Plugging Leakages

Utilities focus on reducing non-revenue water

Due to the rapid population growth and economic development in the country, Indian cities are facing a severe water crisis. In urban India, a significant quantum of water provided by service utilities remains unaccounted for owing to water thefts, illegal connections and leakages in the distribution system. In a bid to mitigate the issue, municipal corporations across the country are increasingly adopting technology solutions for easier and faster detection of leakages in water distribution pipelines. While some of these solutions, such as SmartBall® and Sahara®, are based on highly advanced leakage detection technologies, simpler and more conventional tools are also preferred by many civic agencies. In addition, utilities have adopted data collection and infrastructure mapping systems to facilitate leakage detection.

Smart Utilities takes a look at some of the prominent technologies currently deployed in water infrastructure in urban India…

Advanced leakage detection tools

SmartBall® technology

SmartBall® leak detection technology makes use of an advanced tool to identify leakages and air pockets in water supply pipelines. It is a ball-shaped and free-swimming device with a diameter of 150 mm. It is equipped with a sensitive acoustic sensor, which is capable of locating very small leaks, with water leakages as low as 0.028 gallon per minute. It can identify these leakage points within 6 feet of their actual locations.

To conduct inspections, the SmartBall® tool is inserted into a pipeline, which is at least 350 mm in diameter. It is equipped to travel with the water flow in the pipeline for up to 16-18 hours per deployment. Therefore, it can complete long surveys in a single deployment without causing any disruptions to the regular pipeline services.

Two access points need to be identified along the pipeline for deploying this sensor, one for insertion of the SmartBall® and the other for its extraction. The tool can be tracked throughout the inspection process by installing GPS or sensor meters at predetermined locations on the pipeline. This will help civic agencies get real-time data about the location of the SmartBall® and the portions of the pipeline that are affected by leakages and gas pockets.

Sahara® pipeline inspection system

The Sahara® system for pipeline inspection can be deployed for detecting leaks, air pockets, inline valves, branches, redundant and illegal connections, as well as structural issues such as corrosion, tuberculation, debris and partial blockages in waste and sewage mains. It comprises a drag chute device, a sensor head and a buoyant data cable. The drag chute and sensor head are inserted into a live pipeline network through existing air valves or meter taps, which have a diameter of at least two inches. The sensor head is propelled along the pipeline flow by the drag chute and can traverse horizontal and vertical bends in the pipeline without any issues. Using the attached data cable, the sensor can cover distances up to 6,000 feet per insertion. The data cable is disinfected before being inserted into the pipeline to avoid any possible water contamination.

Utilities can track the sensor through a precision locator known as the Sahara Locator. A technician uses it to follow the sensor head above ground. The locator is equipped with an extremely low frequency transmitter that is detected by the sensor inside the pipeline. This enables communication and accurate data collection through pipelines.

Tracking the Sahara® sensor plays a critical role in locating the acoustic anomalies in the network. It allows utilities to monitor and analyse data collected from the sensor in real time. The sensor can be stopped and sent back to inspect a detected leakage or anomaly. The Sahara system also provides acoustic signal processor software, which converts the audio signal from the sensor into a visual form and displays its signal amplitude, frequencies, head position and velocity. Further, the software allows the operator to distinguish between pipeline features, isolate acoustic anomaly locations and qualitatively estimate leak magnitudes.

The Sahara® system is capable of identifying water leakages that are as small as 0.005 gal per minute. It can be deployed in pipelines with a diameter of 250 mm or above, irrespective of the material of the pipeline. The data cable attached to the drag chute and the sensor head ensures full control of the device by inspection officials. Further, the device can be deployed for inspection without causing any disruptions in the regular pipeline flows. The surface tracking of the sensor also allows the utility to map the pipeline network with sub-metre accuracy.

Sahara® Video

Built on the Sahara® platform, Sahara® Video allows for the visual inspection of live pipeline conditions without the need of dewatering or costly shutdowns of pipeline networks. The solution comprises a CCTV camera and an LED light, which is installed on the Sahara® pipeline inspection device. The camera is propelled through the pipeline along with the sensor head and transmits real-time video data to the utilities.

Sahara® Video can help investigate a number of pipeline issues. For instance, it can be used for locating lost line valves, investigating pipeline flows and trapped gas pockets, identifying illegal connections, locating debris and partial blockages, and assessing tuberculation and internal corrosion of metallic pipes. In addition, it can be used for visually inspecting pipe walls and inner linings, examining the condition of valves and screening for obstacles or laterals before floating a free-swimming inspection tool like SmartBall®.

Other leakage detection tools

Some civic agencies in India like the Kerala Water Authority (KWA) have made use of advanced technologies such as the SmartBall® and Sahara® systems. However, these technologies have proven to be effective only while inspecting leakages in large pipelines. To effectively strengthen anti-theft measures and reduce the quantum of non-revenue water, utilities require in-depth knowledge of valves and leakages in smaller pipelines of their service networks. To this end, they have to rely on more conventional solutions for leakage detection. For instance, KWA is planning to deploy helium gas-based technology in its smaller water supply pipelines.

Helium gas-based leak detection

Several service providers in the country, such as the Municipal Corporation of Greater Mumbai (MCGM) in Maharashtra and Bangalore Water Supply and Sewerage Board (BWSSB) in Karnataka, have already deployed helium gas-based technology for water leakage detection.

This technique relies on the physical properties of helium gas to detect pipeline leakages. The gas is chemically inactive, non-toxic and does not react with water. It is present in the atmosphere in very low amounts. Tapping into these properties, civic agencies inject helium into live supply pipelines. In case any leakage point exists in the pipeline network, the gas escapes through the pipeline and finds its way to the ground surface. Civic agencies can thus check for high levels of helium above the pipelines to locate such leakages.

Civic agencies can deploy this technology without shutting down their pipeline services. In addition, it is flexible in the sense that it can be deployed to detect leakages in pipelines of any size and material. Economically, using helium gas for detecting pipeline leakages is much cheaper than other advanced detection technologies.

Sound-based leakage detection

Some civic agencies such as the Vadodara Municipal Corporation in Gujarat and MCGM are also experimenting with sound-based leak detection technology, wherein a sound unit including an amplifier is placed on the road above the supply pipelines. The sound unit is equipped to mute all background noise and only capture the sound of water flow in the pipeline. The sound can also be amplified for technicians to assess whether the water flow is smooth or there is a leakage problem.

Supporting systems

To increase the uptake of leakage detection technologies, municipal corporations have adopted several supporting systems and equipment solutions. For instance, supervisory control and data acquisition (SCADA) systems are widely used by civic agencies for collecting real-time data and monitoring water flows. The data collected through SCADA can help estimate the water losses due to undetectable small leaks in pipelines. It also helps in recording and analysing sudden changes in flow rates, which can point towards pipeline bursts and leakages. Apart from this, the civic agencies deploy geographic information system (GIS) to map their water supply and sewerage infrastructure.

Based on systems such as SCADA and GIS, utilities can also undertake hydraulic modelling of their pipeline networks. For instance, the Indore Municipal Corporation in Madhya Pradesh is planning to install SCADA and hydraulic modelling systems to detect leakages in its feeder and distribution lines. Hydraulic models provide utilities with operational support, system forecasts and automated simulations for the operations and control of water supply and sewerage systems. Utilities can also undertake water audits through such models to locate, identify and characterise the major sources of leakage.

In addition, service providers can develop command centres for monitoring and managing the city’s water supply networks. For instance, BWSSB, in collaboration with IBM, has developed an operational data dashboard and command centre. The command centre is used by BWSSB to monitor water flows across bulk flow meters in certain regions of the city. It provides information on the amount of water supplied to different parts of the distribution system, and the level of water in reservoirs and tanks. It is also equipped with GIS to enable real-time monitoring of water flows. The data dashboard provides information on key performance indicators such as the latest flow rate, total flow in the past 24 hours and the average total flow over the past seven days. It also provides the geographical location and time of the last information update.

Conclusion

Municipal corporations in India have started undertaking technology initiatives to reduce non-revenue water and leakages. Technology solutions, both advanced and conventional, have assisted service providers in identifying leakages without physically digging up pipelines. Going forward, the full potential of these technologies can be realised if the civic agencies possess the required skilled manpower to deploy them on a regular basis.

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