In Indian cities, millions of people drink contaminated water . A staggering 70% of all drinking water in India is said to be contaminated. Among 122 countries, India is the third worst on the water-quality index . In a city like Mumbai, the water reservoir is clean, but the water gets contaminated during distribution.
Water supply to city dwellers is treated at various levels and then distributed through the system. Municipality service agents collect the water samples at multiple stages and send them to laboratories periodically. However, water contamination from sources in the supply system like leakage in pipelines and storage tanks, backflow from the end-user, contamination due to intermittent supply and malfunctioning of filter plant goes untraced into end branches of the distribution network. We propose a sensor network solution for detection and mitigation of such kind of contamination towards end branches of the distribution network.
How does it work?
Our system has wireless installable units, the sensor modules, which fit along different sections of the water supply system. An inbuilt GPRS module enables connection to the cloud over the internet. The equipment is battery powered, which can be automatically charged by solar power or AC supply. Data acquired from the sensor module are compared with W.H.O set standards. Sensor modules are cloud-connected, and thus any anomaly detected is notified to the municipality personnel and the end user via an app. If the anomaly parameter exceeds the threshold value, the supply inlet valve is being turned off automatically in case of end branches of the water supply system.
The sensor module can measure turbidity, pH, TDS, pressure. More parameters, like the presence of chemical contaminants, e-Coli, and microplastics, could also be detected by adding appropriate sensors. The modules, fitted at various nodes in the water distribution system beginning at the outlet of the treatment plant until the outlet at the end user, improve the coverage of water quality monitoring considerably over the existing ones. This system helps in conducting a preliminary test of water quality.
How would it be produced?
With low-cost components and fabrication methods, it can be manufactured inexpensively and deployed to the last water connection. Moreover, this system can be used to feed-back data to an existing system to enhance its performance. The electronics of the sensor module is manufactured on a single PCB, which is encapsulated in a casing fabricated from readily available parts from hardware stores. This casing is sealed with epoxy for waterproofing. The module is easily fitted in any pipes or at the outlets with appropriate adapters. The module has mains AC supply and secondary source battery. Such an arrangement needs minimum maintenance. The module primarily consists of:
Microcontroller, GPRS UART module, pressure, pH, turbidity, sensor, and their drivers, power converter, solenoid valve, and its driver, Li-ion battery and battery charger unit.
When the system is implemented, the spread of waterborne diseases and contamination due to leakages can be avoided. Such a sensor network will help to improve the water quality and follow the prescribed standards. The proposed system can also be deployed at the end user level or community level making it more applicable than a centralized control system currently utilized by governments. Such implementation will affect millions around the globe as it can reach individual households, apartments, housing societies, municipal governments or industries.
In summary, the network of sensor modules monitors the water quality throughout the water distribution system from the outlet of the water treatment facility until the end user which helps in ensuring that the water remains potable for the city dwellers throughout its supply chain.
1. 10 crore people drinking contaminated water in India, The Economic Times, PTI, Dec 21, 2017 (https://economictimes.indiatimes.com/news/politics-and-nation/10-crore-people-drinking-contaminated-water-in-india/articleshow/62191841.cms)