To what extent the lockdown has impacted the water quality of river Yamuna (expressed in terms of CCMEWQI) in the region Delhi, India over the time period December, 2019 to July, 2020 determined by physicochemical analysis of water parameters – pH, turbidity and BOD?

Rivers has always been the major source of water supply for both industrial and domestic purposes. Thus, it is an imperative part of the environment protection program of any nation or locality to ensure that the water resources are well managed and especially the ones which are suppliers of fresh water for drinking purposes. This action involves a delicate study to understand what sort of anthropogenic activities may cause water pollution and alter the existing standards to change its suitability for human use. ‘River Quality Monitor Programs – RQMP” are developed in many nations across the globe to ensure the quality of water resources as per local and global standards. River Yamuna is a major river flowing through the National Capital Region or mainly Delhi in India, Asia. This region being the national capital has witnessed immense increase in population and industrial activities over the time. These daily activities result into the addition of various pollutants from both point and non-point sources into the river. Yamuna Action Plan-I and Yamuna Action Plan-II has been designed by the Government of India to treat this water source. The impact of this plan was not found to be that effective as the increasing human demands and human activities kept on adding organic wastes, excretory faceces, industrial effluents deteriorating the water quality. Recently, during the nation-wide lockdown because of the global pandemic has brought a temporary ban on various such activities and has to some extent contributed towards the development of the water quality of River Yamuna. As reported in various newspapers and magazines, the rivers appear to be cleaner and less polluted during the lockdown in comparison to before.

In an interview with a national news channel Dr. Rajeev Chauhan, an eminent officer of the Yamuna Action plan for over a decade reports that - "I have been associated with the Yamuna Action Plan since the year 2000 and I have never seen the river this clean. The level of pollution reduces further and its water becomes clearer near Etawah; here the water from Chambal river further dilutes the pollution. I am amazed at the effect the lockdown has had on all rivers"

This brought me to realize that this Lockdown has definitely made an impact on the water quality level of River Yamuna and thus I decided to integrate it and arrived at the research question-

(Enough details to describe the context and reason to select this RQ has already been described in the environmental context. Adding the same thing here is repetition.)

The environmental issue addressed in this investigation is about the effect of the human activity or precisely a national decision curbing the daily human activities which is the nation-wide Lockdown on the water quality of River Yamuna. To connect with this RQ has been chosen with the Lockdown and water quality index as the independent and dependent variable. The water quality index is the dependent variable in this investigation. It will be measured as the CCME WQI index (Canadian Council of Ministers of the Environmental control Water Quality Index 1.0). The detail of the calculation of this method is stated below. This variable has been chosen as this is a globally accepted standard.

 \(\text{CCME WQI} =\frac{\sum\limits^{i=n}_{i=1}(\frac{mod (Observed \ value-Ideal\ value)}{Ideal\ value}\times100)}{Number \ of\ parameters\ chosen(n) }\)

Here n indicates the number of parameters chosen to deduce the water quality. This investigation will study the water quality based on four parameters- pH, BOD and turbidity. Thus, the value of n is 3. The ideal values are taken from the latest regulations as published by Bureau of Indian Standards, New Delhi, India. The ideal or acceptable limits of these parameters also depends on the purpose for which the water is used. The ideal values for the category of water used for drinking purposes with/ without treatment has been used here. This is done because River Yamuna is a major source for drinking water in the area of study.

pH – It is a measure of the acidity of the water sample. A pH value of 7.00 is considered to be neutral while below 7.00, it is acidic and above 7.00, it is alkaline.

Turbidity- This is an optical property. It is caused due to presence of organic matter and suspended solids in water bodies.

BOD- Biological oxygen demand is a measure of the amount of oxygen that the microorganisms need to respire and degrade the organic substances in water.

The independent variable is the nation-wide Lockdown because of the COVID-19 Pandemic. This action of Government has brought a temporary restriction to various human activities hat leads to addition of phytochemicals to water bodies and pollute it. Moreover, the data will be collected for the time period from December, 2019 to July, 2020. This is because the Lockdown in India has been implemented from March 28, 2020. Thus, to have a fair and comprehensive comparison data for a period of 6 months from December 2019 to May 2019 will be used so that a wide period both before and after lockdown is included.

Approximately, River Yamuna covers an area of 50 km within the geographical map of the National Capital Region. The stream marks its course in the region from ‘Village Palla’ to ‘Jaitpur’. Three locations have been chosen in this entire course to conduct the study. The locations and the justification behind the choice has been described below:

• Location-A: ‘Palla’ – This sample site is the entry point of the river. Studies from this sample site will enable us to compare that how this particular geographical region as chosen in this investigation has been important.
• Location-B: ‘Okhla’ – This region has a wastewater treatment plant. Effluents and waste products from this particular plan are transferred to the water in this region.
• Location-C: ‘Agra Canal’- This is a source from where ‘drinking water for the city with a population of 13 million’ is supplied.

A geographical monitoring of the location – (‘Palla’ – 23 km upstream, Okhla – 29 kn downstream and ‘Agra Canal’ – 39 km downstream) reveal that the locations are chosen in a way so that they are at various distances from the entry point of the river in this region. This will enable is to have a temporal as well as a spatial variation of the water quality index.

The independent variable is the nation-wide Lockdown because of the COVID-19 Pandemic. The data will be collected for the time period from December, 2019 to July, 2020.

The investigation is based on secondary data. The data has been obtained for the values of the four parameters – pH, turbidity and BOD  for every week over the months of December, 2019 to May, 2020. The data has been procured from the website hosted by Central Pollution Control Board and administered by the Ministry of Environment and Forests, Government of India. This source is definitely credible as it is monitored from the Government’s end.

• Collecting the data of the parameters from the secondary source as mentioned.
• Calculating the water quality index using the formulas.
• Analyzing the changes using graphs.
• Deducing a conclusion about the impact of Lockdown on water quality
• Suggesting a solution to the environmental issue.

The water quality index is the dependent variable in this investigation. It will be measured as the CCME WQI index (Canadian Council of Ministers of the Environmental control Water Quality Index 1.0). The detail of the calculation of this method is stated below. This variable has been chosen as this is a globally accepted standard.

\( \text{CCME WQI }= \frac{\sum\limits^{i=n}_{i=1}(\frac{mod (Observed \ value-Ideal\ value)}{Ideal\ value}\times100)}{Number \ of\ parameters\ chosen(n) }\)

The data used here are secondary data. A brief description of the protocol followed to collect the data has been described below:

The measurement of all the variables were taken five times per month as mentioned in the website. These five values (to reduce random errors) are presented here in the table as trial values and the monthly average has been calculated.

Estimation of Water Quality Index for Location A for Dec, 2019

Water Quality Index (WQI) =

\(\frac{∑〖(|Ideal \,pH-Observed\, pH|)/(Ideal \,pH)+(|Ideal\, Turbidity-Observed \,Turbidity|)/(Idea;\,Turbidity)+(|Ideal\, BOD-Observed \,BOD|)/(Ideal \,BOD)〗}{3}\)

\(=\frac{\frac{|7-6.12|}{7}+\frac{|4.76-5.09|}{4.76}+\frac{|1.80-2.32|}{1.80}}{3}×100%\)

\(=\frac{0.131+0.071+0.292}{3}\) = 0.165 ×100 % WQI = 16.5%

The graph shows the variation of pH with time for location A, B and C. The pH of water sample taken from location A shows variation in pH from 6.12 to 6.85 between Dec,19 to May,20. The pH of water sample taken from location B shows variation in pH from 6.01 to 6.82 between Dec,19 to May,20 while the pH of water sample taken from location C shows variation in pH from 5.92 to 6.8 between Dec,19 to May,20. The water sample taken from location B is more acidic than location A whereas water sample taken from location C is more acidic than water sample taken from location B. The pH of the water sample taken from location A, B and C first decreases from Dec,19 to Feb,20 and then increases from March,20 to May,20 indicating that the variation of pH before and after lockdown respectively.

The graph shows the variation of turbidity with time for location A, B and C. The turbidity of water sample taken from location A shows variation from 5.09 ± 0.01NTU to 3.18 ± 0.01NTU between Dec,19 to May,20. The turbidity of water sample taken from location B shows variation from 5.20 ± 0.01NTU to 3.49 ± 0.01NTU between Dec,19 to May,20 while the turbidity of water sample taken from location C shows variation from 5.41 ± 0.01NTU to 3.74 ± 0.01NTU between Dec,19 to May,20.

The water sample taken from location B is more turbid than location A whereas water sample taken from location C is more turbid than water sample taken from location B. The water sample taken from the location A, B and C first decreases from Dec,19 to Feb,20 and then further decreases from March,20 to May,20 indicating that the variation of pH before and after lockdown respectively.