It can help you. http://www.water-research.net/index.php/water-treatment/water-monitoring/monitoring-the-quality-of-surfacewaters This is online water quality index calculator.

Dear Sunil  Kumar Srivastava

There are several publication regarding this issue and the literature is growing nowadays exponentialy

You can search here on Rg or elsewhere e.g Scholar google for reserach items or articles or even monographs. I suggest to you to read  first time publication  with overview characters and after some certain articles dealing with indivdual methods

with kind regards

Zsolt Nagy László

Between our publications you can find some articles dealing with this issue or make a review of Borics Gábor articles etc etc

Hope I could help you in some manner

thank you sir

Please refer : 

CR Ramakrishnaiah and others 2009. Assessment of water quality Index ........E Journal of Chemistry, 6 (2), 

paper and related references on line available

Dear Dr. Sunil Kumar Srivastava,

I am explaining the WQI in a simple way for easy understanding.

WQI: It may be defined as a rating, reflecting the composite influence of different water quality parameters on the overall quality of water. The main objective of computing of water quality index (WQI) is to turn the complex water quality data into information which is easily understandable and usable.

Selection of  parameters: First, study the Indian Standard (BIS 2004) for drinking water specification. Here,  the physicochemical parameters along with the desirable limits and related health effects are given. A parameter has to be selected based on its impact in the overall quality of water and heath effects. This standard is freely available in net. However, I am enclosing the same for your convenience (see below).

Computation of WQI: The WQI is computed following the three steps.

First step – Assigning of weight (wi) to the selected water parameters (e.g., pH, TDS, TH, HCO3, Cl, SO4, NO3, Fe,  ……) according to their relative importance in the overall quality of water for drinking purposes (weight may be from 1 to 5).

Second step – Computation of a relative weight (Wi) of the chemical parameter using the following equation:                                                                                

Wi = wi / ∑  wi ( i = 1 to n) 

where, Wi is the relative weight, wi is the weight of each parameter and 'n' is the number of parameters

Third step - Assigning of a quality rating scale (qi) for each parameter, as below:

qi = (Ci / Si ) x 100                                                                                       

where,  qi is the quality rating, Ci is the concentration of each chemical parameter in each water sample in mg/l, and Si is the guide line value/desirable limit as given in Indian drinking water standard (BIS 2004).

For computation of  WQI, the sub index (SI) is first determined for each chemical parameter, as given below:                                                                            

SIi = Wi x qi     

WQI = ∑ SIi 1 - n                                            

where, SIi is the subindex of ith parameter; Wi is relative weight of ith parameter; qi is the rating based on concentration of ith parameter and 'n' is the number of chemical parameters.

Classification of water :The water may be classified into five types based on computed WQI as given below:

WQI range and water type:

< 50             

Excellent water;

50 - 100            

Good water;

100- 200           

Poor water;

200 – 300          

Very poor water;

> 300                

Water unsuitable for drinking.

For more details, you can consult my paper published in 'Water Environment Research (USA)'. The link is given below:

https://www.researchgate.net/publication/280062602_Hydrogeochemistry_and_Water_Quality_Index_in_the_Assessment_of_Groundwater_Quality_for_Drinking_Uses

Give your feedback. With good wishes - Dr. Asit

Article Hydrogeochemistry and Water Quality Index in the Assessment ...

I agree with the explanation of Asit Kuman.....

Very clear and scholarly explanation by Dr. Asit Kumar. Thank you for the same.

Dr. N B Narasimha Prasad,

Thanks for your recognition. I also appreciate you for addressing and providing valuable comments on the questions related to water and environment. Regards  

For calculating water quality index, you have to select a number of important parameter datasets available from Pollution control Board. Then you have to find the acceptable range & find the level of pollution of the selected parameters. After that you assign weightage to each of the parameters,  SI of the highest value will be the WQI.

Dear Sunil  Kumar Srivastava

I recommend searching the following site

http://portalpnqa.ana.gov.br/indicadores-indice-aguas.aspx

Attached are various technical reports, user manuals and WQI calculators made available through the Canadian Council of Ministers of the Environment (CCME) web site.  They are a good place to start if you are developing your own index for both soil and water.

You may also like to see this approach. hope you find this interesting

Article Comparative evaluation of water quality zonation within Dwar...

Thanks to all of you for valuable suggestion

I do not know the correct equation to calculate WQI.

How this can be done. Please respond.

Dr. Rejomon,

I have described the methodology for computation of WQI (The method which I have followed). You can also read the following paper: Article Hydrogeochemistry and Water Quality Index in the Assessment ...

Regards

Dear Sunil,

Please also have a look at these useful links.

http://shodhganga.inflibnet.ac.in/bitstream/10603/8242/10/10_chapter%204.pdf

http://shodhganga.inflibnet.ac.in/bitstream/10603/10079/12/12_chapter%207.pdf

http://www.moef.nic.in/sites/default/files/nlcp/B%20-%20Water%20Quality/B-30.pdf

http://www.m-hikari.com/es/es2015/es1-2015/boahES1-4-2015.pdf

Good luck!

Dear Dr. Asit Kumar Batabyal,

How you can assign a weightage 1, 2, 3, ... 5 to water quality parameters to calculate relative weight.

Please respond.

Dr. Rejomon George

Dr. Rejomon George,

I have already mentioned in the description: Assigning of weight (wi) to the selected water parameters (e.g., pH, TDS, TH, HCO3, Cl, SO4, NO3, Fe,  ……) according to their relative importance in the overall quality of water for drinking purposes (weight may be from 1 to 5).

Regards

The following link may be useful to you:

http://www.moef.nic.in/sites/default/files/nlcp/B%20-%20Water%20Quality/B-30.pdf

Interesting question

I agree with the explanation of Dr. Asit Kumar Batabyal .

The paper posted by Asit Kumar Batabyal explains WQI equation calculation clearly. Although, you can find Online tool for WQI calculation from the below link

https://www.water-research.net/index.php/water-treatment/water-monitoring/monitoring-the-quality-of-surfacewaters

Thank you for all the answers.

But my challenge of assigning weights to the chemical parameters, does the weights assignment take consideration of the underlying geology?

How the geological conditions in an area affects with the water quality?

Dr. Rejomon - Please see the following links:

The influence of geology and other environmental factors on stream water chemistry and benthic invertebrate assemblages

https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=2340&context=etd

How can the geology of a watershed impact the water quality?

https://www.researchgate.net/post/How_can_the_geology_of_a_watershed_impact_the_water_quality

What controls natural water quality?

https://www.americangeosciences.org/critical-issues/faq/what-controls-natural-water-quality

What Factors Affect Water Quality?

http://oregonexplorer.info/content/what-factors-affect-water-quality

Regards

Sir, still I am confused about the weight of parameters.@ Asit Kumar Batabyal

Babita Bakhara - Read the answer (given a year back) and also the attached paper. Then, you may ask. Best wishes

Are you still interested in how to calculate it?

Hello Guy, The Canadian Council of Environment Ministers (CCME) has released the Water Quality Index 2.0

More details on the app can be found on the CCME website at http://www.ccme.ca/en/resources/canadian_environmental_quality_guidelines/calculators.html

📷

Hello Sunil Kumar Srivastava ,

When I scrubbed through the net regarding your question, I found that there are several Water quality indexes and to name a few:

• National Sanitation Foundation Water Quality Index (NSFWQI)
• Canadian Council of Ministers of Environment Water Quality Index (CCMEWQI)
• Oregon Water Quality Index (OWQI)

and several others. Each has their own merits and demerits. The methodology that Asit Kumar Batabyal explained is NSFWQI. Compared to the scale of classification types he stated at the end, there exists an even finer scale.

Reference :

Tyagi, S., Sharma, B., Singh, P. and Dobhal, R., 2013. Water quality assessment in terms of water quality index. American Journal of Water Resources, 1(3), pp.34-38.

Dear Dr. Asit Kumar Batabyal

kindly , I need your opinion pleas ;

can I use the Canadian WQI in assessment of treated refinery waste water for irrigation .

Best wishes

Dr. Afaf Jadaan Obeid - You can try.

Read the following papers. Useful to understand the problem.

Evaluation of Shiraz wastewater treatment plant effluent quality for agricultural irrigation by Canadian Water Quality Index (CWQI)

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3627627/

Evaluation of Wastewater from a Refinery Treatment Plant for Agricultural Use

https://www.researchgate.net/publication/248703481_Evaluation_of_Wastewater_from_a_Refinery_Treatment_Plant_for_Agricultural_Use

Quality assessment of treated wastewater to be reused in agriculture

https://www.gjesm.net/article_30399_01d3772e24a59a4fbed6caac0b96541f.pdf

Wastewater Reuse in Agriculture

https://www.mdpi.com/2071-1050/9/10/1734/pdf

Regards

Dr. Asit Kumar Batabyal

Then, the wi weights will depend on the relative importance granted by the author of the paper? (according to the importance of the health of the people and the vulnerability of the place)

We are currently undertaking the determination of a ten year, multi site (350+) WQI specifically for Placer mining and the downstream effect on the aqautic enviroment weighing specific physical parameters like TSS and settleability with greater importance than most other physical parameters.

Marion Pastene - Yes, the weight (wi) of a water parameter is considered based on the relative importance of that parameter in the overall quality of water for drinking purposes.

This document has a clear explanation on how to calculate the Water Quality Index (WQI).

Article Groundwater Quality Assessment Using Water Quality Index and...

https://doi.org/10.1016/j.jafrearsci.2018.06.034

This article explains clearly how the Water Quality Index (WQI) can be calculated.

Good question, by the way is there any WQI for seawater other than the Canadian one?

Anyone using the ICA index?, How can I calculate it if I use microbiological parameters in CFU/100mL?

Hi,

A water quality indices provide a convenient means of summarizing complex water quality data which can easily understand by general audience. There are several water quality indices have developed for different purposes. However, to determine the pollution levels for drinking purposes, I recommend to calculate CCME WQI (Canadian Council of Ministers of the Environment WQI) since its easy to handle and reliable to adjust the requirements (Water Quality Standards) according to the country or region. Further, it facilitates to determine the quality of different categories such as, water quality for drinking, aquatic animals and livestock.

The CCME Water Quality Index is based on a formula developed by the British Columbia Ministry of Environment, Lands and Parks and modified by Alberta Environment.

Following links will help you to calculate WQI,

Article Water Quality Index (CCME-WQI) Based Assessment Study of Wat...

Article ASSESSMENT OF WATER QUALITY INDEX FOR GROUNDWATER IN THE KEL...

http://ceqg-rcqe.ccme.ca/download/en/138

Since we installed automatic stations for measure water quality, I started to use the CCME index, and for this application the CCME index was the most practical

How to calculate WQI if i want to add microbial parameter in that because for Coliforms its given permissible limit is '0'?

Assessment of Hydrochemical Water Quality on Al Delmaj Marsh Application Of The CCME WQI

I am interested

I am interested

You can use the calculator from the site of Water Research Center:

https://water-research.net/index.php/water-treatment/water-monitoring/monitoring-the-quality-of-surfacewaters

Dear Sunil,

This publication will help you to calculate the water quality index which is unbiased and easy method. Please go through this publication and let me know for any help.

https://www.researchgate.net/publication/331009233_Development_of_new_integrated_water_quality_index_IWQI_model_to_evaluate_the_drinking_suitability_of_water

Water Quality Index Calculator - Water Research Center

https://www.water-research.net › watrqualindex

Calculating NSF Water Quality Index (WQI).

Article Groundwater Quality Assessment Using Water Quality Index and...

This publication will help you

Article Prediction of water quality index using artificial neural ne...

Article Prediction of water quality index using artificial neural ne...

Water Quality Index Calculator - Water Research Center

https://www.water-research.net › watrqualindex

Calculate the water quality index of a surface water

WQI

You can use NDWI index

In the first step each of the 10 parameters (TDS, pH, Ca2+, Mg2+, Na+, HCO3-, K+, Cl-, SO42-, NO3-) has been assigned a weight (wi) according to its relative importance in the overall quality of water intended for drinking purposes. The maximum weight of 5 is given to: TDS and NO3-.

In second step, the relative weight (Wi) was determined by the following equation:

📷 (2)

Where: “Wi” is the relative weight; “wi” is the weight of each individual parameter and “n” is the number of parameters. In the third step, a quality rating scale (qi) is calculated from the different parameters using the following equation:

📷

(3)

Where qi is the quality rating, Ci is the concentration of each selected parameter from water sample in mg/L, and Si is the WHO Standard of drinking water for each selected parameter in mg/L, according to the guidelines of WHO for computing the WQI. In the final stage of WQI, SI was determined for each water quality parameter by multiplying relative weight (Wi) with quality rating scale (qi). The sum of SI is equivalent to the water quality index.

📷(4)

📷(5)

The computed WQI were classified as follows: Excellent, (WQI < 50); Good, (WQI, 50-10 0); Poor, (100-200); Very Poor, (200-300) and >300 unsuitable for drinking water.

A water quality index (WQI) is an index by which water quality data is summarized and from which we know about the quality of drinking water from any water source. Water quality indices use a methodology to convert a set of data into a single value to express the quality of water. Physical (temperature, pH and transparency) and chemical (BOD, DO, total Phosphorus, total ammonia, Calcium, Magnesium, Sodium, Potassium, bicarbonate, nitrate and phosphate) contents of water are taken into consideration. The Weighted Arithmetic index of Brown et al. (1972) is used for the calculation of the water quality of a water body. Hence WQI is a very effective method for determining the quality of water.

Article Hydrogeochemical signatures and suitability assessment of gr...

You can go through the attached paper for more details about WQI and its calculation procedure.

Conference Paper EVALUATION OF DRINKING WATER QUALITY IN TERMS OF WATER QUALI...

Dear Sunil

I find that the explanations given by Dr. Bouteldjaoui and Dr. Asit Kumar Batabyal excellent. I do not add more so as not to flood you with similar information. Professor emeritus Ahmed KETTAB

i suggested, you should follow the book entitled "water quality indices" written by Abbasi & Abbasi 2012 publisher Elsevier.

Please go through the methodology section of this research article " Hydrogeochemical signatures and suitability assessment of groundwater with elevated fluoride in unconfined aquifers Badin district, Sindh, Pakistan"

Article Hydrogeochemical signatures and suitability assessment of gr...

Dear Bouteldjaoui

your explanations are very correct and interesting.

The National Sanitation Foundation (NSF) Water Quality Index (wQI) was one of the analytical tools used to summarize the data. Essentially, the WQI converts the concentration data for nine analytes into one offive water quality classes, ranging from ·very bad" to· excellent".

https://water-research.net/index.php/water-treatment/water-monitoring/monitoring-the-quality-of-surfacewaters

• 10.35940/ijitee.I1051.0789S219

Jwad K Manii

I use fuzzy logic methods.

In my opinion, the question is not a straight forward question that demands a specific answer. This is because there are several water quality indices (WQI's) that has been in use in literature for decades. These include; Weighted version of Solway Index (Solway River Purification Board, 1978), National Sanitation Foundation Water Quality Index (NSFWQI), Oregon Water Quality Index (OWQI), Canadian Council of Ministers of the Environment Water Quality Index (CCMEWQI), Recreational water quality index (RWQI), Aquatic Toxicity Index (ATI) and Water Pollution Index (WPIKR). These WQI’s are based on the comparison of the water quality parameters to regulatory standards as well as objectives such as environmental health and ecosystem vitality, human and ecosystem health, and, human use and ecological needs. These objectives aid in highlighting potential ecosystem dysfunctions thus, providing possible early warning ecological/pollution problems. Thus, depending on the aim/objectives of your project the particular WQI that best fits your objectives is adopted and used or applied. Based on your findings, the calculated WQI (single value) is used to significantly inform the underlying research needs and approaches towards either restoration or protection for the purposes of efficient and sustainable management of that particular surface water resource.

dear Sunil Kumar

you can find answer in the following link

regards

https://www.dropbox.com/s/dtw5yn960dl5w0o/Water%20quality%20tigirts%20iraq.pdf?dl=0

Alaa G Khalaf

PhD Geomatics Engineering

Specific weight (wi) is determined by estimation, or are there mathematical methods for calculating specific weight, for example, using mathematical equations?