Water Quality IndexBeta

About Water Quality Index (WQI)

Rejuvenation of rivers and lakes calls for changing people's attitudes toward a common pool resource such as water by creating awareness, understanding the real cost of pollution and its lasting effect. At the foundation of all this is making more granular and reliable data accessible to all to ensure transparency.

ABOUT WQI WEBSITE

The Water Quality Index (WQI) website—an initiative of the Tata Centre for Development (TCD) at the University of Chicago—brings together multiple data sets on surface water quality, draws insights from them and presents a holistic picture of India’s water quality through different features that are easy to understand. The insights presented on the website will help policy makers make informed decisions about use of water and how to keep India’s waterways healthy.

WQI not only synthesizes multiple datasets—real-time and historical—but also integrates them in a user-friendly tool. The dynamic map is useful in pinpointing the exact location of water quality monitoring stations and identifying pollution sources for effective intervention.

FEATURES

a. Water Quality Index: WQI brings together surface water quality data from multiple sources, including government and academic research databases, to create a single indicator of health of a water body. This single index can be used to compare the health of water bodies across India and also across different days.

b. Applications of water: The website shows users whether water quality in a particular stretch of a water body is fit for any of the three applications: drinking, bathing and industrial uses.

c. Parameters: Six crucial parameters of a particular monitoring station or a stretch of water body are rated ‘safe’ and ‘unsafe’ to help users identify biological and chemical characteristics of river water. Historical trends of all the six parameters are also available.

METHODOLOGY

Real-time river water quality data is collected by using mobile sensors. Attached to a boat that goes on a predefined route, the sensors are immersed in water and a handheld meter records the data. The time-stamped and geo-tagged data is then downloaded from sensors, cleaned, and made available in CSV files. Point samples from the rivers are also collected and sent to a laboratory. All the parameter readings are verified to match sensor readings. The data from the Central Pollution Control Board (CPCB) used in the website is an average of all the data the agency has collected each year. Sampling frequency is unknown.

a. Water Quality Index: We have used the CPCB’s methodology, wherein each of the parameters—Dissolved Oxygen (DO), Faecal Coliform (FC), pH and Biological Oxygen Demand (BOD)—has been assigned a weight according to their relative importance in the overall quality of surface water. Maximum weight is assigned to DO and FC due to their major importance in water quality assessment. pH and BOD are given less weight.

b. Applications of water: This is a modified version of the methodology accepted by the National Sanitation Foundation (NSF), the USA, and is widely used in many countries. The modification is done in terms of weight given to all the four parameters for computation of WQI.

To gauge whether the surface water quality is fit for drinking and bathing, the safe limits of DO, TC, pH and BOD are referred. It is to be noted that to assess suitability for drinking, we follow the standards set for drinking water that can be had without conventional treatment, but after disinfection. To gauge surface water’s applicability for industrial uses, we refer to the safe limits of pH and Electrical Conductivity.

c. Parameters: As every boat ride follows the upstream-downstream-upstream trajectory for around four hours, it is most reasonable to plot the temporal median value of mobile sensor data. Since the CPCB annual dataset has only one average value for each parameter in a specific location, median can’t be calculated. Hence, that same value is used to gauge whether a parameter is within or beyond the safe limit.

DATA SOURCES

Historical data: We have used the Central Pollution Control Board’s annual data for the year 2013, 2014, 2015 and 2016 available on ENVIS Centre on Control of Pollution Water, Air and Noise.

Real-time data: One of our research projects, Water-to-Cloud, is about monitoring surface water quality in real time with the help of mobile sensors to empower researchers and policymakers with high-frequency spatial and temporal data. This methodology enables collection of water quality data at different times of the day, and at different locations across large water bodies.

DISCLAIMER

On Water Bodies: The website shows the water quality index of the rivers and their tributaries for which CPCB has data on all parameters needed for calculating WQI.

On Data: The website has used publicly available annual CPCB data on water bodies for the year 2013, 2014, 2015 and 2016. For some stretches of River Ganga, Yamuna and Godavari—where TCD has been collecting real-time data since July 2017—the latest data is available.

The CPCB data that the website has used is an annual average of observed values of each parameter from 1128 monitoring stations. However, since data on crucial parameters such as DO, pH, BOD, Total Coliform and Faecal Coliform are not available for some stations, this website does not show water quality index for some monitoring stations.

On Location: Real-time data, which comes with geographical coordinates, are accurately plotted on the maps. However, since exact geographical coordinates of monitoring sites are missing in the publicly available CPCB data on surface water quality of rivers and their tributaries, approximate locations are plotted on the maps. The geo-coordinates have been identified by searching for the location names as given in the CPCB raw data files.

On Date: As exact dates of collection of CPCB data are not available, two dates, October 1 and April 1, are used to plot the data. These two dates have been taken because of the separation of two quarters between them, which makes the visualisation reader-friendly.

To know more about the website and the project, write to tcd@uchicago.edu.

Produced with support from

About TCD

The Tata Centre for Development (TCD) at the University of Chicago works to identify novel solutions to India’s most pressing development challenges and to ensure that these ideas are translated into outcomes that improve people’s lives. Launched in 2016 with generous support from the Tata Trusts, TCD follows a unique approach that harnesses evidence-based insights from UChicago’s rigorous economics research.

An affiliated center of the Becker Friedman Institute for Economics at UChicago, TCD upholds the university’s tradition of applying economic thinking to a wide range of social challenges and advancing important research on India through a convergence of scholars from across disciplines.

To translate research insights into policy action, TCD engages with policymakers at all levels of government and policy entrepreneurs across sectors and launches pilot projects to demonstrate success. Representing the joint work of the Tata Trusts and the University of Chicago, TCD asks difficult questions, challenges conventional thinking, and creates a new model for impact in India.

TCD targets research projects that will contribute new, evidence-based solutions to difficult policy and development problems in India and whose insights can affect change in the real world. Whenever possible, TCD projects are designed and implemented in collaboration with government partners and policy entrepreneurs so that research findings generate impact in real time.

Water bodies in India bear the brunt of booming population and rapidly expanding urban areas

Water pollution and inadequate sanitation facilities cost India INR 470-610 Billion each year

India has set an ambitious target of cleaning its rivers by 2030

The country has 183, 530 km of waterways, but just one monitoring station every 88 km.

Is it enough to monitor the health of our waterways—a lifeline to more than a billion people?

Waterways are complex and dynamic systems; to improve their water quality, we must first have granular and reliable data.

Monitoring
Sampling
Frequency
Coverage
Presentation
Storage

Monitoring

What We Have

Monitoring done either by random grab sampling or installing sensors in a specific location

What We Need

Dynamic monitoring by taking real-time sensors through the course of a water body and collecting voluminous data

Sampling

What We Have

Single-point measurements which do not give reliable and representative data

What We Need

Multiple measurements to bring granularity and shape effective interventions

Frequency

What We Have

Low frequency data collection which limits the possibility of making timely intervention

What We Need

High-resolution temporal data to help evaluate micro trends

Coverage

What We Have

Limited number of samples from large stretches of water which fails to present a holistic picture

What We Need

High-resolution spatial data to help assess local pollution trends and identify hotspots

Presentation

What We Have

Data in tabular forms with values of different parameters, lacking comprehensiveness

What We Need

Data visualizations like color-coded heat maps for easy understanding

Storage

What We Have

Data from monitoring agencies which are stored in disparate sources that have restricted access

What We Need

Single open access platform for full data disclosure, transparency and accessibility

Waterways are complex and dynamic systems; to improve our rivers, we must first improve our data.

	What We Have	What We Need
Monitoring	Monitoring done either by random grab sampling or installing sensors in a specific location	Dynamic monitoring by taking real-time sensors through the course of a water body and collecting voluminous data
Sampling	Single-point measurements which do not give reliable and representative data	Multiple measurements to bring granularity and shape effective interventions
Frequency	Low frequency data collection which limits the possibility of making timely intervention	High-resolution temporal data to help evaluate micro trends
Coverage	Limited number of samples from large stretches of water which fails to present a holistic picture	High-resolution spatial data to help assess local pollution trends and identify hotspots
Presentation	Data in tabular forms with values of different parameters, lacking comprehensiveness	Data visualizations like color-coded heat maps for easy understanding
Storage	Data from monitoring agencies which are stored in disparate sources that have restricted access	Single open access platform for full data disclosure, transparency and accessibility

See for yourself how clean or polluted the stretches of the water bodies are, follow the historical trends, and spot the possible hotspots

What can we learn from the data we have already?

We can explore overall health of a water body, its quality based on crucial parameters and it’s suitability for different applications. Select a water body, state, and location to explore detailed information.

Data Set

State

Water Body

Location

Explore