporate the technology into their next generation of leak detection products. The system received the Outstanding Innovation Award at the UK’s Water Industry Achievement Awards last year.
A disadvantage of the system used in Severn Trent is that leakages can only be detected where you look for them. The mobile teams equipped with Echologics need to attach smart sensors to hydrants all across town to find cracks. A leak may stay unnoticed as long as the teams do not make measurements nearby.
In Dortmund, Germany. 600.000 people rely on DEW21, the local water company, for their water supply. In 2014 they installed a system with fixed sensors at 109 measuring points in their water net which stretches over 350 kilometers. The sensors make recordings during nighttime, when noise disturbance is comparatively low. The data is transmitted wirelessly to the analysts at DEW21. If they can hear an increase of the lowest noise level, chances are that there is a leak. If no fixed sensors are available to detect the precise position of the leak, service teams with mobile loggers do a closer examination of the area.
The illustration from manufacturer SebaKMT (right) shows how the correlation method is used to locate the exact position of a leak. If two sensors are near the leak, its precise location can be calculated from the different times it takes for the noise to reach the two sensors. The information is transferred to cloud servers or directly to the service station of the water company. Depending on the location of the sensors and the material of the pipes, the location of a leak can be detected very precisely. With this method leaks can be detected at a very early stage, which makes it easier to repair the damage, and as service teams know exactly where to look the costs of digging up the streets are lower, too.
Water companies not only take care of the water supply; they also need to make sure that wastewater is being cleaned and returned in a natural cycle.
In Bordeaux, the French company Suez has installed a smart water remote-control center called RAMSES (Régulation de l’Assainissement par Mesures et Supervision des Equipements et Stations/Regulation of Sanitation by Measures and Supervision of Equipment and Treatment Plants) that utilizes data provided by the France weather forecast service, including rainfall measurements, RAMSES accurately determines the threat posed by heavy rain and thunderstorms in real time. The system is able to predict the location and volume of potential floods 24 hours ahead in dry weather, and six hours ahead in rainy weather. The system also provides a birdseye view of the entire sanitation system using meteorological, metrological, hydrological and hydraulic data.
This enables authorities to prevent flooding or overflow of retention systems. But RAMSES can do even more: It ensures that surface water can be stored using the capacities of a wide range of existing sanitation infrastructures such as pumping stations, main sewers, and surge ponds. The system makes sure that these infrastructures are fully utilized by means of dynamic management of incoming water and by redirecting the movement of water towards available infrastructures until the network resumes its usual flow, thus creating an economic and financial solution which makes best use of storage capabilities at the right place and at the right time.
Support from Brussels for Smart Cities
■ The ICeWaterproject
Municipalities are not always alone in their efforts to develop or aquire systems to increase the efficiency of their water distribution. In 2013 the ICeWaterproject was launched in Italy with funding from the European Union’s Seventh Framework Programme.
The project is hosted by a consortium of companies including the Rumanian water supplier Aquatim, along with Toshiba and Siemens who conducted studies aimed at increasing the stability of freshwater supply to citizens in urban areas by adjusting the water supply to the actual consumption, thus minimizing energy use through smart-grid integration, as well as reducing water losses through leak detection. In a pilot-project in the center-south of Milan several steps were taken to move closer to the intelligent town of the future. A decision support system using advanced simulation and optimization algorithms and cloud computing was installed. Benefits included
- planning of the water supply system with respect to operational and strategic aspects
- energy reduction and water quality control
- intelligent water waste and consumption reduction system that supports leak detection and water spill with a “fix before break” approach
- a water demand management system that is highly adaptive and supports dynamic pricing for water asset management
- networking components, service infrastructure and communication platform for interconnecting all subsystems
The ICeWater project took three years to complete and went operational in October 2015. Final results haven’t been published yet, but the project operators are sure many communities will profit from this smart cities pilot project since it proves how important information and communication technology will become in the field of water supply.
Water Cycle Management in Valencia, Spain
In Spain, the Institute of Computer Technology (ITI) uses a system called PRETESIC that was developed in collaboration with the Polytechnic University of Valencia (UPV) and Telefonica Cathedra. It was recently deployed in the city of Valencia and monitors water quality by measuring a wide range of environmental parameters. The main advantage is the system’s ability to reduce the time needed to deploy a wireless sensor network.
Networks such as these are called Quick Deployment Sensor Networks (QDSN). The nodes use Waspmotes, an open source wire less sensor platform specially focused on the implementation of low consumption modes, making the sensor nodes (“motes”) completely autonomous. Parameters are measured and transferred to Unit Control via the Internet, including
- Oxidation and reduction “redox”
- Chemical oxygen demand
The system can react to unexpected situations, avoiding possible damage from natural disasters such as floods. One of the main advantages is that PRETESIC allows deployment of sensor nodes almost anywhere, and the sensors can start to receive data immediately. In the near future systems like this will greatly increase the amount of information on the water circulation available to communities and water departments.
It’s always good to know the status of your water-net, of course. But when the information has to trigger a reaction, time is at a premium. The Berliner Wasserbetriebe, the company that supplies water to the German capital, recently installed a system called LISA (“Leit- und Informationssystem Abwasser” = Guide- and Information System for waste water) that controls 300 pump stations, rainwater reservoirs and other facilities all over the city and the surrounding areas. Status information is gathered centrally in this smart cities solution.
Circulation of wastewater is controlled remotely from the control center, too. During heavy rain, the flow of wastewater can be redirected to sewage works that still have free capacity remaining.