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Recent advancements in water treatment

For immediate release, acs news service weekly presspac: january 19, 2022.

Generating clean, safe water is becoming increasingly difficult. Water sources themselves can be contaminated, but in addition, some purification methods can cause unintended harmful byproducts to form. And not all treatment processes are created equal with regard to their ability to remove impurities or pollutants. Below are some recent papers published in ACS journals that report insights into how well water treatment methods work and the quality of the resulting water. Reporters can request free access to these papers by emailing  newsroom@acs.org .

“Drivers of Disinfection Byproduct Cytotoxicity in U.S. Drinking Water: Should Other DBPs Be Considered for Regulation?” Environmental Science & Technology Dec.15, 2021

In this paper, researchers surveyed both conventional and advanced disinfection processes in the U.S., testing the quality of their drinking waters. Treatment plants with advanced removal technologies, such as activated carbon, formed fewer types and lower levels of harmful disinfection byproducts (known as DBPs) in their water. Based on the prevalence and cytotoxicity of haloacetonitriles and iodoacetic acids within some of the treated waters, the researchers recommend that these two groups be considered when forming future water quality regulations.

“Complete System to Generate Clean Water from a Contaminated Water Body by a Handmade Flower-like Light Absorber” ACS Omega Dec. 9, 2021 As a step toward a low-cost water purification technology, researchers crocheted a coated black yarn into a flower-like pattern. When the flower was placed in dirty or salty water, the water wicked up the yarn. Sunlight caused the water to evaporate, leaving the contaminants in the yarn, and a clean vapor condensed and was collected. People in rural locations could easily make this material for desalination or cleaning polluted water, the researchers say.

“Data Analytics Determines Co-occurrence of Odorants in Raw Water and Evaluates Drinking Water Treatment Removal Strategies” Environmental Science & Technology Dec. 2, 2021

Sometimes drinking water smells foul or “off,” even after treatment. In this first-of-its-kind study, researchers identified the major odorants in raw water. They also report that treatment plants using a combination of ozonation and activated carbon remove more of the odor compounds responsible for the stink compared to a conventional process. However, both methods generated some odorants not originally present in the water.

“Self-Powered Water Flow-Triggered Piezocatalytic Generation of Reactive Oxygen Species for Water Purification in Simulated Water Drainage” ACS ES&T Engineering Nov. 23, 2021

Here, researchers harvested energy from the movement of water to break down chemical contaminants. As microscopic sheets of molybdenum disulfide (MoS2) swirled inside a spiral tube filled with dirty water, the MoS2 particles generated electric charges. The charges reacted with water and created reactive oxygen species, which decomposed pollutant compounds, including benzotriazole and antibiotics. The researchers say these self-powered catalysts are a “green” energy resource for water purification.

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Articles on Water quality

Displaying 1 - 20 of 89 articles.

Gaps in reporting of nitrogen fertiliser use on farms leave an incomplete picture of impacts on water quality

Mike Joy , Te Herenga Waka — Victoria University of Wellington and Megan Cornforth-Camden , Te Herenga Waka — Victoria University of Wellington

Is hard water bad for you? 2 water quality engineers explain the potential benefits and pitfalls that come with having hard water

Sarah Blank , Iowa State University and Timothy Ellis , Iowa State University

We need faster, better ways to monitor NZ’s declining river health – using environmental DNA can help

Michael Bunce , University of Otago and Simon Jarman , Curtin University

PFAS: how research is uncovering damaging effects of ‘forever chemicals’

Eadaoin Carthy , Dublin City University and Abrar Abdelsalam , Dublin City University

There’s a hidden source of excess nutrients suffocating the Great Barrier Reef. We found it

Douglas Tait , Southern Cross University and Damien Maher , Southern Cross University

From pests to pollutants, keeping schools healthy and clean is no simple task

Janet Hurley , Texas A&M University

Freshwater quality is one of New Zealanders’ biggest concerns – water-trading ‘clubs’ could be part of the solution

Julia Talbot-Jones , Te Herenga Waka — Victoria University of Wellington and Yigit Saglam , Te Herenga Waka — Victoria University of Wellington

As climate change warms rivers, they are running out of breath – and so could the plants and animals they harbor

Li Li (李黎) , Penn State

Consumers want NZ farmers to comply with regulations – better monitoring and transparency would help to build trust

Pavel Castka , University of Canterbury ; Corey Ruha , University of Waikato ; John Reid , University of Canterbury , and Xiaoli Zhao , Lincoln University, New Zealand

Cholera: vaccines can stop the spread, but the biggest deterrent is clean water

Edina Amponsah-Dacosta , University of Cape Town and Julie Copelyn , University of Cape Town

Why shouldn’t I pour oil or paint down the sink? And what should I do instead?

Ian A. Wright , Western Sydney University

South Africa’s drinking water quality has dropped because of defective infrastructure and neglect – new report

Anja du Plessis , University of South Africa

Drinking fountains in every town won’t fix all our water issues – but it’s a healthy start

John Charles Skinner , Macquarie University ; Kylie Gwynne , Macquarie University , and Tom Calma , University of Canberra

UK waters are too polluted to swim in – but European countries offer answers

Tanja Radu , Loughborough University

Guinea worm: A nasty parasite is nearly eradicated, but the push for zero cases will require patience

Kimberly Paul , Clemson University

It’s hot, and your local river looks enticing. But is too germy for swimming?

Ian A. Wright , Western Sydney University and Nicky Morrison , Western Sydney University

Fukushima to release wastewater – an expert explains why this could be the best option

Jim Smith , University of Portsmouth

Travelling around Australia this summer? Here’s how to know if the water is safe to drink

Ian A. Wright , Western Sydney University and Jason Reynolds , Western Sydney University

Repairing gullies: the quickest way to improve Great Barrier Reef water quality

Andrew Brooks , Griffith University and James Daley , Griffith University

Countless reports show water is undrinkable in many Indigenous communities. Why has nothing changed?

Bradley J. Moggridge , University of Canberra ; Cara D. Beal , Griffith University , and Nina Lansbury , The University of Queensland

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• Climate change
• Coral reefs
• Drinking water
• Great Barrier Reef
• Great Barrier Reef Marine Park
• New Zealand
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Associate Professor in Environmental Science, Western Sydney University

Professorial Fellow, ARC Centre of Excellence for Coral Reef Studies, James Cook University

Morgan Foundation Senior Research Fellow in Freshwater Ecology and Environmental Science, Te Herenga Waka — Victoria University of Wellington

Adjunct professor, University of Auckland, Waipapa Taumata Rau

Senior Lecturer, Western Sydney University

PSM, Adjunct Senior Research Fellow, College of Science and Engineering, James Cook University

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A comprehensive review of water quality indices (WQIs): history, models, attempts and perspectives

• Review paper
• Published: 11 March 2023
• Volume 22 , pages 349–395, ( 2023 )

Cite this article

• Sandra Chidiac   ORCID: orcid.org/0000-0002-1822-119X 1 ,
• Paula El Najjar 1 , 2 ,
• Naim Ouaini 1 ,
• Youssef El Rayess 1 &
• Desiree El Azzi 1 , 3  

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Water quality index (WQI) is one of the most used tools to describe water quality. It is based on physical, chemical, and biological factors that are combined into a single value that ranges from 0 to 100 and involves 4 processes: (1) parameter selection, (2) transformation of the raw data into common scale, (3) providing weights and (4) aggregation of sub-index values. The background of WQI is presented in this review study. the stages of development, the progression of the field of study, the various WQIs, the benefits and drawbacks of each approach, and the most recent attempts at WQI studies. In order to grow and elaborate the index in several ways, WQIs should be linked to scientific breakthroughs (example: ecologically). Consequently, a sophisticated WQI that takes into account statistical methods, interactions between parameters, and scientific and technological improvement should be created in order to be used in future investigations.

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1 Introduction

Water is the vital natural resource with social and economic values for human beings (Kumar 2018 ). Without water, existence of man would be threatened (Zhang 2017 ). The most important drinking sources in the world are surface water and groundwater (Paun et al. 2016 ).

Currently, more than 1.1 billion people do not have access to clean drinking water and it is estimated that nearly two-thirds of all nations will experience water stress by the year 2025 (Kumar 2018 ).

With the extensive social and economic growth, such as human factors, climate and hydrology may lead to accumulation of pollutants in the surface water that may result in gradual change of the water source quality (Shan 2011 ).

The optimal quantity and acceptable quality of water is one of the essential needs to survive as mentioned earlier, but the maintenance of an acceptable quality of water is a challenge in the sector of water resources management (Mukate et al. 2019 ). Accordingly, the water quality of water bodies can be tested through changes in physical, chemical and biological characteristics related to anthropogenic or natural phenomena (Britto et al. 2018 ).

Therefore, water quality of any specific water body can be tested using physical, chemical and biological parameters also called variables, by collecting samples and obtaining data at specific locations (Britto et al. 2018 ; Tyagi et al. 2013 ).

To that end, the suitability of water sources for human consumption has been described in terms of Water Quality Index (WQI), which is one of the most effective ways to describe the quality of water, by reducing the bulk of information into a single value ranging between 0 and 100 (Tyagi et al. 2013 ).

Hence, the objective of the study is to review the WQI concept by listing some of the important water quality indices used worldwide for water quality assessment, listing the advantages and disadvantages of the selected indices and finally reviewing some water quality studies worldwide.

2 Water quality index

2.1 history of water quality concept.

In the last decade of the twentieth century, many organizations involved in water control, used the water quality indices for water quality assessment (Paun et al. 2016 ). In the 1960’s, the water quality indices was introduced to assess the water quality in rivers (Hamlat et al. 2017 ).

Horton ( 1965 ), initially developed a system for rating water quality through index numbers, offering a tool for water pollution abatement, since the terms “water quality” and “pollution” are related. The first step to develop an index is to select a list of 10 variables for the index’s construction, which are: sewage treatment, dissolved oxygen (DO), pH, coliforms, electroconductivity (EC), carbon chloroform extract (CCE), alkalinity, chloride, temperature and obvious pollution. The next step is to assign a scale value between zero and 100 for each variable depending on the quality or concentration. The last step, is to designate to each variable is a relative weighting factor to show their importance and influence on the quality index (the higher the assigned weight, the more impact it has on the water quality index, consequently it is more important) (Horton 1965 ).

Later on, Brown et al. ( 1970 ) established a new water quality index (WQI) with nine variables: DO, coliforms, pH, temperature, biochemical oxygen demand (BOD), total phosphate, nitrate concentrations, turbidity and solid content based on a basic arithmetic weighting using arithmetic mean to calculate the rating of each variable. These rates are then converted not temporary weights. Finally, each temporary weight is divided by the sum of all the temporary weights in order to get the final weight of each variable (Kachroud et al. 2019a ; Shah and Joshi 2017 ). In 1973, Brown et al., considered that a geometric aggregation (a way to aggregate variables, and being more sensitive when a variable exceeds the norm) is better than an arithmetic one. The National Sanitation Foundation (NSF) supported this effort (Kachroud et al. 2019a ; Shah and Joshi 2017 ).

Steinhart et al. ( 1982 ) developed a novel environmental quality index (EQI) for the Great Lakes ecosystem in North America. Nine variables were selected for this index: biological, physical, chemical and toxic. These variables were: specific conductance or electroconductivity, chloride, total phosphorus, fecal Coliforms, chlorophyll a , suspended solids, obvious pollution (aesthetic state), toxic inorganic contaminants, and toxic organic contaminants. Raw data were converted to subindex and each subindex was multiplied by a weighting factor (a value of 0.1 for chemical, physical and biological factors but 0.15 for toxic substances). The final score ranged between 0 (poor quality) and 100 (best quality) (Lumb et al. 2011a ; Tirkey et al. 2015 ).

Dinius ( 1987 ), developed a WQI based on multiplicative aggregation having a scale expressed with values as percentage, where 100% expressed a perfect water quality (Shah and Joshi 2017 ).

In the mid 90’s, a new WQI was introduced to Canada by the province of British Columbia, and used as an increasing index to evaluate water quality (Lumb et al. 2011b ; Shah and Joshi 2017 ). A while after, the Water Quality Guidelines Task Group of the Canadian Council of Ministers of the Environment (CCME) modified the original British Columbia Water Quality Index (BCWQI) and endorsed it as the CCME WQI in 2001(Bharti and Katyal 2011 ; Lumb et al. 2011b ).

In 1996, the Watershed Enhancement Program (WEPWQI) was established in Dayton Ohio, including water quality variables, flow measurements and water clarity or turbidity. Taking into consideration pesticide and Polycyclic Aromatic Hydrocarbon (PAH) contamination, is what distinguished this index from the NSFWQI (Kachroud et al. 2019a , b ).

Liou et al. (2003) established a WQI in Taiwan on the Keya River. The index employed thirteen variables: Fecal coliforms, DO, ammonia nitrogen, BOD, suspended solids, turbidity, temperature, pH, toxicity, cadmium (Cd), lead (Pb), copper (Cu) and zinc (Zn). These variables were downsized to nine based on environmental and health significance: Fecal coliforms, DO, ammonia nitrogen, BOD, suspended solids, turbidity, temperature, pH and toxicity. Each variable was converted into an actual value ranging on a scale from 0 to 100 (worst to highest). This index is based on the geometric means (an aggregation function that could eliminate the ambiguous caused from smaller weightings) of the standardized values (Akhtar et al. 2021 ; Liou et al. 2004 ; Uddin et al. 2021 ).

Said et al. ( 2004 ) implemented a new WQI using the logarithmic aggregation applied in streams waterbodies in Florida (USA), based on only 5 variables: DO, total phosphate, turbidity, fecal coliforms and specific conductance. The main idea was to decrease the number of variables and change the aggregation method using the logarithmic aggregation (this function does not require any sub-indices and any standardization of the variables). This index ranged from 0 to 3, the latter being the ideal value (Akhtar et al. 2021 ; Kachroud et al. 2019a , b ; Said et al. 2004 ; Uddin et al. 2021 ).

The Malaysian WQI (MWQI) was carried out in 2007, including six variables: DO, BOD, Chemical Oxygen Demand (COD), Ammonia Nitrogen, suspended solids and pH. For each variable, a curve was established to transform the actual value of the variable into a non-dimensional sub-index value.

The next step is to determine the weighting of the variables by considering the experts panel opinions. The final score is determined using the additive aggregation formula (where sub-indices values and their weightings are summed), extending from 0 (polluted) to 100 (clean) (Uddin et al. 2021 ).

The Hanh and Almeida indices were established respectively in 2010 on surface water in Vietnam and 2012 on the Potrero de los Funes in Argentina, based on 8 (color, suspended solids, DO, BOD, COD, chloride, total coliforms and orthophosphate) and 10 (color, pH, COD, fecal coliforms, total coliforms, total phosphate, nitrates, detergent, enterococci and Escherichia coli .) water quality variables. Both indices were based on rating curve- based sum-indexing system (Uddin et al. 2021 ).

The most recent developed WQI model in the literature was carried out in 2017. This index tried to reduce uncertainty present in other water quality indices. The West Java Water Quality Index (WJWQI) applied in the Java Sea in Indonesia was based on thirteen crucial water quality variables: temperature, suspended solids, COD, DO, nitrite, total phosphate, detergent, phenol, chloride, Zn, Pb, mercury (Hg) and fecal coliforms. Using two screening steps (based on statistical assessment), parameter (variable) redundancy was determined to only 9: temperature, suspended solids, COD, DO, nitrite, total phosphate, detergent, phenol and chloride. Sub-indices were obtained for those nine variables and weights were allocated based on expert opinions, using the same multiplicative aggregation as the NSFWQI. The WJWQI suggested 5 quality classes ranging from poor (5–25) to excellent (90–100) (Uddin et al. 2021 ).

2.2 Phases of WQI development

Mainly, WQI concept is based on many factors as displayed in Fig.  1 and described in the following steps:

Phases of WQI development

Parameter selection for measurement of water quality (Shah and Joshi 2017 ):

The selection is carried out based on the management objectives and the environmental characteristics of the research area (Yan et al. 2015 ). Many variables are recommended, since they have a considerable impact on water quality and derive from 5 classes namely, oxygen level, eutrophication, health aspects, physical characteristics and dissolved substances (Tyagi et al. 2013 ).

Transformation of the raw data parameter into a common scale (Paun et al. 2016 ):

Different statistical approach can be used for transformation, all parameters are transformed from raw data that have different dimensions and units (ppm, saturation, percentage etc.) into a common scale, a non-dimensional scale and sub-indices are generated (Poonam et al. 2013 ; Tirkey et al. 2015 ).

Providing weights to the parameters (Tripathi and Singal 2019 ):

Weights are assigned to each parameter according to their importance and their impact on water quality, expert opinion is needed to assign weights (Tirkey et al. 2015 ). Weightage depends on the permissible limits assigned by International and National agencies in water drinking (Shah and Joshi 2017 ).

Aggregation of sub-index values to obtain the final WQI:

WQI is the sum of rating and weightage of all the parameters (Tripathi and Singal 2019 ).

It is important to note that in some indices, statistical approaches are commonly used such as factor analysis (FA), principal component analysis (PCA), discriminant analysis (DA) and cluster analysis (CA). Using these statistical approaches improves accuracy of the index and reduce subjective assumptions (Tirkey et al. 2015 ).

2.3 Evolution of WQI research

2.3.1 per year.

According to Scopus ( 2022 ), the yearly evolution of WQI's research is illustrated in Fig.  2 (from 1978 till 2022).

Evolution of WQI research per year (Scopus 2022 )

Overall, it is clear that the number of research has grown over time, especially in the most recent years. The number of studies remained shy between 1975 and 1988 (ranging from 1 to 13 research). In 1998, the number improved to 46 studies and increased gradually to 466 publications in 2011.The WQI's studies have grown significantly over the past decade, demonstrating that the WQI has become a significant research topic with the goal of reaching its maximum in 2022 (1316 studies) (Scopus, 2022 ).

2.3.2 Per country

In Fig.  3 , the development of WQI research is depicted visually per country from 1975 to 2022.

Evolution of WQI research per country (Scopus 2022 )

According to Scopus ( 2022 ), the top three countries were China, India and the United States, with 2356, 1678 and 1241 studies, respectively. Iran, Brazil, and Italy occupy the fourth, fifth, and sixth spots, respectively (409, 375 and 336 study). Malaysia and Spain have approximately the same number of studies, respectively 321 and 320 study. The studies in the remaining countries decrease gradually from 303 document in Spain to 210 documents in Turkey. This demonstrates that developing nations, like India, place a high value on the development of water quality protection even though they lack strong economic power, cutting-edge technology, and a top-notch scientific research team. This is because water quality is crucial to the long-term social and economic development of those nations (Zhang 2019 ).

2.4 Different methods for WQI determination

Water quality indices are tools to determine water quality. Those indices demand basic concepts and knowledge about water issues (Singh et al. 2013 ). There are many water quality indices such as the: National Sanitation Foundation Water Quality Index (NSFWQI), Canadian Council of Ministers of Environment Water Quality Index (CCMEWQI), Oregon Water Quality Index (OWQI), and Weight Arithmetic Water Quality Index (WAWQI) (Paun et al. 2016 ).

These water quality indices are applied in particular areas, based on many parameters compared to specific regional standards. Moreover, they are used to illustrate annual cycles, spatio-temporal variations and trends in water quality (Paun et al. 2016 ). That is to say that, these indices reflect the rank of water quality in lakes, streams, rivers, and reservoirs (Kizar 2018 ).

Accordingly, in this section a general review of available worldwide used indices is presented.

2.4.1 National sanitation foundation (NSFWQI)

The NSFWQI was developed in 1970 by the National Sanitation Foundation (NSF) of the United States (Hamlat et al. 2017 ; Samadi et al. 2015 ). This WQI has been widely field tested and is used to calculate and evaluate the WQI of many water bodies (Hamlat et al. 2017 ). However, this index belongs to the public indices group. It represents a general water quality and does not take into account the water’s use capacities, furthermore, it ignores all types of water consumption in the evaluation process (Bharti and Katyal 2011 ; Ewaid 2017 ).

The NSFWQI has been widely applied and accepted in Asian, African and European countries (Singh et al. 2013 ), and is based on the analysis of nine variables or parameters, such as, BOD, DO, Nitrate (NO 3 ), Total Phosphate (PO 4 ), Temperature, Turbidity, Total Solids(TS), pH, and Fecal Coliforms (FC).

Some of the index parameters have different importance, therefore, a weighted mean for each parameter is assigned, based on expert opinion which have grounded their opinions on the environmental significance, the recommended principles and uses of water body and the sum of these weights is equal to 1 (Table 1 ) (Ewaid 2017 ; Uddin et al. 2021 ).

Due to environmental issues, the NSFWQI has changed overtime. The TS parameter was substituted by the Total Dissolved Solids (TDS) or Total Suspended Solids (TSS), the Total Phosphate by orthophosphate, and the FC by E. coli (Oliveira et al. 2019 ).

The mathematical expression of the NSFWQI is given by the following Eq. ( 1 ) (Tyagi et al. 2013 ):

where, Qi is the sub-index for ith water quality parameter. Wi is the weight associated with ith water quality parameter. n is the number of water quality parameters.

This method ranges from 0 to 100, where 100 represents perfect water quality conditions, while zero indicates water that is not suitable for the use and needs further treatment (Samadi et al. 2015 ).

The ratings are defined in the following Table 2 .

In 1972, the Dinius index (DWQI) happened to be the second modified version of the NSF (USA). Expended in 1987 using the Delphi method, the DWQI included twelve parameters (with their assigned weights): Temperature (0.077), color (0.063), pH (0.077), DO (0.109), BOD (0.097), EC (0.079), alkalinity (0.063), chloride (0.074), coliform count (0.090), E. coli (0.116). total hardness (0.065) and nitrate (0.090). Without any conversion process, the DWQI used the measured variable concentrations directly as the sub-index values (Kachroud et al. 2019b ; Uddin et al. 2021 ).

Sukmawati and Rusni assessed in 2018 the water quality in Beratan lake (Bali), choosing five representative stations for water sampling representing each side of the lake, using the NSFWQI. NSFWQI’s nine parameters mentioned above were measured in each station. The findings indicated that the NSFWQI for the Beratan lake was seventy-eight suggesting a good water quality. Despite this, both pH and FC were below the required score (Sukmawati and Rusni 2019 ).

The NSFWQI indicated a good water quality while having an inadequate value for fecal coliforms and pH. For that reason, WQIs must be adapted and developed so that any minor change in the value of any parameter affects the total value of the water quality index.

A study conducted by Zhan et al. ( 2021 ) , concerning the monitoring of water quality and examining WQI trends of raw water in Macao (China) was established from 2002 to 2019 adopting the NSFWQI. NSFWQI's initial model included nine parameters (DO, FC, pH, BOD, temperature, total phosphates, and nitrates), each parameter was given a weight and the parameters used had a significant impact on the WQI calculation outcomes. Two sets of possible parameters were investigated in this study in order to determine the impact of various parameters. The first option was to keep the original 9-parameter model, however, in the second scenario, up to twenty-one parameters were chosen, selected by Principal Component Analysis (PCA).

The latter statistical method was used to learn more about the primary elements that contributed to water quality variations, and to calculate the impact of each attribute on the quality of raw water. Based on the PCA results, the 21-parameter model was chosen. The results showed that the quality of raw water in Macao has been relatively stable in the period of interest and appeared an upward trend overall. Furthermore, the outcome of environmental elements, such as natural events, the region's hydrology and meteorology, can have a significant impact on water quality. On the other hand, Macao's raw water quality met China's Class III water quality requirements and the raw water pollution was relatively low. Consequently, human activities didn’t have a significant impact on water quality due to effective treatment and protection measures (Zhan et al. 2021 ).

Tampo et al. ( 2022 ) undertook a recent study in Adjougba (Togo), in the valley of Zio River. Water samples were collected from the surface water (SW), ground water (GW) and treated wastewater (TWW), intending to compare the water quality of these resources for irrigation and domestic use.

Hence, WQIs, water suitability indicators for irrigation purposes (WSI-IPs) and raw water quality parameters were compared using statistical analysis (factor analysis and Spearman’s correlation).

Moreover, the results proposed that he water resources are suitable for irrigation and domestic use: TWW suitable for irrigation use, GW suitable for domestic use and SW suitable for irrigation use.

The NSFWQI and overall index of pollution (OPI) parameters were tested, and the results demonstrated that the sodium absorption ratio, EC, residual sodium carbonate, Chloride and FC are the most effective parameters for determining if water is suitable for irrigation.

On the other hand, EC, DO, pH, turbidity, COD, hardness, FC, nitrates, national sanitation foundation's water quality index (NSFWQI), and overall index of pollution (OPI) are the most reliable in the detection of water suitability for domestic use (Tampo et al. 2022 ).

Following these studies, it is worth examining the NSFWQI. This index can be used with other WQI models in studies on rivers, lakes etc., since one index can show different results than another index, in view of the fact that some indices might be affected by other variations such as seasonal variation.

Additionally, the NSFWQI should be developed and adapted to each river, so that any change in any value will affect the entire water quality. It is unhelpful to have a good water quality yet a low score of a parameter that can affect human health (case of FC).

2.4.2 Canadian council of ministers of the environment water quality index (CCMEWQI)

The Canadian Water Quality Index adopted the conceptual model of the British Colombia Water Quality Index (BCWQI), based on relative sub-indices (Kizar 2018 ).

The CCMEWQI provides a water quality assessment for the suitability of water bodies, to support aquatic life in specific monitoring sites in Canada (Paun et al. 2016 ). In addition, this index gives information about the water quality for both management and the public. It can furthermore be applied in many water agencies in various countries with slight modification (Tyagi et al. 2013 ).

The CCMEWQI method simplifies the complex and technical data. It tests the multi-variable water quality data and compares the data to benchmarks determined by the user (Tirkey et al. 2015 ). The sampling protocol requires at least four parameters sampled at least four times but does not indicate which ones should be used; the user must decide ( Uddin et al. 2021 ). Yet, the parameters may vary from one station to another (Tyagi et al. 2013 ).

After the water body, the objective and the period of time have been defined the three factors of the CWQI are calculated (Baghapour et al. 2013 ; Canadian Council of Ministers of the Environment 1999 ):

The scope (F1) represents the percentage of variables that failed to meet the objective (above or below the acceptable range of the selected parameter) at least once (failed variables), relative to the total number of variables.

The frequency (F2) represents the percentage of tests which do not meet the objectives (above or below the acceptable range of the selected parameter) (failed tests).

The amplitude represents the amount by which failed tests values did not meet their objectives (above or below the acceptable range of the selected parameter). It is calculated in three steps.

The excursion is termed each time the number of an individual parameter is further than (when the objective is a minimum, less than) the objective and is calculated by two Eqs. ( 4 , 5 ) referring to two cases. In case the test value must not exceed the objective:

For the cases in which the test value must not fall below the objective:

The normalized sum of excursions, or nse , is calculated by summing the excursions of individual tests from their objectives and diving by the total number of tests (both meetings and not meeting their objectives):

F3 is then calculated an asymptotic function that scales the normalized sum of the excursions from objectives (nse) to yield a range between 0 and 100:

Finally, the CMEWQI can be obtained from the following equation, where the index changes in direct proportion to changes in all three factors.

where 1.732 is a scaling factor and normalizes the resultant values to a range between 0 and 100, where 0 refers to the worst quality and one hundred represents the best water quality.

Once the CCME WQI value has been determined, water quality in ranked as shown in Table 3

Ramírez-Morales et al. ( 2021 ) investigated in their study the measuring of pesticides and water quality indices in three agriculturally impacted micro catchments in Costa Rica between 2012 and 2014. Surface water and sediment samples were obtained during the monitoring experiment.

The specifications of the water included: Pesticides, temperature, DO, oxygen saturation, BOD, TP, NO3, sulfate, ammonium, COD, conductivity, pH and TSS.

Sediment parameters included forty-two pesticides with different families including carbamate, triazine, organophosphate, phthalimide, pyrethroid, uracil, benzimidazole, substituted urea, organochlorine, imidazole, oxadiazole, diphenyl ether and bridged diphenyl.

WQIs are effective tools since they combine information from several variables into a broad picture of the water body's state. Two WQIs were calculated using the physicochemical parameters: The Canadian Council of Ministers of the Environment (CCME) WQI and the National Sanitation Foundation (NSF) WQI.

These were chosen since they are both extensively used and use different criteria to determine water quality: The NSF WQI has fixed parameters, weights, and threshold values, whereas the CCME has parameters and threshold values that are customizable.

The assessment of water quality using physico-chemical characteristics and the WQI revealed that the CCME WQI and the NSF WQI have distinct criteria. CCME WQI categorized sampling point as marginal/bad quality, while most sampling locations were categorized as good quality in the NSF WQI. Seemingly, the water quality classifications appeared to be affected by seasonal variations: during the wet season, the majority of the CCME WQI values deteriorated, implying that precipitation and runoff introduced debris into the riverbed. Thus, it’s crucial to compare WQIs because they use various factors, criteria, and threshold values, which might lead to different outcomes (Ramírez-Morales et al. 2021 ).

Yotova et al. ( 2021 ) directed an analysis on the Mesta River located between Greece and Bulgaria. The Bulgarian section of the Mesta River basin, which is under the supervision of the West-Aegean Region Basin Directorate, was being researched. The goal was to evaluate the surface water quality of ten points of the river using a novel approach that combines composite WQI developed by the CCME and Self organizing map (SOM) on the required monitoring data that include: DO, pH, EC, ammonium, nitrite, nitrate, total phosphate, BOD and TSS.

The use of WQI factors in SOM calculations allows for the identification of specific WQI profiles for various object groups and identifying groupings of river basin which have similar sampling conditions. The use of both could reveal and estimate the origin and magnitude of anthropogenic pressure. In addition, it might be determined that untreated residential wastewaters are to blame for deviations from high quality requirements in the Mesta River catchment.

Interestingly, this study reveals that WQI appear more accurate and specific when combined with a statistical test such as the SOM (Yotova et al. 2021 ).

2.4.3 Oregon water quality index (OWQI)

The Oregon Water Quality Index is a single number that creates a score to evaluate the water quality of Oregon’s stream and apply this method in other geographical region (Hamlat et al. 2017 ; Singh et al. 2013 ). The OWQI was widely accepted and applied in Oregon (USA) and Idaho (USA) (Sutadian et al. 2016 ).

Additionally, the OWQI is a variant of the NSFWQI, and is used to assess water quality for swimming and fishing, it is also used to manage major streams (Lumb et al. 2011b ). Since the introduction of the OWQI in 1970, the science of water quality has improved noticeably, and since 1978, index developers have benefited from increasing understanding of stream functionality (Bharti and Katyal 2011 ). The Oregon index belongs to the specific consumption indices group. It is a water classification based on the kind of consumption and application such as drinking, industrial, etc. (Shah and Joshi 2017 ).

The original OWQI dropped off in 1983, due to excessive resources required for calculating and reporting results. However, improvement in software and computer hardware availability, in addition to the desire for an accessible water quality information, renewed interest in the index (Cude 2001 ).

Simplicity, availability of required quality parameters, and the determination of sub-indexes by curve or analytical relations are some advantages of this approach (Darvishi et al. 2016a ). The process combines eight variables including temperature, dissolved oxygen (percent saturation and concentration), biochemical oxygen demand (BOD), pH, total solids, ammonia and nitrate nitrogen, total phosphorous and bacteria (Brown 2019 ). Equal weight parameters were used for this index and has the same effect on the final factor (Darvishi et al. 2016a ; Sutadian et al. 2016 ).

The Oregon index is calculated by the following Eq.  9 (Darvishi et al. 2016a ):

where,n is the number of parameters (n = 8) SI i is the value of parameter i.

Furthermore, the OWQI scores range from 10 for the worse case to 100 as the ideal water quality illustrated in the following Table 4 (Brown 2019 ).

Kareem et al. ( 2021 ) using three water quality indices, attempted to analyze the Euphrates River (Iraq) water quality for irrigation purposes in three different stations: WAWQI, CCMEWQI AND OWQI.

For fifteen parameters, the annual average value was calculated, which included: pH, BOD, Turbidity, orthophosphate, Total Hardness, Sulphate, Nitrate, Alkalinity, Potassium Sodium, Magnesium, Chloride, DO, Calcium and TDS.

The OWQI showed that the river is “very poor”, and since the sub-index of the OWQI does not rely on standard-parameter compliance, there are no differences between the two inclusion and exclusion scenarios, which is not the case in both WAWQI and CCMEWQI (Kareem et al. 2021 ).

Similarly, the OWQI showed a very bad quality category, and it is unfit for human consumption, compared to the NSFWQI and Wilcox indices who both showed a better quality of water in Darvishi et al., study conducted on the Talar River (Iran) (Darvishi et al. 2016b ).

2.4.4 Weighted arithmetic water quality index (WAWQI)

The weighted arithmetic index is used to calculate the treated water quality index, in other terms, this method classifies the water quality according to the degree of purity by using the most commonly measured water quality variables (Kizar 2018 ; Paun et al. 2016 ).This procedure has been widely used by scientists (Singh et al. 2013 ).

Three steps are essential in order to calculate the WAWQI:

Further quality rating or sub-index was calculated using the following equation (Jena et al. 2013 ):

Qn is the quality rating for the nth water quality parameter.

Vn is the observed value of the nth parameter at a given sampling station.

Vo is the ideal value of the nth parameter in a pure water.

Sn is the standard permissible value of the nth parameter.

The quality rating or sub index corresponding to nth parameter is a number reflecting the relative value of this parameter in polluted water with respect to its permissible standard value (Yogendra & Puttaiah 2008 ).

The unit weight was calculated by a value inversely proportional to the recommended standard values (Sn) of the corresponding parameters (Jena et al. 2013 ):

Wn is the unit weight for the nth parameter.

K is the constant of proportionality.

Sn is the standard value of the nth parameter.

The overall WQI is the aggregation of the quality rating (Qn) and the unit weight (Wn) linearly (Jena et al. 2013 ):

After calculating the WQI, the measurement scale classifies the water quality from “unsuitable water” to “excellent water quality” as given in the following Table 5 .

Sarwar et al. ( 2020 ) carried out a study in Chaugachcha and Manirampur Upazila of Jashore District (Bangladesh). The goal of this study was to determine the quality of groundwater and its appropriateness for drinking, using the WAWQI including nine parameters: turbidity, EC, pH, TDS, nitrate, ammonium, sodium, potassium and iron. Many samplings point was taken from Chaugachcha and Manirampur, and WQI differences were indicated (ranging from very poor to excellent). These variations in WQI were very certainly attributable to variances in geographical location. Another possibility could be variations in the parent materials from which the soil was created, which should be confirmed using experimental data. It is worth mentioning that every selected parameter was taken into consideration during calculation. Similarly, the water quality differed in Manirampur due to the elements contained in the water samples that had a big impact on the water quality (Sarwar et al. 2020 ).

In 2021, García-Ávila et al. undertook a comparative study between the CCMEWQI and WAWQI for the purpose of determining the water quality in the city of Azogues (Ecuador). Twelve parameters were analyzed: pH, turbidity, color, total dissolved solids, electrical conductivity, total hardness, alkalinity, nitrates, phosphates, sulfates, chlorides and residual chlorine over 6 months. The average WAWQI value was calculated suggesting that 16.67% of the distribution system was of 'excellent' quality and 83.33% was of 'good' quality, while the CCMEWQI indicated that 100% of the system was of ‘excellent’ quality.

This difference designated that the parameters having a low maximum allowable concentration have an impact on WAWQI and that WAWQI is a valuable tool to determine the quality of drinking water and have a better understanding of it (García-Ávila et al. 2022a , b ).

2.4.5 Additional water quality indices

The earliest WQI was based on a mathematical function that sums up all sub-indices, as detailed in the 2.1. History of water quality concept section (Aljanabi et al. 2021 ). The Dinius index (1972), the OWQI (1980), and the West Java index (2017) were later modified from the Horton index, which served as a paradigm for later WQI development (Banda and Kumarasamy 2020 ).

Based on eleven physical, chemical, organic, and microbiological factors, the Scottish Research Development Department (SRDDWQI) created in 1976 was based on the NSFWQI and Delphi methods used in Iran, Romania, and Portugal. Modified into the Bascaron index (1979) in Spain, which was based on 26 parameters that were unevenly weighted with a subjective representation that allowed an overestimation of the contamination level. The House index (1989) in the UK valued the parameters directly as sub-indices. The altered version was adopted as Croatia's Dalmatian index in 1999.

The Ross WQI (1977) was created in the USA using only 4 parameters and did not develop into any further indices.

In 1982, the Dalmatian and House WQI were used to create the Environmental Quality Index, which is detailed in Sect.  2.1 . This index continues to be difficult to understand and less powerful than other indices (Lumb et al. 2011a ; Uddin et al. 2021 ).

The Smith index (1990), is based on 7 factors and the Delphi technique in New Zealand, attempts to eliminate eclipsing difficulties and does not apply any weighting, raising concerns about the index's accuracy (Aljanabi et al. 2021 ; Banda and Kumarasamy 2020 ; Uddin et al. 2021 ).

The Dojildo index (1994) was based on 26 flexible, unweighted parameters and does not represent the water's total quality.

With the absence of essential parameters, the eclipse problem is a type of fixed-parameter selection. The Liou index (2004) was established in Taiwan to evaluate the Keya River based on 6 water characteristics that were immediately used into sub-index values. Additionally, because of the aggregation function, uncertainty is unrelated to the lowest sub-index ranking (Banda and Kumarasamy 2020 ; Uddin et al. 2021 ).

Said index (2004) assessed water quality using only 4 parameters, which is thought to be a deficient number for accuracy and a comprehensive picture of the water quality. Furthermore, a fixed parameter system prevents the addition of any new parameters.

Later, the Hanh index (2010), which used hybrid aggregation methods and gave an ambiguous final result, was developed from the Said index.

In addition to eliminating hazardous and biological indicators, the Malaysia River WQI (MRWQI developed in the 2.1 section) (2007) was an unfair and closed system that was relied on an expert's judgment, which is seen as being subjective and may produce ambiguous findings (Banda and Kumarasamy 2020 ; Uddin et al. 2021 ).

Table illustrated the main data of the studies published during 2020–2022 on water quality assessments and their major findings:

2.5 Advantages and disadvantages of the selected water quality indices

A comparison of the selected indices is done by listing the advantages and disadvantages of every index listed in the Table 7 below.

2.6 New attempts of WQI studies

Many studies were conducted to test the water quality of rivers, dams, groundwater, etc. using multiple water quality indices throughout the years. Various studies have been portrayed here in.

Massoud ( 2012 ) observed during a 5-year monitoring period, in order to classify the spatial and temporal variability and classify the water quality along a recreational section of the Damour river using a weighted WQI from nine physicochemical parameters measured during dry season. The WWQI scale ranged between “very bad” if the WQI falls in the range 0–25, to “excellent” if it falls in the range 91–100. The results revealed that the water quality of the Damour river if generally affected by the activities taking place along the watershed. The best quality was found in the upper sites and the worst at the estuary, due to recreational activities. If the Damour river is to be utilized it will require treatment prior any utilization (Massoud 2012 ).

Rubio-Arias et al. ( 2012 ) conducted a study in the Luis L. Leon dam located in Mexico. Monthly samples were collected at 10 random points of the dam at different depths, a total of 220 samples were collected and analyzed. Eleven parameters were considered for the WQI calculation, and WQI was calculated using the Weighted WQI equation and could be classified according to the following ranges: < 2.3 poor; from 2.3 to 2.8 good; and > 2.8 excellent. Rubio-Arias et al., remarked that the water could be categorized as good during the entire year. Nonetheless, some water points could be classified as poor due to some anthropogenic activities such as intensive farming, agricultural practices, dynamic urban growth, etc. This study confirms that water quality declined after the rainy season (Rubio-Arias et al. 2012 ).

In the same way, Haydar et al. ( 2014 ) evaluated the physical, chemical and microbiological characteristics of water in the upper and lower Litani basin, as well as in the lake of Qaraaoun. The samples were collected during the seasons of 2011–2012 from the determined sites and analyzed by PCA and the statistical computations of the physico-chemical parameters to extract correlation between variables. Thus, the statistical computations of the physico-chemical parameters showed a correlation between some parameters such as TDS, EC, Ammonium, Nitrate, Potassium and Phosphate. Different seasons revealed the presence of either mineral or anthropogenic or both sources of pollution caused by human interference from municipal wastewater and agricultural purposes discharged into the river. In addition, temporal effects were associated with seasonal variations of river flow, which caused the dilution if pollutants and, hence, variations in water quality (Haydar et al. 2014 ).

Another study conducted by Chaurasia et al., ( 2018 ), proposed a groundwater quality assessment in India using the WAWQI. Twenty-two parameters were taken into consideration for this assessment, however, only eight important parameters were chosen to calculate the WQI. The rating of water quality shows that the ground water in 20% of the study area is not suitable for drinking purpose and pollution load is comparatively high during rainy and summer seasons. Additionally, the study suggests that priority should be given to water quality monitoring and its management to protect the groundwater resource from contamination as well as provide technology to make the groundwater fit for domestic and drinking (Chaurasia et al. 2018 ).

Daou et al. ( 2018 ) evaluated the water quality of four major Lebanese rivers located in the four corners of Lebanon: Damour, Ibrahim, Kadisha and Orontes during the four seasons of the year 2010–2011. The assessment was done through the monitoring of a wide range of physical, chemical and microbiological parameters, these parameters were screened using PCA. PCA was able to discriminate each of the four rivers according to a different trophic state. The Ibrahim River polluted by mineral discharge from marble industries in its surroundings, as well as anthropogenic pollutants, and the Kadisha river polluted by anthropogenic wastes seemed to have the worst water quality. This large-scale evaluation of these four Lebanese rivers can serve as a water mass reference model (Daou et al. 2018 ).

Moreover, some studies compared many WQI methods. Kizar ( 2018 ), carried out a study on Shatt Al-Kufa in Iraq, nine locations and twelve parameters were selected. The water quality was calculated using two methods, the WAWQI and CWQI. The results revealed the same ranking of the river for both methods, in both methods the index decreased in winter and improved in other seasons (Kizar 2018 ).

On the other hand, Zotou et al. ( 2018 ), undertook a research on the Polyphytos Reservoir in Greece, taking into consideration thirteen water parameters and applying 5 WQIs: Prati’s Index of Pollution (developed in 1971, based on thirteen parameter and mathematical functions to convert the pollution concentration into new units. The results of PI classified water quality into medium classes (Gupta and Gupta 2021 ). Bhargava’s WQI (established in 1983, the BWQI categorize the parameters according to their type: bacterial indicators, heavy metals and toxins, physical parameters and organic and inorganic substances. The BWQI tends to classify the water quality into higher quality classes, which is the case in the mentioned study (Gupta and Gupta 2021 ). Oregon WQI, Dinius second index, Weighted Arithmetic WQI, in addition to the NSF and CCMEWQI. The results showed that Bhargava and NSF indices tend to classify the reservoir into superior quality classes, Prati’s and Dinius indices fall mainly into the middle classes of the quality ranking, while CCME and Oregon could be considered as “stricter” since they give results which range steadily between the lower quality classes (Zotou et al. 2018 ).

In their study, Ugochukwu et al. ( 2019 ) investigated the effects of acid mine drainage, waste discharge into the Ekulu River in Nigeria and other anthropogenic activities on the water quality of the river. The study was performed between two seasons, the rainy and dry season. Samples were collected in both seasons, furthermore, the physic-chemistry parameters and the heavy metals were analyzed. WQI procedure was estimated by assigning weights and relative weights to the parameters, ranking from “excellent water” (< 50) to “unsuitable for drinking” (> 300). The results showed the presence of heavy metals such as lead and cadmium deriving from acid mine drainage. In addition, the water quality index for all the locations in both seasons showed that the water ranked from “very poor” to “unsuitable for drinking”, therefore the water should be treated before any consumption, and that enough information to guide new implementations for river protection and public health was provided (Ugochukwu et al. 2019 ).

The latest study in Lebanon related to WQI was carried out by El Najjar et al. ( 2019 ), the purpose of the study was to evaluate the water quality of the Ibrahim River, one of the main Lebanese rivers. The samples were collected during fifteen months, and a total of twenty-eight physico-chemical and microbiological parameters were tested. The parameters were reduced to nine using the Principal Component Analysis (PCA) and Pearson Correlation. The Ibrahim WQI (IWQI) was finally calculated using these nine parameters and ranged between 0 and 25 referring to a “very bad” water quality, and between 91 and 100 referring to an “excellent” water quality. The IWQI showed a seasonal variation, with a medium quality during low -water periods and a good one during high-water periods (El Najjar et al. 2019 ).

3 Conclusion

WQI is a simple tool that gives a single value to water quality taking into consideration a specific number of physical, chemical, and biological parameters also called variables in order to represent water quality in an easy and understandable way. Water quality indices are used to assess water quality of different water bodies, and different sources. Each index is used according to the purpose of the assessment. The study reviewed the most important indices used in water quality, their mathematical forms and composition along with their advantages and disadvantages. These indices utilize parameters and are carried out by experts and government agencies globally. Nevertheless, there is no index so far that can be universally applied by water agencies, users and administrators from different countries, despite the efforts of researchers around the world (Paun et al. 2016 ). The study also reviewed some attempts on different water bodies utilizing different water quality indices, and the main studies performed in Lebanon on Lebanese rivers in order to determine the quality of the rivers (Table 6 ).

As mentioned in the article (Table 7 ); WQIs may undergo some limitations. Some indices could be biased, others are not specific, and they may not get affected by the value of an important parameter. Therefore, there is no interaction between the parameters.

Moreover, many studies exhibited a combination between WQIs and statistical techniques and analysis (such as the PCA, Pearson’s correlation etc.). with a view to obtain the relation between the parameters and which parameter might affect the water quality.

In other research, authors compared many WQIs to check the difference of water quality according to each index. Each index can provide different values depending on the sensitivity of the parameter. For that reason, WQIs should be connected to scientific advancements to develop and elaborate the index in many ways (example: ecologically). Therefore, an advanced WQI should be developed including first statistical techniques, such as Pearson correlation and multivariate statistical approach mainly Principal Component Analysis (PCA) and Cluster Analysis (CA), in order to determine secondly the interactions and correlations between the parameters such as TDS and EC, TDS and total alkalinity, total alkalinity and chloride, temperature and bacteriological parameters, consequently, a single parameter could be selected as representative of others. Finally, scientific and technological advancement for future studies such as GIS techniques, fuzzy logic technology to assess and enhance the water quality indices and cellphone-based sensors for water quality monitoring should be used.

Akhtar N, Ishak MIS, Ahmad MI, Umar K, Md Yusuff MS, Anees MT, Qadir A, Ali Almanasir YK (2021) Modification of the Water Quality Index (WQI) process for simple calculation using the Multi-Criteria Decision-Making (MCDM) Method: a review. Water 13:905. https://doi.org/10.3390/w13070905

Article   CAS   Google Scholar  

Alexakis DE (2020) Meta-evaluation of water quality indices application into groundwater resources. Water 12:1890. https://doi.org/10.3390/w12071890

Article   Google Scholar  

Aljanabi ZZ, Jawad Al-Obaidy AHM, Hassan FM (2021) A brief review of water quality indices and their applications. IOP Conf Ser: Earth Environ Sci 779:012088. https://doi.org/10.1088/1755-1315/779/1/012088

Al-Kareem SA, ALKzwini RS (2022) Statistical analysis for water quality index for Shatt-Al-Hilla river in Babel city. Water Pract Technol 17:567–586. https://doi.org/10.2166/wpt.2022.004

Baghapour MA, Nasseri S, Djahed B (2013) Evaluation of Shiraz wastewater treatment plant effluent quality for agricultural irrigation by Canadian Water Quality Index (CWQI). Iran J Environ Health Sci Eng 10:27. https://doi.org/10.1186/1735-2746-10-27

Banda T, Kumarasamy M (2020) Development of a universal water quality index (UWQI) for South African River Catchments. Water 12:1534. https://doi.org/10.3390/w12061534

Betis H, St-Hilaire A, Fortin C, Duchesne S (2020) Development of a water quality index for watercourses downstream of harvested peatlands. Water Qual Res J 55:119–131. https://doi.org/10.2166/wqrj.2020.007

Bharti N, Katyal D (2011) Water quality indices used for surface water vulnerability assessment. Int J Environ Sci 2:154–173

CAS   Google Scholar  

Britto FB, do Vasco AN, Aguiar Netto ADO, Garcia CAB, Moraes GFO, Silva MGD (2018) Surface water quality assessment of the main tributaries in the lower São Francisco River, Sergipe. RBRH 23:6–23. https://doi.org/10.1590/2318-0331.231820170061

Brown D (2019) Oregon Water Quality Index: background, analysis and usage. State of Oregon Department of Environmental Quality, Laboratory and Environmental Assessment Program

Brown RM, McClelland NI, Deininger RA, Tozer RG (1970) A water quality index-do we dare. Water Sew Work 117:339–343

Calmuc M, Calmuc V, Arseni M, Topa C, Timofti M, Georgescu LP, Iticescu C (2020) A comparative approach to a series of physico-chemical quality indices used in assessing water quality in the lower Danube. Water 12:3239. https://doi.org/10.3390/w12113239

Canadian Council of Ministers of the Environment 2001 (1999) Canadian water quality guidelines for the protection of aquatic life: CCME Water Quality Index 1.0, Technical Report. Canadian environmental quality guidelines, Canadian Council of Ministers of the Environment, Winnipeg

Chaurasia AK, Pandey HK, Tiwari SK, Prakash R, Pandey P, Ram A (2018) Groundwater quality assessment using Water Quality Index (WQI) in parts of Varanasi District, Uttar Pradesh, India. J Geol Soc India 92:76–82. https://doi.org/10.1007/s12594-018-0955-1

Chen L, Tian Z, Zou K (2020) Water quality evaluation based on the water quality index method in Honghu Lake: one of the largest shallow lakes in the Yangtze River Economic Zone. Water Supp 20:2145–2155. https://doi.org/10.2166/ws.2020.111

Choi B, Choi SS (2021) Integrated hydraulic modelling, water quality modelling and habitat assessment for sustainable water management: a case study of the Anyang-Cheon stream. Korea Sustain 13:4330. https://doi.org/10.3390/su13084330

Choque-Quispe D, Froehner S, Palomino-Rincón H, Peralta-Guevara DE, Barboza-Palomino GI, Kari-Ferro A, Zamalloa-Puma LM, Mojo-Quisani A, Barboza-Palomino EE, Zamalloa-Puma MM, Martínez-Huamán EL, Calla-Florez M, Aronés-Medina EG, Solano-Reynoso AM, Choque-Quispe Y (2022) Proposal of a water-quality index for high Andean Basins: application to the Chumbao River, Andahuaylas. Peru Water 14:654. https://doi.org/10.3390/w14040654

Cong Thuan N (2022) Assessment of surface water quality in the Hau Giang province using geographical information system and statistical Aaproaches. J Ecol Eng 23:265–276. https://doi.org/10.12911/22998993/151927

Cristable RM, Nurdin E, Wardhana W (2020) Water quality analysis of Saluran Tarum Barat, West Java, based on National Sanitation Foundation-Water Quality Index (NSF-WQI). IOP Conf Ser: Earth Environ Sci 481:012068. https://doi.org/10.1088/1755-1315/481/1/012068

Cude CG (2001) Oregon Water Quality Index a tool for evaluating water quality management effectiveness. J Am Water Resour as 37:125–137. https://doi.org/10.1111/j.1752-1688.2001.tb05480.x

Da Silveira VR, Kunst Valentini MH, dos Santos GB, Nadaleti WC, Vieira BM (2021) Assessment of the water quality of the Mirim Lagoon and the São Gonçalo channel through qualitative indices and statistical methods. Water Air Soil Poll 232:217. https://doi.org/10.1007/s11270-021-05160-w

Daou C, Salloum M, Legube B, Kassouf A, Ouaini N (2018) Characterization of spatial and temporal patterns in surface water quality: a case study of four major Lebanese rivers. Environ Monit Assess 190:485. https://doi.org/10.1007/s10661-018-6843-8

Darvishi G, Kootenaei FG, Ramezani M, Lotfi E, Asgharnia H (2016a) Comparative investigation of river water quality by OWQI, NSFWQI and Wilcox indexes (Case study: The Talar River – IRAN). Arch Environ Prot 42:41–48. https://doi.org/10.1515/aep-2016-0005

Darvishi G, Kootenaei FG, Ramezani M, Lotfi E, Asgharnia H (2016b) Comparative investigation of river water quality by OWQI, NSFWQI and Wilcox indexes (Case study: The Talar River – IRAN). Arch Environ Prot. https://doi.org/10.1515/aep-2016-0005

De Oliveira MD, de Rezende OLT, de Fonseca JFR, Libânio M (2019) Evaluating the surface water quality index fuzzy and its influence on water treatment. J Water Process Eng 32:100890. https://doi.org/10.1016/j.jwpe.2019.100890

Deep A, Gupta V, Bisht L, Kumar R (2020) Application of WQI for water quality assessment of high-altitude snow-fed sacred Lake Hemkund. Garhwal Himal Sustain Water Resour Manag 6:89. https://doi.org/10.1007/s40899-020-00449-w

Deng L, Shahab A, Xiao H, Li J, Rad S, Jiang J, GuoYu Jiang P, Huang H, Li X, Ahmad B, Siddique J (2021) Spatial and temporal variation of dissolved heavy metals in the Lijiang River, China: implication of rainstorm on drinking water quality. Environ Sci Pollut R 28:68475–68486. https://doi.org/10.1007/s11356-021-15383-3

Dinius SH (1987) Design of an index of water quality. Water Resour Bull 23:833–843

Doderovic M, Mijanovic I, Buric D, Milenkovic M (2020) Assessment of the water quality in the Moraca River basin (Montenegro) using water quality index. Glas Srp Geogr Drus 100:67–81. https://doi.org/10.2298/GSGD2002067D

El Najjar P, Kassouf A, Probst A, Probst JL, Ouaini N, Daou C, El Azzi D (2019) High-frequency monitoring of surface water quality at the outlet of the Ibrahim River (Lebanon): a multivariate assessment. Ecol Indic 104:13–23. https://doi.org/10.1016/j.ecolind.2019.04.061

En-nkhili H, Najy M, Etebaai I, Talbi FZ, El Kharrim K, Belghyti D (2020) Application of water quality index for the assessment of Boudaroua lake in the Moroccan pre-rif. Conference GEOIT4W-2020: 1–5. https://doi.org/10.1145/3399205.3399248

Ewaid SH (2017) Water quality evaluation of Al-Gharraf river by two water quality indices. Appl Water Sci 7:3759–3765. https://doi.org/10.1007/s13201-016-0523-z

Fadel A, Kanj M, Slim K (2021) Water quality index variations in a Mediterranean reservoir: a multivariate statistical analysis relating it to different variables over 8 years. Environ Earth Sci 80:65. https://doi.org/10.1007/s12665-020-09364-x

Fraga MDS, da Silva DD, Reis GB, Guedes HAS, Elesbon AAA (2021) Temporal and spatial trend analysis of surface water quality in the Doce River basin, Minas Gerais, Brazil. Environ Dev Sustain 23:12124–12150. https://doi.org/10.1007/s10668-020-01160-8

Frîncu RM (2021) Long-term trends in water quality indices in the lower Danube and tributaries in Romania (1996–2017). Int J Environ Res Pub He 18:1665. https://doi.org/10.3390/ijerph18041665

Fu D, Chen S, Chen Y, Yi Z (2022) Development of modified integrated water quality index to assess the surface water quality: a case study of Tuo River. China Environ Monit Assess 194:333. https://doi.org/10.1007/s10661-022-09998-3

Galarza E, Cabrera M, Espinosa R, Espitia E, Moulatlet GM, Capparelli MV (2021) Assessing the quality of Amazon aquatic ecosystems with multiple lines of evidence: the case of the Northeast Andean foothills of Ecuador. B Environ Contam Tox 107:52–61. https://doi.org/10.1007/s00128-020-03089-0

Gamvroula DE, Alexakis DE (2022) Evaluating the performance of water quality indices: application in surface water of lake union, Washington State-USA. Hydrology 9:116. https://doi.org/10.3390/hydrology9070116

García-Ávila F, Jiménez-Ordóñez M, Torres-Sánchez J, Iglesias-Abad S, Cabello Torres R, Zhindón-Arévalo C (2022a) Evaluation of the impact of anthropogenic activities on surface water quality using a water quality index and environmental assessment. J Water Land Dev 53:58–67. https://doi.org/10.24425/JWLD.2022.140780

García-Ávila F, Zhindón-Arévalo C, Valdiviezo-Gonzales L, Cadme-Galabay M, Gutiérrez-Ortega H, del Pino LF (2022b) A comparative study of water quality using two quality indices and a risk index in a drinking water distribution network. Environ Technol Rev 11:49–61. https://doi.org/10.1080/21622515.2021.2013955

Ghani J, Ullah Z, Nawab J, Iqbal J, Waqas M, Ali A, Almutairi MH, Peluso I, Mohamed HRH, Shah M (2022) Hydrogeochemical characterization, and suitability assessment of drinking groundwater: application of geostatistical approach and geographic information system. Front Environ Sci 10:874464. https://doi.org/10.3389/fenvs.2022.874464

Giao NT, Nhien HTH, Anh PK, Van Ni D (2021) Classification of water quality in low-lying area in Vietnamese Mekong delta using set pair analysis method and Vietnamese water quality index. Environ Monit Assess 193:319. https://doi.org/10.1007/s10661-021-09102-1

Gomes FDG (2020) Climatic seasonality and water quality in watersheds: a study case in Limoeiro River watershed in the western region of São Paulo State, Brazil. Environ Sci Pollut Res 27:30034–30049. https://doi.org/10.1007/s11356-020-09180-7

Gruss L, Wiatkowski M, Pulikowski K, Kłos A (2021) Determination of changes in the quality of surface water in the river reservoir system. Sustainability 13:3457. https://doi.org/10.3390/su13063457

Gupta S, Gupta SK (2021) A critical review on water quality index tool: genesis, evolution and future directions. Ecol Inform 63:101299. https://doi.org/10.1016/j.ecoinf.2021.101299

Hachi T, Hachi M, Essabiri H, Boumalkha O, Doubi M, Khaffou M, Abba EH (2022) Statistical assessment of the water quality using water quality index and organic pollution index—Case study, Oued Tighza, Morocco. Mor J Chem 10:500–508. https://doi.org/10.48317/IMIST.PRSM/MORJCHEM-V10I3.33139

Hamlat A, Guidoum A, Koulala I (2017) Status and trends of water quality in the Tafna catchment: a comparative study using water quality indices. J Water Reuse Desal 7:228–245. https://doi.org/10.2166/wrd.2016.155

Haydar CM, Nehme N, Awad S, Koubaissy B, Fakih M, Yaacoub A, Toufaily J, Villeras F, Hamieh T (2014) Water quality of the upper Litani river Basin, Lebanon. Physcs Proc 55:279–284. https://doi.org/10.1016/j.phpro.2014.07.040

Horton RK (1965) An index-number system for rating water quality. J Water Pollut Con F 37:292–315

Google Scholar  

Hu L, Chen L, Li Q, Zou K, Li J, Ye H (2022) Water quality analysis using the CCME-WQI method with time series analysis in a water supply reservoir. Water Supply 22:6281–6295. https://doi.org/10.2166/ws.2022.245

Jena V, Dixit S, Gupta S (2013) Assessment of water quality index of industrial area surface water samples. Int J Chemtech Res 5:278–283

Kachroud M, Trolard F, Kefi M, Jebari S, Bourrié G (2019a) Water quality indices: challenges and application limits in the literature. Water 11:361. https://doi.org/10.3390/w11020361

Kachroud M, Trolard F, Kefi M, Jebari S, Bourrié G (2019b) Water quality indices: challenges and application limits in the literature. Water. https://doi.org/10.3390/w11020361

Kareem SL, Jaber WS, Al-Maliki LA, Al-husseiny RA, Al-Mamoori SK, Alansari N (2021) Water quality assessment and phosphorus effect using water quality indices: Euphrates river- Iraq as a case study. Groundw Sustain Dev 14:100630. https://doi.org/10.1016/j.gsd.2021.100630

Khan I (2022) Hydrogeochemical and health risk assessment in and around a Ramsar-designated wetland, the Ganges River Basin, India: implications for natural and human interactions. Environ Monit and Asses 194:1–24. https://doi.org/10.1007/s10661-022-10154-0

Khan R, Saxena A, Shukla S, Sekar S, Goel P (2021) Effect of COVID-19 lockdown on the water quality index of river Gomti, India, with potential hazard of faecal-oral transmission. Environ Sci Pollut R 28:33021–33029. https://doi.org/10.1007/s11356-021-13096-1

Kizar FM (2018) A comparison between weighted arithmetic and Canadian methods for a drinking water quality index at selected locations in shatt al-kufa. IOP Conf Ser: Mater Sci Eng 433:012026. https://doi.org/10.1088/1757-899X/433/1/012026

Kothari V, Vij S, Sharma S, Gupta N (2021) Correlation of various water quality parameters and water quality index of districts of Uttarakhand. Environ Sustain Indic 9:100093. https://doi.org/10.1016/j.indic.2020.100093

Kulisz M, Kujawska J (2021) Application of artificial neural network (ANN) for water quality index (WQI) prediction for the river Warta. Poland. J Phys Conf Ser 2130:012028. https://doi.org/10.1088/1742-6596/2130/1/012028

Kumar A, Bojjagani S, Maurya A, Kisku GC (2022) Spatial distribution of physicochemical-bacteriological parametric quality and water quality index of Gomti river, India. Environ Monit Assess 194:159. https://doi.org/10.1007/s10661-022-09814-y

Kumar P (2018) Simulation of Gomti River (Lucknow City, India) future water quality under different mitigation strategies. Heliyon 4:e01074. https://doi.org/10.1016/j.heliyon.2018.e01074

Kunst Valentini MH, dos Santos GB, Duarte VH, Franz HS, Guedes HAS, Romani RF, Vieira BM (2021) Analysis of the influence of water quality parameters in the final WQI result through statistical correlation methods: Mirim lagoon, RS, Brazil, case study. Water Air Soil Pollut 232:363. https://doi.org/10.1007/s11270-021-05321-x

Lencha SM, Tränckner J, Dananto M (2021) Assessing the water quality of lake Hawassa Ethiopia—trophic state and suitability for anthropogenic uses—applying common water quality indices. Int J Environ Res Pub He 18:8904. https://doi.org/10.3390/ijerph18178904

Liou SM, Lo SL, Wang SH (2004) A generalized water quality index for Taiwan. Environ Monit Assess 96:35–52. https://doi.org/10.1023/B:EMAS.0000031715.83752.a1

Losa MS, González ARM, Hurtado DC (2022) Assessment of water quality with emphasis on trophic status in bathing areas from the central-southern coast of Cuba. Ocean Coast Res 70:e22019. https://doi.org/10.1590/2675-2824070.21096msl

Lumb A, Sharma TC, Bibeault JF (2011) A review of genesis and evolution of Water Quality Index (WQI) and some future directions. Water Qual Expos Hea. https://doi.org/10.1007/s12403-011-0040-0

Lumb LA, Sharma TC, Bibeault JF (2011) A review of genesis and evolution of Water Quality Index (WQI) and some future directions. Water Qual Expos Hea 3:11–24. https://doi.org/10.1007/s12403-011-0040-0

Luo P, Xu C, Kang S, Huo A, Lyu J, Zhou M, Nover D (2021) Heavy metals in water and surface sediments of the Fenghe river basin, China: assessment and source analysis. Water Sci Technol 84:3072–3090. https://doi.org/10.2166/wst.2021.335

Maity S, Maiti R, Senapati T (2022) Evaluation of spatio-temporal variation of water quality and source identification of conducive parameters in Damodar River, India. Environ Monit Assess 194:1–23. https://doi.org/10.1007/s10661-022-09955-0

Makubura R, Meddage DPP, Azamathulla H, Pandey M, Rathnayake U (2022) A simplified mathematical formulation for water quality index (WQI): a case study in the Kelani River Basin. Sri Lanka Fluids 7:147. https://doi.org/10.3390/fluids7050147

Massoud MA (2012) Assessment of water quality along a recreational section of the Damour River in Lebanon using the water quality index. Environ Monit Assess 184:4151–4160. https://doi.org/10.1007/s10661-011-2251-z

Hamdi KM, Lihan S, Hamdan N, Tay MG (2022) Water quality assessment and the prevalence of antibiotic- resistant bacteria from a recreational river in Kuching, Sarawak, Malaysia. J Sustain Sci Manag 17:37–59. https://doi.org/10.46754/jssm.2022.05.004

Moskovchenko DV, Babushkin AG, Yurtaev AA (2020) The impact of the Russian oil industry on surface water quality (a case study of the Agan River catchment, West Siberia). Environ Earth Sci 79:1–21. https://doi.org/10.1007/s12665-020-09097-x

Mukate S, Wagh V, Panaskar D, Jacobs JA, Sawant A (2019) Development of new integrated water quality index (IWQI) model to evaluate the drinking suitability of water. Ecol Indic 101:348–354. https://doi.org/10.1016/j.ecolind.2019.01.034

Muniz DHF, Malaquias JV, Lima JE, Oliveira-Filho EC (2020) Proposal of an irrigation water quality index (IWQI) for regional use in the Federal District, Brazil. Environ Monit Assess 192:1–15. https://doi.org/10.1007/s10661-020-08573-y

Murillo-Delgado JO, Jimenez-Torres HD, Alvarez-Bobadilla JI, Gutierrez-Ortega JA, Camacho JB, Valle PFZ, Barcelo-Quintal ID, Delgado ER, Gomez-Salazar S (2021) Chemical speciation of selected toxic metals and multivariate statistical techniques used to assess water quality of tropical Mexican Lake Chapala. Environ Monit Assess 193:1–25. https://doi.org/10.1007/s10661-021-09185-w

Muvundja FA, Walumona JR, Dusabe MC, Alunga GL, Kankonda AB, Albrecht C, Eisenberg J, Wüest A (2022) The land–water–energy nexus of Ruzizi River Dams (Lake Kivu outflow, African Great Lakes Region): status, challenges, and perspectives. Front Environ Sci 10:892591. https://doi.org/10.3389/fenvs.2022.892591

Nair HC, Joseph A, Padmakumari Gopinathan V (2020) Hydrochemistry of tropical springs using multivariate statistical analysis in Ithikkara and Kallada river basins, Kerala, India. Sustain Water Resour Manag 6:1–21. https://doi.org/10.1007/s40899-020-00363-1

Najah A, Teo FY, Chow MF, Huang YF, Latif SD, Abdullah S, Ismail M, El-Shafie A (2021) Surface water quality status and prediction during movement control operation order under COVID-19 pandemic: case studies in Malaysia. Int J Environ Sci Te 18:1009–1018. https://doi.org/10.1007/s13762-021-03139-y

Nong X, Shao D, Zhong H, Liang J (2020) Evaluation of water quality in the South-to-North Water diversion project of China using the water quality index (WQI) method. Water Res 178:115781. https://doi.org/10.1016/j.watres.2020.115781

Ortega-Samaniego QM, Romero I, Paches M, Dominici A, Fraíz A (2021) Assessment of physicochemical and bacteriological parameters in the surface water of the Juan Diaz River, Panama. WIT Trans Ecol Environ 251:95–104. https://doi.org/10.2495/WS210101

Othman F, Alaaeldin ME, Seyam M, Ahmed AN, Teo FY, Fai CM, Afan HA, Sherif M, Sefelnasr A, El-Shafie A (2020) Efficient River water quality index prediction considering minimal number of inputs variables. Eng Appl Comp Fluid Mech 14:751–763. https://doi.org/10.1080/19942060.2020.1760942

Panneerselvam B, Muniraj K, Duraisamy K, Pande C, Karuppannan S, Thomas M (2022) An integrated approach to explore the suitability of nitrate-contaminated groundwater for drinking purposes in a semiarid region of India. Environ Geochem Hlth 10:1–7. https://doi.org/10.1007/s10653-022-01237-5

Parween S, Siddique NA, Mahammad Diganta MT, Olbert AI, Uddin MG (2022) Assessment of urban river water quality using modified NSF water quality index model at Siliguri city, West Bengal, India. Environ Sustain Indic 16:100202. https://doi.org/10.1016/j.indic.2022.100202

Paun I, Cruceru L, Chiriac FL, Niculescu M, Vasile GG, Marin NM (2016) Water quality indices—methods for evaluating the quality of drinking water. In: Proceedings of the 19th INCD ECOIND International Symposium—SIMI 2016, “The Environment and the Industry”, Bucharest, Romania, 13–14 October 2016: 395–402. https://doi.org/10.21698/simi.2016.0055

Peluso J (2021) Comprehensive assessment of water quality through different approaches: physicochemical and ecotoxicological parameters. Sci Total Environ 800:149510. https://doi.org/10.1016/j.scitotenv.2021.149510

Peng H (2022) Hydrochemical characteristics and health risk assessment of groundwater in karst areas of southwest China: a case study of Bama, Guangxi. J Clean Prod 341:130872. https://doi.org/10.1016/j.jclepro.2022.130872

Phadatare SS, Gawande S (2016) Review paper on development of water quality index. Int Res J Eng Technol 5:765–767. https://doi.org/10.17577/IJERTV5IS050993

Poonam T, Tanushree B, Sukalyan C (2013) Water quality indices- important tools for water quality assessment: a review. Int J Adv Chem 1:15–28. https://doi.org/10.5121/ijac.2015.1102

Qu X, Chen Y, Liu H, Xia W, Lu Y, Gang DD, Lin LS (2020) A holistic assessment of water quality condition and spatiotemporal patterns in impounded lakes along the eastern route of China’s South-to-North water diversion project. Water Res 185:116275. https://doi.org/10.1016/j.watres.2020.116275

Radeva K, Seymenov K (2021) Surface water pollution with nutrient components, trace metals and metalloidsin agricultural and mining-affected river catchments: a case study for three tributaries of the Maritsa River, Southern Bulgaria. Geogr Pannonica 25:214–225. https://doi.org/10.5937/gp25-30811

Ramírez-Morales D, Pérez-Villanueva ME, Chin-Pampillo JS, Aguilar-Mora P, Arias-Mora V, Masís-Mora M (2021) Pesticide occurrence and water quality assessment from an agriculturally influenced Latin-American tropical region. Chemosphere 262:127851. https://doi.org/10.1016/j.chemosphere.2020.127851

Ristanto D, Ambariyanto A, Yulianto B (2021) Water quality assessment based on national sanitations foundation water quality index during rainy season in Sibelis and Kemiri estuaries Tegal City. IOP Conf Ser: Earth and Environ Sci 750:012013. https://doi.org/10.1088/1755-1315/750/1/012013

Rizani S, Feka F, Fetoshi O, Durmishi B, Shala S, Çadraku H, Bytyçi P (2022) Application of water quality index for the assessment the water quality in River Lepenci. Ecol Eng Environ Tech 23:189–201. https://doi.org/10.12912/27197050/150297

Roozbahani MM, Boldaji MN (2013) Water quality assessment of Karoun river using WQI. Int Res J Appl Basic Sci 5:628–632

Roșca OM (2020) Impact of anthropogenic activities on water quality parameters of glacial lakes from Rodnei mountains, Romania. Environ Res 182:109136. https://doi.org/10.1016/j.envres.2020.109136

Rubio-Arias H, Contreras-Caraveo M, Quintana RM, Saucedo-Teran RA, Pinales-Munguia A (2012) An overall water quality index (WQI) for a man-made aquatic reservoir in Mexico. Int J Env Res Pub He 9:1687–1698. https://doi.org/10.3390/ijerph9051687

Said A, Stevens DK, Sehlke G (2004) An innovative index for evaluating water quality in streams. Environ Manage 34:406–414. https://doi.org/10.1007/s00267-004-0210-y

Samadi MT, Sadeghi S, Rahmani A, Saghi MH (2015) Survey of water quality in Moradbeik river basis on WQI index by GIS. Environ Eng Manag J 2:7–11

Sarwar S, Ahmmed I, Mustari S, Shaibur MR (2020) Use of Weighted Arithmetic Water Quality Index (WAWQI) to determine the suitability of groundwater of Chaugachcha and Manirampur Upazila, Jashore, Bangladesh. Environ Biolog Res 2:22–30

Scopus (2022) Analyze search results Retrieved February 22, 2023, from https://www.scopus.com/term/analyzer.uri?sid=8eeff2944308f3417393fe6b0de5b7e1&origin=resultslist&src=s&s=TITLE-ABS-KEY%28water+quality+index%29&sort=cp-f&sdt=b&sot=b&sl=34&count=38419&analyzeResults=Analyze+results&txGid=68cf75652b70f07c51075648639736f3

Shah KA, Joshi GS (2017) Evaluation of water quality index for River Sabarmati, Gujarat. India Appl Water Sci 7:1349–1358. https://doi.org/10.1007/s13201-015-0318-7

Shan W (2011) Discussion on parameter choice for managing water quality of the drinking water source. Procedia Environ Sci 11:1465–1468. https://doi.org/10.1016/j.proenv.2011.12.220

Singh PK, Tiwari AK, Panigary BP, Mahato K (2013) Water quality indices used for water resources vulnerability assessment using GIS technique: a review. Int J Earth Sci Eng 6:1594–1600

Sofi MS, Hamid A, Bhat SU, Rashid I, Kuniyal JC (2022) Impact evaluation of the run-of-river hydropower projects on the water quality dynamics of the Sindh River in the Northwestern Himalayas. Environ Monit Assess 194:626. https://doi.org/10.1007/s10661-022-10303-5

Steinhart CE, Shcierow LJ, Sonzogni WC (1982) Environmental quality index for the great lakes. Water Resour Bull 18:1025–1031

Stričević L, Pavlović M, Filipović I, Radivojević A, Martić Bursać N, Gocić M (2021) Statistical analysis of water quality parameters in the basin of the Nišava River (Serbia) in the period 2009–2018. Geografie 126:55–73. https://doi.org/10.37040/geografie2021126010055

Sudhakaran S, Mahadevan H, Arun V, Krishnakumar AP, Krishnan KA (2020) A multivariate statistical approach in assessing the quality of potable and irrigation water environs of the Netravati River basin (India). Groundw Sustain Dev 11:100462. https://doi.org/10.1016/j.gsd.2020.100462

Sukmawati NMH, Rusni NW (2019) Assessment of Water Quality Index of Beratan lake using NSF WQI indicator. Warmadewa Med J 4:39–43

Sutadian AD, Muttil N, Yilmaz AG, Perera BJC (2016) Development of river water quality indice- A review. Environ Monit Assess 188:58. https://doi.org/10.1007/s10661-015-5050-0

Taloor AK, Pir RA, Adimalla N, Ali S, Manhas DS, Roy S, Singh AK (2020) Spring water quality and discharge assessment in the Basantar watershed of Jammu Himalaya using geographic information system (GIS) and water quality Index (WQI). G Groundw Sustain Dev 10:100364. https://doi.org/10.1016/j.gsd.2020.100364

Tampo L, Alfa-Sika Mande SL, Adekanmbi AO, Boguido G, Akpataku KV, Ayah M, Tchakala I, Gnazou MDT, Bawa LM, Djaneye-Boundjou G, Alhassan EH (2022) Treated wastewater suitability for reuse in comparison to groundwater and surface water in a peri-urban area: Implications for water quality management. Sci Total Environ 815:152780. https://doi.org/10.1016/j.scitotenv.2021.152780

Teodorof L, Ene A, Burada A, Despina C, Seceleanu-Odor D, Trifanov C, Ibram O, Bratfanof E, Tudor MI, Tudor M, Cernisencu I, Georgescu LP, Iticescu C (2021) Integrated assessment of surface water quality in Danube River Chilia branch. Appl Sci 11:9172. https://doi.org/10.3390/app11199172

Tirkey P, Bhattacharya T, Chakraborty S (2015) Water quality indices-important tools for water quality assessment: a review. Int J Adv Chem 1:15–28

Tripathi M, Singal SK (2019) Allocation of weights using factor analysis for development of a novel water quality index. Ecotox Environ Safe 183:109510. https://doi.org/10.1016/j.ecoenv.2019.109510

Tyagi S, Sharma B, Singh P, Dobhal R (2013) Water quality assessment in terms of water quality index. Am J Water Resour 1:34–38. https://doi.org/10.12691/ajwr-1-3-3

Uddin MG, Nash S, Rahman A, Olbert AI (2022) A comprehensive method for improvement of water quality index (WQI) models for coastal water quality assessment. Water Res 219:118532. https://doi.org/10.1016/j.watres.2022.118532

Uddin MG, Nash S, Olbert AI (2021) A review of water quality index models and their use for assessing surface water quality. Ecol Indic 122:107218. https://doi.org/10.1016/j.ecolind.2020.107218

Udeshani WAC, Dissanayake HMKP, Gunatilake SK, Chandrajith R (2020) Assessment of groundwater quality using water quality index (WQI): a case study of a hard rock terrain in Sri Lanka. Groundw Sustain Dev 11:100421. https://doi.org/10.1016/j.gsd.2020.100421

Ugochukwu U, Onuora O, Onuarah A (2019) Water quality evaluation of Ekulu river using water quality index (WQI). J Environ Stud 4:4. https://doi.org/10.13188/2471-4879.1000027

Uning R, Suratman S, Bedurus EA, Nasir FAM, Hock Seng T, Latif MT, Mostapa R (2021) The water quality and nutrients status in the Dungun River Basin, Terengganu. Am Soc Microbiol Sci J 16:1–14. https://doi.org/10.32802/asmscj.2021.837

Vaiphei SP, Kurakalva RM (2021) Hydrochemical characteristics and nitrate health risk assessment of groundwater through seasonal variations from an intensive agricultural region of upper Krishna River basin, Telangana. India. Ecotox Environ Safe 213:112073. https://doi.org/10.1016/j.ecoenv.2021.112073

Valentini M, dos Santos GB, Muller Vieira B (2021) Multiple linear regression analysis (MLR) applied for modeling a new WQI equation for monitoring the water quality of Mirim Lagoon, in the state of Rio Grande do Sul—Brazil. SN Appl Sci 3:70. https://doi.org/10.1007/s42452-020-04005-1

Varol S, Davraz A, Şener Ş, Şener E, Aksever F, Kırkan B, Tokgözlü A (2021) Assessment of groundwater quality and usability of Salda Lake Basin (Burdur/Turkey) and health risk related to arsenic pollution. J Environ Health Sci 19:681–706. https://doi.org/10.1007/s40201-021-00638-5

Vasistha P (2020) Assessment of spatio-temporal variations in lake water body using indexing method. Environ Sci Pollut R 27:41856–41875

Wang Q, Li Z, Xu Y, Li R, Zhang M (2022) Analysis of spatio-temporal variations of river water quality and construction of a novel cost-effective assessment model: a case study in Hong Kong. Environ Sci Pollut R 29:28241–28255. https://doi.org/10.1007/s11356-021-17885-6

Wong YJ, Shimizu Y, He K, Nik Sulaiman NM (2020) Comparison among different ASEAN water quality indices for the assessment of the spatial variation of surface water quality in the Selangor River basin. Malaysia Environ Monit Assess 192:644. https://doi.org/10.1007/s10661-020-08543-4

Xiao L, Zhang Q, Niu C, Wang H (2020) Spatiotemporal patterns in river water quality and pollution source apportionment in the Arid Beichuan River Basin of Northwestern China using positive matrix factorization receptor modeling techniques. Int J Env Res Pub He 17:5015. https://doi.org/10.3390/ijerph17145015

Xiong F, Chen Y, Zhang S, Xu Y, Lu Y, Qu X, Gao W, Wu X, Xin W, Gang DD, Lin LS (2022) Land use, hydrology, and climate influence water quality of China’s largest river. J Environ Manage 318:115581. https://doi.org/10.1016/j.jenvman.2022.115581

Yan F, Liu L, You Z, Zhang Y, Chen M, Xing X (2015) A dynamic water quality index model based on functional data analysis. Ecol Indic 57:249–258. https://doi.org/10.1016/j.ecolind.2015.05.005

Yang Z, Bai J, Zhang W (2021) Mapping and assessment of wetland conditions by using remote sensing images and POI data. Ecol Indic 127:107485. https://doi.org/10.1016/j.ecolind.2021.107485

Yılmaz E, Koç C, Gerasimov I (2020) A study on the evaluation of the water quality status for the Büyük Menderes River, Turkey. Sustain Water Resour Manag 6:100. https://doi.org/10.1007/s40899-020-00456-x

Yogendra K, Puttaiah ET (2008) Determination of water quality index and suitability of an urban waterbody in Shimoga Town, Karnataka. Proceedings of Taal 2007: The 12th world lake conference 342: 346

Yotova G, Varbanov M, Tcherkezova E, Tsakovski S (2021) Water quality assessment of a river catchment by the composite water quality index and self-organizing maps. Ecol Indic 120:106872. https://doi.org/10.1016/j.ecolind.2020.106872

Yuan H, Yang S, Wang B (2022) Hydrochemistry characteristics of groundwater with the influence of spatial variability and water flow in Hetao Irrigation District, China. Environ Sci Pollut R 20:1–5. https://doi.org/10.1007/s11356-022-20685-1

Zakir HM, Sharmin S, Akter A, Rahman MS (2020) Assessment of health risk of heavy metals and water quality indices for irrigation and drinking suitability of waters: a case study of Jamalpur Sadar area, Bangladesh. Environ Adv 2:100005. https://doi.org/10.1016/j.envadv.2020.100005

Zhan S, Zhou B, Li Z, Li Z, Zhang P (2021) Evaluation of source water quality and the influencing factors: a case study of Macao. Phys Chem Earth Parts a/b/c 123:103006. https://doi.org/10.1016/j.pce.2021.103006

Zhang L (2017) Different methods for the evaluation of surface water quality: the case of the Liao River, Liaoning Province, China. Int Rev Spat Plan Sustain Dev 5:4–18. https://doi.org/10.14246/irspsd.5.4_4

Zhang L (2019) Big data, knowledge mapping for sustainable development: a water quality index case study. Emerg Sci J 3:249–254. https://doi.org/10.28991/esj-2019-01187

Zhang ZM, Zhang F, Du JL, Chen DC (2022) Surface water quality assessment and contamination source identification using multivariate statistical techniques: a case study of the Nanxi River in the Taihu Watershed, China. Water 14:778. https://doi.org/10.3390/w14050778

Zhu X, Wang L, Zhang X, He M, Wang D, Ren Y, Yao H, Net Victoria Ngegla J, Pan H (2022) Effects of different types of anthropogenic disturbances and natural wetlands on water quality and microbial communities in a typical black-odor river. Ecol Indic 136:108613. https://doi.org/10.1016/j.ecolind.2022.108613

Zotou I, Tsihrintzis VA, Gikas GD (2018) Comparative assessment of various water quality indices (WQIs) in Polyphytos reservoir-Aliakmon River. Greece Proc 2:611. https://doi.org/10.3390/proceedings2110611

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Chidiac, S., El Najjar, P., Ouaini, N. et al. A comprehensive review of water quality indices (WQIs): history, models, attempts and perspectives. Rev Environ Sci Biotechnol 22 , 349–395 (2023). https://doi.org/10.1007/s11157-023-09650-7

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Received : 07 December 2022

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Published : 11 March 2023

Issue Date : June 2023

DOI : https://doi.org/10.1007/s11157-023-09650-7

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Topics of Focus

In the United States alone, billions of gallons of water are treated each day at water resource recovery facilities. Once the water is clean, a different challenge remains: determining what to do with the solids that are removed during the treatment process. The resulting mixture is often a unique semi-solid blend of organic and inorganic materials, trace elements, chemicals, and even pathogens, so there is no across the board solution for handling and processing the combinations of constituents that may be present.

Because these solids are often rich in nutrients, like nitrogen and phosphorus—which also happen to be the perfect ingredients for promoting healthy soil and plant growth—many facilities have turned to land application. Before these solids can be put to use for things like fertilizing farmland, however, they must undergo rigorous treatment to meet stringent regulations, at which point they become known as biosolids.

Characterization and Contamination Testing of Source Separated Organic Feedstocks and Slurries for Co-Digestion at Resource Recovery Facilities

Project highlights.

A key challenge with source separated organic (SSO) feedstock co-substrate is that its composition, quality, and characteristics differ between geographical locations and can change over time. This causes challenges and uncertainties for pre-treaters, substrate brokers, facilities accepting this material, operators...

The Water Research Foundation Funds 26 New Research Projects Totaling $5.9M

(Denver, CO) 05/28/24– The Water Research Foundation (WRF) is seeking volunteer participants for 26 new research projects funded through WRF's Research Priority Program. This strategic research program enables WRF to...

Interview with Dr. William Tarpeh

Turning Waste into Gold with Dr. William Tarpeh A rare few people end up in the career they decided for themselves as children. More often, the question “What do you...

WRF Presents $100K Research Award To Advance Wastewater Resource Recovery

(Denver, CO) 10/11/23 – Last week, The Water Research Foundation (WRF) presented William Tarpeh, PhD, with the esteemed 2023 Paul L. Busch Award. With this $100,000 research prize, Dr. Tarpeh...

Climate Change

Climate change is altering our natural hydrologic cycle, creating uncertainty when it comes to the quality and quantity of water sources. WRF’s research on climate change covers the key areas of climate risk assessment, climate adaptation, and mitigation strategies.

Because the first step in preparing for climate change is understanding the potential and variable impacts these changes can have on water sources and treatment systems, WRF research tracks potential outcomes, considering a variety of possibilities, and provides resources and tools to help facilities identify and address risks and vulnerabilities in their operations and infrastructure.

Implementing climate change adaptation strategies will be critical as the water sector moves forward. WRF’s research in this area helps utilities create better long- and short-term adaptation plans, respond more effectively to severe weather, and improve infrastructure and operations to meet changing needs, including the production of onsite energy systems and reliable back-up power to protect critical services.

The water sector must also have a hand in mitigating the root causes of climate change. By pioneering approaches to improve energy efficiency, including process optimization, improved energy management, and the use of renewable energy, WRF is helping the water sector decrease activity that is driving these changes.

For more information, contact Harry Zhang .

Holistic Approaches to Flood Mitigation Planning and Modeling under Extreme Events and Climate Impacts

Municipalities and utilities are facing unprecedented challenges in planning for extreme precipitation and flooding events, which are occurring more frequently and unpredictably. A holistic approach to flood mitigation planning and modeling, including partnerships between stakeholders, is needed to balance competing...

One Water Cities: A Self-Assessment Framework

Municipalities play key roles in implementing One Water approaches and furthering community resilience. Read the full article.

The Water Research Foundation Honors Outstanding Water Leaders

(Denver, CO) 6/21/23 - The Water Research Foundation (WRF) announced last week that it awarded its 2023 Subscriber Impact Award to Denver Water and its 2023 Research Innovation Award to...

Cyanobacteria & Cyanotoxins

Aquatic microscopic algae and cyanobacteria (formerly known as blue-green algae) occur naturally in most surface waters. However certain nutrient and temperature conditions can cause them to multiply rapidly, leading to “blooms.” Under certain conditions, some species of cyanobacteria can produce toxic secondary metabolites or cyanotoxins, which may pose health risks to humans and animals. Even when cyanobacteria are not toxic, they can produce unpleasant tastes and odors.

Cyanobacteria continue to be among the most problematic organisms in fresh water systems. Without clear guidance or consensus regulations in place, many utilities struggle with responding to cyanobacterial harmful algal bloom (cHAB) events. Since 1994, WRF has completed more than 40 research projects on these microscopic organisms and the cyanotoxins they produce, helping facilities detect, monitor, and manage these organisms—as well as communicate with the public.

For more information, contact Sydney Samples .

Refinement and Standardization of Cyanotoxin Analytical Techniques for Drinking Water

There is uncertainty relating to the screening and confirmation of cyanotoxin samples. Water utilities need robust and dependable methods to monitor cyanotoxins in source water, through the treatment process, and at the tap, as well as to make appropriate decisions...

The Water Research Foundation Funds Utility Research Projects Worth $5M in Research Value

(Denver, CO) 12/19/2023 – The Water Research Foundation (WRF) has selected twelve new projects for funding through its Tailored Collaboration Program, totaling over $5 million in research value. The projects...

PFAS Communication Guidance

Water sector professionals need to be able to communicate with their customers clearly, concisely, and consistently about per- and polyfluoroalkyl substances (PFAS). This may include information on what PFAS are...

Per- and Polyfluoroalkyl Substances

Per- and polyfluoroalkyl substances (PFAS) are man-made compounds with fluorinated carbon chains. They are resistant to heat, oil, and water, making them useful in a wide variety of products, including...

Disinfection Byproducts (DBPs)

The use of strong oxidants to disinfect water has virtually eliminated waterborne diseases like typhoid, cholera, and dysentery in developed countries. However, research has shown that chlorine interacts with natural organic matter present in water supplies to form regulated and emerging disinfection byproducts (DBPs).

To minimize the formation of regulated DBPs and comply with existing regulations, water utilities have increasingly been moving away from chlorine to use alternative disinfectants like chloramine, or installing more advanced and costly treatment processes, such as ozone or granular activated carbon to remove DBP precursors. However, while reducing the formation of halogenated DBPs, alternative oxidants have been shown to favor the formation of other DBPs (e.g., ozone producing bromate and halonitromethanes, and chloramines producing N-nitrosodimethylamine and iodinated DBPs). 

For more information, contact Kenan Ozekin .

Impact of Haloacetic Acid MCL Revisions on DBP Exposure and Health Risk Reduction

The U.S. Environmental Protection Agency (EPA) is considering changes to the disinfectant and disinfection byproducts (D/DBP) rule. Specifically, there may be a shift from the currently regulated five haloacetic acids (HAA5) to nine (HAA9), which would include four additional brominated...

WRF Seeks Pre-proposals for High-Priority Utility Research

(Denver, CO) 02/15/24 – The Water Research Foundation (WRF) is now accepting pre-proposals for its matching research program, the Tailored Collaboration Program. The Tailored Collaboration Program provides an opportunity for...

The Water Research Foundation Seeks Nominations for Paul L. Busch Award

(Denver, CO) 02/08/24 – The Water Research Foundation (WRF) is now accepting nominations for the 2024 Paul L. Busch Award. The $100,000 award recognizes one outstanding individual for innovative research...

Energy Optimization

For most water facilities, energy is one of the highest costs in their operating budget. Stricter regulations are pushing facilities to use even more advanced—and energy-intensive—treatment technologies. Optimizing energy use can provide huge cost savings and numerous additional benefits, including improving air quality, protecting the environment, and bolstering energy security. WRF has published more than 100 projects that explore ways to not only optimize current energy use, but to generate power as well—setting the course for a self-sufficient water sector.

Developing a Framework for Quantifying Energy Optimization Reporting

Energy projects within the water sector are often discretionary and initiated based on projected annual energy savings metrics. The water sector lacks standard energy savings estimation procedures, as well as measurement and verification approaches and procedures that adhere to the...

Intelligent Water Systems

As with other industries, newly developed technologies drive water utilities to adapt their day-to-day operations. Water networks have been a special focus, with new instrumentation options for water production, transmission, distribution, wastewater collection, and consumer end-points coming to market. Implementing these technologies can improve the efficiency and reliability of water networks, but with myriad options, utilities need guidance on which technologies are most worthwhile and how they should be implemented. 

Quantifying the Impact of Artificial Intelligence/Machine Learning-Based Approaches to Utility Performance

The purpose of this project is to survey the water industry and identify the use cases for artificial intelligence (AI) and machine learning (ML), quantify their benefits, and provide a framework for others to be able to make the same...

2024 Intelligent Water Systems Challenge

The Leaders Innovation Forum for Technology (LIFT) program, a joint effort of The Water Research Foundation (WRF) and the Water Environment Federation (WEF), is holding the sixth Intelligent Water Systems...

WRF Seeks Proposals for 22 New Research Projects Totaling $4.9M

(Denver, CO) 9/12/23 - The Water Research Foundation (WRF) is now accepting proposals for 22 research projects totaling $4.9M that will advance the science of water for communities around the...

The Water Research Foundation and Water Environment Federation Launch the Fifth Intelligent Water Systems Challenge

(Denver, CO) 02/6/23 – The Water Research Foundation and Water Environment Federation are pleased to invite teams to participate in the fifth annual Intelligent Water Systems (IWS) Challenge. As technology...

Microbes & Pathogens

Control of microbes in water systems is critical to achieving water quality and public health goals. While most microbes are not considered human pathogens, certain microbes can pose health risks or contribute undesirable tastes and odors. 

Since the early 20th century, modern drinking water treatment has made great advancements in the detection, removal, and inactivation of bacteria, viruses, and protozoa. As technologies in the drinking water space continue to progress, new challenges have arisen in the form of opportunistic premise plumbing pathogens. 

Wastewater and stormwater utilities also play an essential role in reducing the pathogen load to receiving waters used for recreation.  Additionally, more recent advancements in water reuse, especially direct potable reuse, demand more understanding of pathogen detection, removal, and inactivation in wastewater. 

For more information, contact Grace Jang (drinking water & reuse) or Lola Olabode (wastewater).

Demonstrating the Effectiveness of Flushing for Reducing the Levels of Legionella in Service Lines and Premise Plumbing

Legionella are pervasive environmental bacteria that can incidentally cause severe and sometimes fatal infections upon inhalation. Because Legionella inhabit engineered environments and proliferate in warm, stagnant premise water systems, the majority of outbreaks are associated with preventable water system maintenance...

Interview with Cheryl Norton

Cheryl Norton’s Lasting Journey with WRF and the Water Sector From leading a Water Research Foundation (WRF)- funded project right out of college, to becoming an integral member of the...

Resource Recovery

In recent decades, the wastewater sector has moved away from the idea of wastewater treatment plants as waste disposal facilities, instead envisioning these plants as water resource recovery facilities (WRRFs). WRRFs can produce clean water, recover nutrients (such as phosphorus and nitrogen), and potentially reduce fossil fuel consumption through the production and use of renewable energy.

For more information, contact Jeff Moeller .

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Transforming aeration energy in water resource recovery facilities (wrrfs) through suboxic nitrogen removal, advances in water research.

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Water quality monitoring is a crucial aspect to protecting water resources. Under the Clean Water Act, state, tribal and federal agencies monitor lakes, streams, rivers and other types of water bodies to determine water quality condition. The data generated from these monitoring activities help water resource managers know where pollution problems exist, where to focus pollution control energies and where progress has been made.

• The Water Quality Exchange (WQX) is the mechanism for data partners to submit water monitoring data to EPA.
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The Water Quality Portal is the nation's largest source for water quality monitoring data. The Water Quality Portal (WQP) uses the  Water Quality Exchange (WQX) data format to share over 380 million water quality data records from 900 federal, state, tribal and other partners.

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Water is life. It is that simple.

Water from terrestrial, coastal and marine sources is essential for human health, well-being and livelihoods, ecosystem functioning and services, and the survival of all living species.  

Waste and pollution, climate change and severe pathogen contamination present severe challenges to both the quantity and quality of water, in turn exacerbated by human activities such as urbanisation, industrial and agricultural activity and a lack of basic sanitation. It is the poor, the vulnerable, women and children who are at most risk to the effects of water quality degradation and who bear the brunt of these consequences.

To overcome these concerns, UNEP/EA.3/Res.10 outlined an urgency to eradicate the gaps in our knowledge of the state of water quality resulting from a lack of data and regular monitoring, and invited UNEP to develop a global assessment of water quality. 

What is the World Water Quality Assessment?  There exists an urgency to eradicate the gaps in society’s knowledge of the state of water quality resulting from a lack of data and regular monitoring. The purpose of the Pathway to the World Water Quality Alliance is to eliminate the gaps and establish a point of reference for all those who require information regarding water quality.

The United Nations Environment Assembly (UNEA) of the United Nations Environment Programme (UNEP), in its third session held in Nairobi in 2017, adopted UNEP/EA.3/Res.10 on “Addressing water pollution to protect and restore water-related ecosystems”. The resolution recognizes that water from terrestrial, coastal and marine sources is essential for human health, well-being and livelihoods, ecosystem functioning and services, and the survival of all living species. It established a number of vital premises which constitute the foundation for the creation of a pathway towards a World Water Quality Assessment. 

The Assessment pathways

Learn about specific water quality-related issues, click on a pathway, read the introduction to the issue, and access more related articles.

Human health

Water impacts human health in various ways, which are usually determined by how we come into contact with it. 

Find out more

Water impacts human health in various ways, which are usually determined by how we come into contact with it. On a typical day, those of us lucky enough to live outside areas of water scarcity, drink water, bathe in it, cook with it, and eat food raised in it. All of these contacts are pathways for exposure to pathogens and contaminants that have the potential for adverse impacts on our well-being.

• Modelling has been a prominent approach to derive estimates on human health impacts from contaminated water, the water quality state, and the contamination sources. 
• First estimates of human-health impacts originating from the pathogen Cryptosporidium (single-cell parasite) shows hotspots in areas where surface water is still regularly used for direct drinking in Asia. This is true also for arsenic hotspots. For most other contaminants no impact studies are available at large scale.
• Concentration hotspots are, for most contaminants, densely populated areas where wastewater treatment is limited. For groundwater arsenic and surface-water salinity concentrations, hotspots include India, China and Mongolia.

Water, water everywhere, but is it good enough to drink?

Water quality has been linked to human health ever since a cholera outbreak in 1855 was attributed to contaminated water. Even today water is said to play a big role in the millions of cholera cases around the world each year. More recently, concerns were raised after the virus responsible for COVID-19 was found in wastewater at a number of locations. Though so far no evidence has been found for the presence of viable or infectious virus particles in these wastewater samples, the question of what viruses in wastewater can tell us has been included in a European Union monitoring study.

The toxic compound arsenic is widely present in groundwater and can lead to skin, vascular and nervous system disorders and cancer. Recent estimates show that 94-220 million people are exposed to high arsenic concentrations in groundwater. Similarly, fluoride, nitrate, heavy metals, and salinity pose human health risks.

Contact pathways

People are exposed to water in many different ways, depending on their location, livelihood, culture, wealth, and gender. The most common exposure pathways can be summarized as drinking, bathing, ingestion during domestic use, eating irrigated vegetables, rice (or rice products) or aquatic plants (such as water spinach), eating contaminated fish and shellfish, and skin contact. These pathways highlight that the quality of ground, surface and coastal waters is relevant to human health. 

An unknown burden

But evaluations of impaired water quality on human health are not yet widely available, and were only available at large scale for pathogens, arsenic and salinity. For Cryptosporidium, which can cause respiratory and gastrointestinal illness in humans, modelling was used to evaluate the disease burden. Preliminary results showed people drinking surface water directly have the highest disease burden. This was particularly true in Africa and Papua New Guinea, which have large share of their populations drinking surface water directly. Globally, rural populations directly drinking surface water contaminated with faecal coliforms decreased between 2008 and 2017, but at different rates across Latin America, Africa and Asia. Further analysis is needed to achieve a complete evaluation, including for other pathogens and other exposure pathways.

Ecosystem health

Nutrient run-off from fertilizers used in food production for the world’s growing population, along with toxic stress from chemicals used in pharmaceuticals......

Nutrient run-off from fertilizers used in food production for the world’s growing population, along with toxic stress from chemicals used in pharmaceuticals, pesticides and veterinary drugs, are polluting water bodies contributing to harmful algal blooms and damaging aquatic ecosystems. 

• In 2020, anthropogenic sources contribute more than 70 per cent to river nutrient loading.
• Most of the increase of river nutrient loading has been in Asia.
• Harmful algae blooms are now spreading in many river basins.
• Curbing global nutrient cycles requires paradigm shifts in food and waste systems.
• Two large-scale European assessments on ca. 2,000 chemicals report chronic effects of (a mixture of) chemicals on aquatic species to be expected at 42-85 percent of the studied sites, while 14-43 per cent of the sites are likely to experience some degree of species loss. 
• Assessments such as those done for Europe cannot be made on a global scale. Neither the measured data or the information to generate predicted concentrations are available yet. 
• The Human Impact and Water Availability Indicator (HIWAI) can be used to extrapolate results obtained for Europe. This proxy was found to correlate well with the expected loss of aquatic species in European surface waters. 

More people, more pollution

The world’s growing population, and the need to keep people fed and healthy, are contributing to two kinds of pollution that have a major impact on the health of the planet’s ecosystems: nutrient pollution and toxic stress by chemicals.

Nutrient pollution occurs when fertilizers, primarily nitrogen and phosphorus, used in food production or coming from untreated wastewater, enter soils, groundwater and surface water and are transported towards coastal seas. This can cause a number of problems, including groundwater pollution, loss of habitat and biodiversity, creation of coastal dead zones, harmful algal blooms, fish kills and human health impacts.

Harmful algae blooms may render water unsuitable for drinking, irrigation, bathing or swimming. Also, increased growth of algae may deplete oxygen, killing aquatic organisms. This may lead to bad odours that affect local tourism, and to massive fish kills that affect local fisheries. These algal blooms are becoming more and more common in world waters.  

The importance of agriculture

In the Earth’s system, nutrient cycles have intensified dramatically in the past 50 years, with global nitrogen up 75 per cent and phosphorus up 92 per cent between 1970 and 2020. At the same time, the world’s population increased by three billion people. As a result, protein and phosphorus consumption and excretion also increased significantly, which reflects a growing number of people eating more meat and dairy products. However, nutrient flows related to food consumption are minor when compared to those from food production. Agriculture is now the most important source.

Aquatic life at risk

Around the world, about 40 per cent of the total population is connected to a sewage system, with wastewater treatment plants removing 26 per cent of the emissions from connected households. The remaining nitrogen and phosphorus in the untreated wastewater, plus effluents after treatment, contribute 15-17 per cent to total nutrient flows to water bodies.

Lake eutrophication, where nutrient pollution has caused an overgrowth of plants that depletes oxygen, poses a survival risk to aquatic organisms, affecting fisheries and aquaculture. Alarmingly, eutrophication is a worldwide phenomenon, with rapidly declining aquatic biodiversity.  

A heavy load

Toxic stress from chemicals is when some of the more than 350,000 chemicals registered for use, or combinations of them, accumulate in rivers, lakes and seas, damaging aquatic life. Typically, these chemicals are used in agriculture, for food production, or in pharmaceutical products to keep us in good health.

In general, increasing economic development leads to an increasing use of a wide range of chemicals. 

Global chemical sales (excluding pharmaceuticals) are projected to grow from €3.47 trillion in 2017 to €6.6 trillion by 2030, with Asia expected to account for almost 70 percent of sales by then.

Food security

Food security and safety cannot be achieved without tackling the issues that affect water quality. Water plays a key role in food production through crop irrigation, which increases crop yields.

Food security and safety cannot be achieved without tackling the issues that affect water quality. Water plays a key role in food production through crop irrigation, which increases crop yields. But salinity, pollution, and other contaminants all pose risks that could reduce the amount of food available to safely feed the world’s growing population. 

• First estimates of water-quality impacts on food security show hotspots in north-eastern China, India, the Middle East, parts of South America, Africa, Mexico, the United States and the Mediterranean. 
• Estimates reveal that more than 200,000 km² of agricultural land in South Asia may be irrigated with saline water exceeding the Food and Agriculture Organization guideline of 450 mg/l, and more than 154,000 km² show a high probability of groundwater arsenic concentrations that exceed the World Health Organization guideline of 10 µg/l.
• Aquaculture and mariculture (marine farming) production are important to produce high-quality protein, but both can be at risk because of water pollution, such as increased nutrient concentrations.
• Wastewater reuse in irrigation is an option to overcome water shortages and to close the nutrient cycle, but the food produced may become contaminated by pathogens (and faecal coliform bacteria), antimicrobial resistant microorganisms, and chemicals if wastewater has not been treated sufficiently.

We are more and more dependent on irrigation for the food we eat, but the impact of water quality on food products and industries is often underestimated.

Population growth, increasing incomes and dietary changes have meant a need for greater food production, and, globally, an estimated two billion people do not have regular access to safe and sufficient food. Water plays a central role in food production, as crop yields are higher from irrigated land. Some 40 per cent of crop production worldwide is harvested from irrigated land, which can be cultivated more than once a year under favourable water and climate conditions. Globally, about 70 per cent of abstracted water is used in agriculture.

Risk factors

One of the biggest risks from irrigation is an increase in salt in the soil, which can reduce crop yields. About 34 million hectares, or 11 per cent of global irrigated land, are affected by salinization, 77 per cent of which is in Asia, particularly in Pakistan, China and India.

Another risk is arsenic, which can accumulate in topsoil. It also bioaccumulates in vegetables, rice and other crops, which poses a risk for food-chain contamination and human health. Arsenic is present in trace amounts throughout the Earth’s crust and may leach into groundwater. If that groundwater is then used for irrigation, food safety may be compromised. In South Asia, more than 154,000 km² of agricultural land may be irrigated with water that exceeds the World Health Organization guideline for arsenic.

Fish and shellfish produced by aquaculture in cages both contribute to water-quality deterioration and are at risk from it. Nutrient pollution – nitrogen and phosphorus run-off from fertiliser use or untreated wastewater – can contribute to harmful algal blooms in aquaculture ponds.

Other pollutants, including microplastics and Triclosan, an antibacterial and antifungal chemical used in hygiene products, flow to rivers and seas from sewage systems and poorly handled solid waste.  These could enter the food chain and have an impact on human health. River basins with high Triclosan and microplastics inputs are mainly located in Europe, India, China and some individual sub-basins in South and North America.

What it all means

Food safety is affected by the quality of water used in irrigation, and also by that along the entire supply chain from food production to consumption. Water used in each step of the supply chain can be a source of exposure to various contaminants, such as pathogens, heavy metals, persistent organic pollutants, Triclosan and microplastics.

Food security and safety cannot be achieved without tackling water issues, since lack of safe water worsens food insecurity. Polluted irrigation water damages health and nutrition and reduces food production, constraining agricultural and economic development, especially in densely populated regions where water is already scarce and wastewater treatment is poor.

It is difficult to quantify the impact of water quality on food security because the necessary data are often lacking. Data derived from water-quality modelling in combination with remote sensing can close data gaps, identify hotspots, and map pollutant intakes.

Climate change

Of the planet’s 117 million lakes, only a tiny fraction (0.0001 per cent) can be monitored regularly or systematically on the ground.

Of the planet’s 117 million lakes, only a tiny fraction (0.0001 per cent) can be monitored regularly or systematically on the ground. Images captured from satellites orbiting the Earth have magnificent potential to transform our ability to monitor inland waters. 

Key messages

•  The increasing availability of free-to-access satellite data can radically transform how we assess and monitor inland waters.    
• Space agencies and stakeholders must work together to co-develop the next generation of ‘better, cheaper and faster’ satellite-based water services.

Why inland waters?

Inland water bodies, such as lakes, reservoirs and rivers, are extremely important to human societies. These waters play a crucial role in human health and well-being, supplying water for drinking (humans and animals) and food (irrigation, fisheries and aquaculture). They create vital ecosystems, supporting high levels of biodiversity and contributing to the global carbon and nutrient cycles. Moreover, lakes and reservoirs store information from the entire basin and so act as records of environmental change.

Despite their importance, many inland water bodies are under severe pressure, including from pollution, invasive species, extraction of upstream water, and climate change. As they connect three-quarters of the Earth’s terrestrial surface with the oceans, the study of inland waters is key to monitor the impact of such pressures. 

Lakes are of crucial importance for food security, the provision of clean water for drinking and irrigation, energy production, navigation, recreation and biodiversity. 

Lakes are of crucial importance for food security, the provision of clean water for drinking and irrigation, energy production, navigation, recreation and biodiversity. Yet they are coming under increasing pressure, affecting water quality and causing biodiversity loss.

Water quality and lakes

Lakes come in many shapes and sizes, from small urban ponds, through constructed reservoirs, to the largest transboundary lakes. Collectively, these ecosystems are critical in supporting many societal needs. These include the provision of food and clean water, navigation, achieving Net Zero Carbon climate ambitions and renewable energy production, reversing biodiversity loss, delivering national and international food and non-food trade objectives, supporting livelihoods and creating jobs. 

The current environmental status of lakes is one of large-scale degradation, threatening their societal and economic value and incurring significant loss and damage. One of the main pressures globally is nutrient pollution from agriculture and wastewater, although effects of climate change, plastic pollution, hydrological alteration, industrial waste discharges, invasive species infestations, and habitat destruction are also prevalent.

‘ Undervalued, understudied, and overlooked’

The current global approach to lake management is inadequate. Local to global management responses remain fragmented, under-resourced and undervalued. If left unchecked, societal impacts are predicted to substantially worsen in the coming decades. Global analyses project that by 2050 these impacts will include a decrease in the value of ecosystem services (currently estimated at $US3 trillion) by up to 20 per cent; a doubling (at least) of nutrient pollution from agriculture and wastewater, costing hundreds of billions of dollars a year to address; increased methane emissions from lakes with global societal costs estimated in the trillions of dollars; and a further increase in the rate of biodiversity loss from freshwater ecosystems, which is already higher than in any other biome. 

Lakes and reservoir ecosystems are undervalued, understudied, and often overlooked. Yet, they are of crucial importance for food security, the provision of clean water for drinking and irrigation, energy production, navigation, recreation and biodiversity. The global value of freshwater ecosystem services is in the order of trillions of dollars. 1 The importance of exposure to nature in managing mental health and improving well-being is also becoming increasingly apparent. For example, access to ‘blue-green spaces’, including lakes, reduced mental health impacts of severe lockdown during the COVID-19 pandemic. 2  

1 Costanza et al , (2014). 

2 Pouso et al , (2021). 

Three locations in Africa were chosen as test sites for water-quality data collection and investigation of the relationship between water quality and local development to deliver on Agenda 2030. 

Three locations in Africa were chosen as test sites for water-quality data collection and investigation of the relationship between water quality and local development to deliver on Agenda 2030. The objective was to link water-quality hotspots to solutions and investment priorities. 

• Cape Town’s groundwater is vulnerable to water-quality impacts from urban development in an area with various land-use activities, posing a risk to the planned potable water supply. As a results, aquifer protection zones were co-designed. 
• Key water-quality challenges at Lake Victoria were identified as eutrophication; algal blooms (including cyanobacteria); hypoxia, and siltation/turbidity affecting fish breeding. Water quality data and information products and services being co-developed are a coastal eutrophication assessment, water temperature and stratification dynamics, and sediment chemistry.  
• The Volta Basin water-quality impacts were identified as domestic and industrial effluent, mining impacts, agricultural runoff, and aquaculture; expected to be exacerbated in the future by climate change, population increase, urbanization, and land-use change. Water quality product options being explored are a tool to determine the percentage of populations vulnerable to poor water quality, and a remote sensing-based groundwater quality assessment.

Water-quality Africa Use Cases

Three locations in Africa were selected for Use Case studies focused on urban groundwater (Cape Town), a lake of ecological and economic importance (Lake Victoria and associated basin), and a watercourse with pathogen risks (Volta River). The goal was to identify priority water-quality issues and hotspots and to co-design, pilot and demonstrate innovative information services and their application for water-quality improvement with the potential for upscaling and operational use. In the mid- to long-term, the World Water Quality Alliance hopes to build on experience here to provide further services to improve water quality, engage with UN Country Teams, and enable upscaling to other locations. 

The Atlantis, Cape Flats and Table Mountain Group aquifers were all targeted by the City of Cape Town as a potential potable water supply. The Cape Flats and Atlantis aquifers were vulnerable to pollution from urban settlements, resulting in salinization and anthropogenic contamination with nutrients, microbiological and industrial contaminants, hydrocarbons and other contaminants. The Table Mountain Group aquifer, on the other hand, was in relatively pristine areas with good water quality, but had naturally occurring elevated concentrations of iron and manganese. 

Extensive monitoring data was collected and presented to a meeting of stakeholders, and, as a result, the City of Cape Town and agricultural users of the aquifer suggested that a plan be co- developed to protect water quality. The scheme sets up groundwater protection zones around abstraction boreholes, identifies and maps contamination activities, and restricts them where the risk is high.

Lake Victoria Basin

Africa’s largest lake, Lake Victoria, is split between three countries, Kenya, Uganda and Tanzania. Working with stakeholders from the three countries, the central aims of the Use Case were to collectively assess water-quality challenges and associated impacts at Lake Victoria and its catchment, develop a stakeholder network, and assess data sources and types associated with the lake, and any limitations to the sharing of such data.

Key challenges identified included eutrophication, algal blooms, hypoxia and turbidity. Water quality data and information products and services being co-developed are a coastal eutrophication assessment, water temperature and stratification dynamics, and sediment chemistry. 

Volta Basin

A Stakeholder Engagement Workshop was held in Accra, Ghana, to assess the water-quality hotspots and to initiate a bottom-up social engagement process. 

The key challenges identified were poor sanitation resulting in elevated bacterial contamination, mining activities, industrial effluent (including plastics and microplastics), agricultural runoff of fertilizers and pesticides, and water-quality impacts to and from aquaculture. A further challenge is there is not a consolidated national government department mandated to do water quality monitoring, with this role currently split.

Discussions about potential in-country partnerships and water-quality product and services are continuing, but these may include a tool that translates poor water quality into estimates of impacts on affected populations, and a mapping and assessment of groundwater quality. 

Information derived from monitoring and assessing freshwater quality serves as an early warning system on future climate change impacts. 

Information derived from monitoring and assessing freshwater quality serves as an early warning system on future climate change impacts. These are related to biodiversity and ecosystem loss, human health and livelihood impacts, food security and pollution mitigation. Understanding water quality trends in rivers, lakes and aquifers presents a significant challenge that many countries are unable to meet. Facing and addressing this challenge presents an opportunity that could help build climate change resilience on multiple fronts. This is especially relevant in those countries that are predicted to be most impacted by climate change, where currently the greatest water quality knowledge gaps exist.

• Water quality data gaps are evident globally but are most pronounced in low-income countries.
• Regardless of the data availability, assessment procedures are often unsuitable for the protection or restoration of water bodies.
• Strengthening national organisations to monitor and assess water quality has multiple benefits.

Differentiating between natural and water quality changes caused by humans is essential to understanding complex freshwater ecosystems. Individual countries must be responsible for monitoring their water but to do that they must have access to the systems and processes that enable one to collect and manage data in order to efficiently assess the situation whilst applying logical and rigorous water-quality criteria. This conversion of data into knowledge will only be of use if the conclusions of such a process are well-disseminated and result in the implementation of effective solutions. This procedure is absent or inadequate in many countries and this is so, more often than not, in countries which desperately need solutions and sound decision making.

Freshwater around the globe is under extreme pressure due to numerous reasons. The onset of climate change has added yet another direct threat and another layer of uncertainty as to how these freshwater systems will confront the challenges of the future. This uncertainty is something that society cannot afford. For example, it is essential to know whether a lake will be able to support the current fishery or drinking water supply in five, ten- or twenty-years' time. Otherwise, one is not able to take effective remedial action. An active relationship between a supporting organisation and the country in question can provide useful information, but a global overview that permits society to appreciate the situation as a whole, whilst comparing the results of individual states has so far been unavailable. Climate change, pollution, habitat destruction and fragmentation, the extraction of too much groundwater and land use practices that are detrimental to freshwater ecosystem health mean that we are, at present, in uncharted territory.

Many of the countries that lack the capacity to monitor and assess their freshwater systems are in regions where climate change impacts are predicted to be felt most severely. Although a large number of countries do collect data, the quality of their freshwater systems still continue to deteriorate. The reasons for this degradation are often related to non-scientific issues such as inappropriate legislation or a lack of enforcement of existing regulations. However, much would still be gained if the information that is generated by the collection of data were properly assessed and transformed into the basis of realistic, effective action.

An assessment is effective if one knows how to understand the factors that have resulted in current water quality trends. This can be achieved by applying criteria based on the use of the water such as knowing the quality of water which is required for drinking or irrigation or factors that consider the health of the ecosystem in order to maintain natural or near-natural conditions. For the latter, the creation of a baseline is essential. If the state of the water quality in an ecosystem changes, the existence of a baseline allows one to identify such a deviation quickly and therefore take action to restore the situation far more effectively. The maintenance of freshwater systems permits society to preserve ecosystems and benefit human health, to ensure opportunities for employment and to guarantee the production of food. In order to achieve this, long-term water quality datasets and a robust assessment capacity are necessary. The capacity to identify gaps and establish where the capacity of individual countries requires support and strengthening represents an important first step in this process. Objective and reliable science-based information is needed to increase the capacity to resist climate change, especially in those countries at present, most at risk.

Scenario modelling shows a decreasing number of water bodies of “good quality’ by 2050, and increasing hotspots for toxic stress from chemical contaminants.

Anthropogenic contaminants are a growing concern. So far, more than 350,000 chemicals and mixtures of them have been registered for production and use, and numbers are increasing. As a result of their use, many of these chemicals find their way into freshwater systems and coastal waters.

The EU-project SOLUTIONS 1 has developed a method to determine to what extent the full range of man-made chemicals is likely to negatively affect the ecological status of surface water. As an indicator for the predicted environmental concentrations of these chemicals, a measurement known as the multi-substance potentially affected fraction of species (msPAF) is used, which ranges from 0 (no species affected) to 1 (all species affected). This indicator can be linked to the Sustainable Development Goal Indicator 6.3.2 "Proportion of bodies of water with good ambient water quality". Values below 0.05 (meaning less than five per cent of species are expected to be potentially affected) represent a low risk and can be seen as a good ambient water quality (shown on the maps below as green areas).

As part of the United Nations World Water Quality Assessment, and with co-funding from the United Nations Environment Programme, this method has been applied at a global scale, combining a high-resolution (1 km x 1 km) hydrological model (Wflow SBM: https://github.com/Deltares/Wflow.jl ) with the modules on emissions (D-Emissions) and water quality (D-WaterQuality). The models are setup using the open-source package hydromt ( https://deltares.github.io/hydromt/latest/ ), which is developed under the umbrella of the BlueEarth Digital Environment ( https://blueearth.deltares.org/ ).

Calculating quality

A Baseline calculation for 2010 and two different scenarios for 2050 have been simulated for future projections. The socio-economic pathway SSP2 (a middle of the road pathway or business-as-usual world) is combined with the RCP6.0 scenario and a more extreme combination of SSP5 (high growth of income, fossil fuel-based) in combination with high global average radiative forcing values of the RCP8.5 scenario.

In the Baseline situation in 2010 on a global scale 91 per cent of water bodies show a "good quality" (msPAF < 0.05), although large differences can be seen between the various global regions: the lowest percentage of water bodies with "good quality" are shown in the highly industrialized areas of Asia (76 per cent), Europe (83 per cent) and North America (84 per cent).

Rivers have been identified as a major pathway connecting land-sourced plastic with the oceans. Despite extensive research efforts there is still great uncertainty which rivers are the main contributors to ocean plastics. Recent studies suggest that small, urban rivers in large coastal cities can substantially contribute to plastic export into the oceans.

Key messages:

• Despite ongoing research, there is great uncertainty about the amount of plastic in the environment
• Plastics accumulate in terrestrial and aquatic environments, making them a long-term source to freshwater and the oceans even if the mismanagement of waste is stopped.
• Small urban rivers can contribute substantially to plastic export to the oceans
• Local actions to reduce inputs to rivers in urban coastal areas can effectively reduce plastic export to the oceans.
• Monitoring plastics in rivers, even by simple means such as counting floating objects, helps to shed further light on plastic transport in rivers and to confirm, for example, the success of measures to reduce plastic pollution in river

Plastics everywhere

Plastics as a product are a success story. Production of plastics has grown faster than GDP (Geyer et al. 2017). The properties of plastic that make it so successful, its durability, light weight and low cost production, are also the cause of its mismanagement and leakage. For example, about 40% of its production are single use items.

Since the presence of plastics in the oceans was first identified in the 1970s (Carpenter et al. 1972), plastics in the environment are now considered a global environmental problem. A growing number of studies have shown that plastics are found almost everywhere (Morales-Casalles et al. 2021). Their widespread occurrence and the fact that pollution of soils, lakes, rivers, and oceans is irreversible make plastic pollution a global environmental threat (MacLeod et al. 2021). Consequently, plastic production, waste generation and its fate in the environment are addressed by the Sustainable Development Goals (SDGs) established by the United Nations dealing with Sustainable Cities and Communities (SDG 11), Responsible Consumption and Production (SDG 12) and Life Below Water (SDG 14).

Furthermore, SDG 6 (Clean Water and Sanitation) has an indirect relation to plastics, as plastic garbage may block waterways and cause hygienic problems and plastics-associated chemicals can enter drinking water resources.

Groundwater

Protecting groundwater resources is necessary for safeguarding human health, maintaining food supplies, and conserving ecosystems. 

Protecting groundwater resources is necessary for safeguarding human health, maintaining food supplies, and conserving ecosystems. Many regions rely on naturally clean groundwater, as water treatment systems are too costly, so knowing where to source good quality groundwater is important.

Understanding groundwater quality

Groundwater provides about half of the world's drinking water and more than 40 per cent of agricultural water. It is a key freshwater resource for meeting the Sustainable Development Goals, 1 yet is not always included in water quality assessments.

Agriculture, urbanization, industry, population growth, and climate change all are threats to groundwater quality, as is the use of fertilizers, herbicides, fungicides and other pesticides.

Domestic wastewater systems are a source of numerous organic contaminants, as well as bacteria, viruses and macronutrients. 2 This is especially so where wastewater systems such as pit latrines and septic tanks are used near supply wells that access shallow groundwater. 3

Poor siting, operation and maintenance of groundwater supply infrastructure cause significant threats to groundwater quality and in severe cases render groundwater supplies unfit for consumption. 4 Pumping-induced salinity is a major threat to groundwater, particularly in coastal areas and more arid terrains, or in regions where groundwater levels are particularly shallow (e.g. due to wetlands, discharge zones) as well as areas of irrigation. 5

Climate change also poses numerous threats to groundwater quality. 6 These include sea-level rise, more intense storm surges affecting coastal aquifers, as well as more intense precipitation and flooding leading to greater ingress of surface contaminants and damage to groundwater infrastructure. Land use changes linked to changing climate are also a potential threat to groundwater quality as are changes in global temperatures, e.g. changing survival times for groundwater microbes and physical and biochemical reactions linked to carbon breakdown. 7

Natural contaminants

Two widely documented geogenic contaminants are arsenic and fluoride, although others include iron, manganese, chromium and radionuclides such as uranium, radium and radon. At high concentrations these can lead to serious health problems such as cancers in the case of arsenic, or dental and skeletal problems in the case of fluoride. Elevated iron and manganese concentrations commonly cause aesthetic - metallic taste and staining of cloth - and operational issues such as clogging of boreholes, pumps and water reticulation infrastructure, and can be a critical factor in the success of groundwater supply systems. Naturally occurring high salinity may also compromise groundwater quality and restrict use for drinking water and irrigation.

Assessing quality

A global groundwater quality portal 8 is being developed. Its aim is to be the focal point for global groundwater quality information and activities, to improve the global knowledge base, and to link to other portals and activities at regional to global scales.

A global groundwater quality assessment is needed because human activities and climate variability are increasing the pressure on groundwater resources.

Adapted from Misstear, B., Vargas, C.R., Lapworth, D. et al. A global perspective on assessing groundwater quality. Hydrogeol J 31 , 11-14 (2023). https://doi.org/10.1007/s10040-022-02461-0 

1 IAH (2017).

2 Lapworth et al . (2017).

3 Graham and Polizzotto (2013).

4 Misstear et al . (2017).

5 Foster et al. (2018).

6 Barbieri et al . (2021).

7 McDonough et al. (2020).

8 IGRAC (2021).

A number of tools to aid in assessing water quality is available. Some of them are featured here.

Assessing world water quality brings together a range of scientific disciplines and methodologies, as well as consideration of human-influenced factors such as urbanization, pollution and climate change. Reflections on some of those issues appear here.

Data Resources The World Water Quality Hub congregates a range of freshwater quality data and platforms from different sources, providing an extensive collection for users to explore.

Data is an integral part of any assessment as it  as it enables understanding of the current state of water quality, identifying trends and patterns, and the development of effective management strategies and policies.

The World Water Quality Hub congregates a range of freshwater quality data and products from different sources, providing an extensive collection for users and serving as a place for collaboration.

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Nzers reluctant despite significant economic and environmental benefits from pine forestry - research.

Pine forestry offers a tempting alternative for land use that has economic and environmental benefits, researchers say. Photo:

Rivers and lakes could be cleaned up with profits still generated for landowners by converting sheep and beef farms to pine trees, according to a new paper from the Our Land and Water science challenge.

But the authors questioned whether New Zealanders want a sea of pine.

Four different research projects, using different models and involving different researchers, all found New Zealand was heading towards having many more pine trees.

The big push to pine was being driven by a combination of attractive prices for carbon credits generated by pine trees, the poor economics of sheep and beef and the need to improve water quality.

All three factors together were going to cause a significant change, said the lead author of a paper pulling together the findings, Dr Bill Kaye-Blake, a principal economist at economic consultants NZEI (NZ Institute of Economic Research).

"The easiest solution is to plant a lot of pine trees. Now that's probably not acceptable to a lot of people in New Zealand, to a lot of rural communities in New Zealand," said Kaye-Blake.

Even with a carbon price of zero, about a fifth of sheep and beef land would still be converted to pine forests, the research found.

About half the conversions were driven by carbon credits, 20 percent by low profits from sheep and beef and 15 percent or so was for meeting water quality targets, he said.

Poor profits from sheep and beef were "simply a result of the current economic conditions," Kaye-Blake said.

"If you look at pine trees, there is a strong market for logs and a strong market for timber products, so forestry is making a lot of money, and on the other side sheep and beef are struggling a bit.

"In particular, if we look at wool, the cost of shearing the sheep is almost more than the cost of the wool clip you get from that."

The studies showed New Zealand could have cleaner lakes, rivers and beaches, with more pine, he said.

And water quality benefits of pine forest versus sheep and beef farms included lower nitrogen pollution and lower e-coli in the water.

"One group of researchers looked at the Tukituki catchment in Hawke's Bay and found meeting the water quality bottom lines would mean changing most of the sheep and beef land into pine forests.

"It also found if the region did that it would increase profit to land owners in the area, so you have both a water quality benefit and an economic benefit."

• Freshwater contamination a challenge for New Zealand land use
• Water quality of almost all surveyed lakes and rivers very poor

But Dr Kaye-Blake said the models could not include the downsides of pine plantations such as lower biodiversity, sediment run-off and damage to bridges and houses from debris washing away in storms, as has happened in Tai Rāwhiti.

"There are also negative impacts that aren't actually included in these models, one of the big ones for example is forestry debris."

• Large slash must now be removed after harvesting - new forestry regulations
• Environmental group hails court decision against forest company

Our Land and Water challenge director Dr Jenny Webster-Brown said the findings of the four studies were "surprisingly consistent" that pine was the "best, easiest, most obvious option", but asked if New Zealanders would be happy with the cost of a pine-filled landscape.

"We appreciate that having more pine trees is not the solution to New Zealand's problems," she said.

The researchers concluded that if the government wanted to change the direction of land use it should look at options like encouraging more native trees and biodiversity.

• Planting pine or native forest for carbon capture isn't the only choice - NZ can have the best of both
• The future forest industry - Our Changing World

Finding ways to make sheep and beef more profitable would also help, because it could give farmers more money to tackle water pollution problems without converting their land to pine, they said.

In all they made eight recommendations.

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The water resources group at the University of Idaho's Kimberly Research and Extension Center is a national leader on consumption of water by irrigated agriculture and natural systems. The group also conducts research on water quality and hydrology. The group has developed the METRIC platform for transforming satellite imagery into maps of water consumption and the REF-ET and ETIdaho systems for calculating reference crop ET and for reporting crop water requirements for the State of Idaho. For irrigation water management issues, please visit the Irrigation Water Management  page.

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• Open access
• Published: 19 July 2022

Measuring the gaps in drinking water quality and policy across regional and remote Australia

• Paul R. Wyrwoll   ORCID: orcid.org/0000-0001-6455-1766 1 , 2 ,
• Ana Manero   ORCID: orcid.org/0000-0002-3636-9534 1 ,
• Katherine S. Taylor   ORCID: orcid.org/0000-0002-6675-3852 1 , 3 ,
• Evie Rose 1 &
• R. Quentin Grafton   ORCID: orcid.org/0000-0002-0048-9083 1  

npj Clean Water volume  5 , Article number:  32 ( 2022 ) Cite this article

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Drinking water quality remains a persistent challenge across regional and remote Australia. We reviewed public reporting by 177 utilities and conducted a national assessment of reported exceedances against the health-based and aesthetic guideline values of the Australian Drinking Water Guidelines (ADWG). Four definitions of a basic level of drinking water quality were tested to quantify service gaps across regional and remote areas of each subnational jurisdiction in 2018–2019. At least 25,245 people across 99 locations with populations <1000 reportedly accessed water services that did not comply with health-based guideline values. Including larger towns and water systems, the estimated service gap rises to at least 194,572 people across more than 115 locations. Considering health parameters and the ADWG definition of ‘good’ aesthetic characteristics, the reported service gap rises further to at least 627,736 people across 408 locations. Forty percent of all locations with recorded health exceedances were remote Indigenous communities. Monitoring and reporting gaps indicate that the actual incidence of non-compliance with the guideline values of the ADWG could be much higher than our estimates. Our results quantified the divergence in the assessment of water quality outcomes between Sustainable Development Goal Target 6.1 and the ADWG, demonstrated disparities between service levels in capital cities and the rest of Australia, and highlighted the need for place-based solutions. The methods and dataset provide a ‘proof-of-concept’ for an Australian national drinking water quality database to guide government investments in water services.

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Introduction.

The United Nations 2021 Sustainable Development Report indicates that Australia has achieved Sustainable Development Goal (SDG) Target 6.1 1 . Notwithstanding high service standards in large cities and the resolution of several recurring boil water alerts in recent years (e.g. 2 , 3 ), ‘universal and equitable access to safe and affordable drinking water for all’ does not yet exist across Australia 4 , 5 , 6 . Poor drinking water quality and access remain barriers to improved health and economic outcomes in many Australian regional and remote communities 7 , 8 , 9 .

Australia’s gaps in drinking water quality are not unique among high-income countries that are reportedly close to or already achieving SDG Target 6.1. For example, deficiencies in safe water access have resulted in the following: at least US$15 billion legislated to replace lead pipes and control water contamination in the United States 10 ; C$7.6 billion in actual and planned spending to end 162 long-term boil water advisories and improve water and wastewater systems in First Nations communities in Canada 11 ; and NZ$3.6 billion to upgrade New Zealand’s water networks and overhaul policy and regulatory frameworks 12 .

Major public investments in Australia’s drinking water infrastructure have been identified as a national policy priority 13 , 14 , 15 . In the context of that reform agenda, the Productivity Commission (PC) – the Australian federal government’s independent advisory agency on economic, social, and environmental reform – recommended that subsidies to water suppliers in high-cost locations should be designed to ensure affordable access to a ‘basic level of service’ that, at a minimum, includes safe and reliable drinking water 6 . This 2021 PC recommendation is supported by organisations representing Indigenous peoples 16 , health and community service providers 17 , 18 , water utilities 19 , and local governments 20 .

The Australian Drinking Water Guidelines (ADWG) provide the national framework for describing, managing, and monitoring drinking water quality 21 . Although they are not mandatory national standards, ADWG health-based and aesthetic guideline values for microbial, physical, and chemical characteristics provide a basis for state and territory government water quality regulations (e.g. 22 , 23 ), industry norms for external reporting (e.g. 24 ), and federal government water policy (e.g. 25 , 26 ). The ADWG specify that guideline values should inform short- and long-term monitoring of service improvements, with the key performance measure being no detection of E. coli in the distribution system. Health-based guideline values for chemical parameters are conservatively estimated and most, but not all, relate to life-time exposure. Aesthetic guideline values for physical characteristics ensure “good quality water – that is, water that is aesthetically pleasing and safe, and that can be used without detriment to fixtures and fittings” 21 . Notably, the focus of the ADWG on good aesthetic quality represents a higher standard than the guidelines of the World Health Organisation which emphasise acceptable quality 27 ; in practice, this is reflected in Australian guideline values being lower than most other countries for some key aesthetic parameters, including hardness, sodium, and total dissolved solids 28 .

Section 3.10.2 of the ADWG state that water suppliers should produce an annual public report summarising performance against numerical guideline values to support evaluation of service improvements and “ensure that drinking water quality management is open and transparent” 21 . In terms of monitoring, the ADWG highlight that “it is neither physically nor economically feasible to test for all drinking water quality parameters equally” 21 . Instead, monitoring should focus on key health-based and aesthetic characteristics, including potential contaminants identified in water system and hazard analysis. In practice, state and territory regulations or regulatory bodies specify guideline values which water suppliers must report against and any specific requirements or exemptions relevant to particular water systems (e.g. 29 ). Figure 1 summarises the role of guideline values in the ADWG and the adoption of annual reporting across jurisdictional regulatory frameworks.

Text in italics indicates regulatory documents referencing ADWG guideline values. Whether meeting health-based guideline values is mandatory varies across jurisdictions, parameters, and by the type of water supplier. Aesthetic guideline values are typically incorporated as non-mandatory objectives and/or reporting requirements only, except for turbidity in Victoria. Minimum standards for tested parameters and sampling frequencies may be specified across all suppliers in a jurisdiction or determined through tailored monitoring plans. New South Wales is the only jurisdiction where public annual reports are not a formal requirement; for other jurisdictions, non-public annual reporting to regulators only is typically required for water carters and very small suppliers. Icons downloaded from the Noun Project ( https://thenounproject.com/ ) using a NounPro for EDU Subscription.

Despite widespread monitoring and reporting against ADWG health-based and aesthetic guideline values, data collation at the national level is incomplete. The Urban National Performance Report (NPR) 30 – the annual review used to report against SDG Target 6.1 – encompasses the 85 utilities and other suppliers of drinking water that serve more than 10,000 connections. The most recent figure from Australia’s SDG reporting – 98% of the population using ‘safely managed drinking water services’ in 2017 31 – does not cover people accessing water from smaller utilities and suppliers nor private supplies. Approximately two million people, or 8% of Australia’s population, are thereby unrepresented in national statistics for drinking water access. Five of the 166 Urban NPR indicators directly concern drinking water quality (see Table 1 for an overview and 2018–2019 values).

At the sub-national level, there is a wealth of detailed annual reporting against ADWG health-based and aesthetic guideline values in the service areas of major utilities and all capital cities except Sydney (see 32 , 33 , 34 , 35 , 36 , 37 ). Outside these areas, public reporting can be fragmented, as in the case of Australia’s most populous state (New South Wales) where regional drinking water quality data is recorded in a centralised government database that is not publicly accessible (see 38 ), utilities are not required to publish annual reports, and the most comprehensive data are summary statistics for each local water utility on health-based microbial and chemical ADWG compliance 39 . Monitoring and reporting gaps are prevalent in very remote areas across Australia. For example, a 2021 audit found that the Western Australian government agency supplying remote water services did not conduct any routine drinking water quality testing in 51 small Indigenous communities 40 .

Greater transparency and public accountability could support more effective delivery of government programs. In 2020, the Audit Office of New South Wales found that the responsible government department had not effectively supported regional town water infrastructure planning since at least 2014, lacked an evidence-based approach to investment decisions, and “lack of internal procedures, records and data mean that the department cannot demonstrate it has effectively engaged, guided or supported [local water utility planning]” 41 . Unsafe and insecure access to water services in remote Indigenous communities remain a widely recognised national policy issue (e.g. 6 , 14 , 40 ) despite government inquiries 42 , 43 , 44 , 45 , academic research 7 , 46 , 47 , 48 , 49 , 50 , 51 , and media reporting 52 , 53 , 54 , 55 , 56 , 57 across decades. Many factors can contribute to this complex policy challenge. High operating costs, harsh environmental conditions, remoteness, and barriers to collaborative management (see 49 for a review) are amplified by the historical and ongoing prevalence of Indigenous water injustice in Australian water policy 9 , 58 , 59 , 60 , 61 , 62 . In terms of guiding policy to improve water services in remote locations, the establishment of quantitative community service indicators is a significant recent reform of the national initiative to address disparities in life outcomes between Indigenous and non-Indigenous people 63 . Federal government agencies have also highlighted the need for better monitoring and reporting to guide public investments in expanding access to safe and reliable drinking water services 6 , 14 .

This paper assesses the publicly available data, highlights key data gaps, and quantifies the populations and locations where reported drinking water quality did not meet basic levels of service defined in relation to the ADWG. First, we outline four possible approaches to defining basic levels of drinking water quality in the Australia context. Second, we construct a national dataset of exceedances against ADWG health-based and aesthetic guideline values from reporting data across 177 utilities for the financial year 2018–19. Third, we match water quality, population, and location data to estimate the number of people and locations by state or territory jurisdiction where basic levels of service were not met at least once. Fourth, we examine the data to identify key health and aesthetic exceedances, contrast outcomes between capital cities and remote Indigenous communities, and highlight the data gaps. We conclude with a summary of the study’s limitations and the steps toward establishing a publicly accessible national drinking water quality database for Australia.

Definitions of a basic level of drinking water quality

We provide four alternative definitions of a basic level of drinking water quality with reference to the ADWG and SDG Target 6.1 indicators:

‘Sustainable Development Goal (SDG) 6.1’ – Water quality results do not exceed ADWG health-based guideline values and any associated state/territory annual compliance standards across all reported samples of the fecal contamination (E. coli) and 2 priority chemical (arsenic, fluoride) parameters specified by the WHO/UNICEF JMP for SDG Target 6.1 monitoring (excluding false positives);

‘ADWG Health’ - Compliance with all ADWG health-based guideline values – Water quality results do not exceed ADWG health-based guideline values and any associated state/territory compliance targets for all reported samples across the microbial contamination performance measure (E. coli), 212 chemical parameters, and radiological quality (excluding false positives);

‘ADWG Good’ - Compliance with all ADWG health-based guideline values and the ADWG aesthetic guideline values for physical characteristics beyond which the quality of the water might no longer be regarded as ‘good’ – ADWG Health definition plus the mean annual results for 6 physical characteristics (true colour, turbidity, hardness, total dissolved solids (TDS), pH, dissolved oxygen) across reported samples do not exceed aesthetic guideline values;

‘Metropolitan’ - Compliance with all ADWG health-based and aesthetic guideline values – ADWG Good definition plus the mean annual results for 25 chemical parameters (e.g. chlorine, sodium, iron, manganese, chloride) across reported samples do not exceed the higher of: (i) the corresponding ADWG aesthetic guideline value, or (ii) the highest mean value reported for the capital city of the corresponding state/territory jurisdiction.

The SDG 6.1 definition supports assessment of how Australia-wide reporting of access to ‘safely managed water services’ under the Sustainable Development Goals might change if available data from smaller water suppliers were included in national reporting. The ADWG Health definition provides insights into the number of people and locations where public investments may be required to ensure a basic level of drinking water quality focused only on health parameters. Note that the inclusion of jurisdictional compliance targets integrates existing approaches to a ‘basic level of service’ (e.g. E. coli. annual compliance of 99.8% in South Australia, 98% in Tasmania and Queensland).

The ADWG Good definition reflects the ADWG definition of ‘good’ water quality and the emphasis in the guidelines on water suppliers meeting consumer expectations. In practice, accounting for aesthetic considerations in defining basic service levels is necessary because: (i) unpalatable water affects consumer risk perceptions, potentially leading to indirect health impacts from accessing unsafe alternative sources of hydration 48 , 64 , 65 , including sugary drinks 66 , 67 ; (ii) buying bottled or trucked water due to distrust of water services 68 , 69 is a financial burden for low-income households inconsistent with affordable access; and (iii) high levels of hardness and TDS may affect water infrastructure integrity, operational costs, and safety 70 . Note that the ADWG definition of ‘good’ water also includes ‘taste and odour’ which is specified as “not offensive to most people” 21 . This characteristic does not have an assigned numerical value as non-compliance can have numerous causes, including the presence of microorganisms in raw water.

The Metropolitan definition provides a benchmark for assessing the gap in drinking water quality between regional/remote areas and capital cities – where most of Australia’s population lives and non-compliance with aesthetic guideline values rarely occurs. Given that any reported monitoring against all guideline values is incorporated into this definition, it provides an upper bound for a basic level of drinking water quality that reflects the breadth of criteria defined by the ADWG.

Service gaps by population, location, and jurisdiction

Tables 2 – 5 provide a breakdown of the exposed population and number of locations where public reporting indicates that basic levels of drinking water quality were not met at least once during the 12-month reporting period. Overall, we estimated that at least 194,572 people across regional and remote areas of Australia accessed water supply systems that did not meet the ADWG Health level of service in 2018–2019. The detailed analysis that follows does not include New South Wales due to limited data availability for that jurisdiction (see Methods section for further details).

Excluding New South Wales, we estimated that at least 174,488 people in 115 locations were exposed to non-compliance with the ADWG Health benchmark. Incorporating aesthetic parameters, these estimates increased to at least 627,736 people in 408 locations ( ADWG Good ) or at least 1.4 million people in 819 locations ( Metropolitan ). By contrast, only an estimated 41,169 people in 35 locations where data were available did not have access to water services meeting the SDG 6.1 definition. For context, these population estimates equate to at least 0.7% ( SDG 6.1 ), 3.1% ( ADWG Health ), 11.1% ( ADWG Good ), and 25.0% ( Metropolitan ) of the approximately 5.7 million people living outside capital cities in 2018–19.

We reported the number of locations alongside population estimates and partitioned the results by location size because one exceedance in larger water systems can strongly influence total population estimates. For example, exceedances for trihalomethanes and chlorine in two regional Queensland centres (populations of 52,073 and 22,206) were the primary source of the total population estimates for the ADWG Health definition. Similarly, 99.6% annual E. coli compliance across 8 towns within a regional water supply system dominated the results for the SDG 6.1 level of service in South Australia and overall. The removal of that single exceedance from the sample would reduce the Australia-wide exposed population for the SDG 6.1 definition from 41,169 to 13,324, but not the corresponding estimate for the ADWG Health benchmark because only 72.8% of samples from that system complied with the guideline value for trihalomethanes in 2018–19.

We highlight that 33 health exceedances were not included in the assessments of service level coverage where either the water supplier demonstrated that the sample was a false positive, jurisdictional compliance targets were not breached across the annual reporting period, or the cause may have been a data entry error. The very high population estimates for lack of access to the Metropolitan benchmark was because of the prevalence of chlorine samples exceeding odour thresholds. Removing that parameter from the latter definition would reduce the exposed population to 634,879 people across 422 locations.

Notably, 99 of the 115 locations where residents accessed a water system reportedly not achieving the ADWG Health benchmark were smaller towns and settlements with less than 1,000 people (Fig. 2 ), and 62 of these are classified as ‘Remote’ or ‘Very Remote’ by the Australian Bureau of Statistics (ABS) Remoteness Area classification 71 . Across jurisdictions, the estimated populations where basic levels of drinking water quality were reportedly not achieved varied markedly according to different definitions (Fig. 3 ). Overall, the most common exceedances against health-based guideline values were for trihalomethanes, nitrate, E. coli, and fluoride (Fig. 4 ). Aside from chlorine and pH, the most common aesthetic exceedances involved hardness, sodium, and TDS; Fig. 5 shows the range in reported exceedances for those three parameters.

New South Wales shaded due to lack of information on location, parameter, and exact values associated with reported exceedances. Locations not shown where a single exceedance was reported as a false positive or total exceedances did not lead to non-compliance with annual jurisdictional compliance targets.

a Northern Territory. b Queensland. c South Australia. d Tasmania. e Victoria. f Western Australia. Source data are provided as a Source Data file.

Size of coloured rectangles represents the percentage of exceedances associated with the corresponding parameter. Total of 105 exceedances included. Multiple exceedances in the same location against the same health parameter considered to be a single exceedance. Exceedances reported as false positives or not leading to non-compliance with annual jurisdictional compliance targets are not included. 99.1% compliance with Trihalomethanes target across 17 towns in SA Water Barossa system considered to be a single exceedance for this diagram. Single exceedances for Antimony, Barium, Dichloro‐acetic and Trichloro‐acetic Acid, PFHxS/PFOS not displayed. Source data are provided as a Source Data file.

a Hardness. b Sodium. c Total dissolved solids. Note: No public data available for water systems supplied by the Tasmanian government-owned water utility and New South Wales local water utilities. Source data are provided as a Source Data file.

Geographic gaps

We identified 4 health exceedances across water systems serving approximately 10.2 million people in Australian state and territory capital cities in 2018–19 (not including Sydney). This estimate does not include 7 E. coli exceedances that did not result in non-compliance with an annual jurisdictional target. A total of 18 aesthetic exceedances were identified, including 16 for chlorine and 2 for TDS.

The high service levels observed in capital cities contrast with outcomes in those remote Indigenous communities where drinking water quality was monitored and reported. Table 6 presents a summary of reported health and aesthetic exceedances across those communities. For the ADWG Health definition, the 48 exposed communities comprised 40% of all locations across Australia where that benchmark was reportedly not achieved.

Monitoring and reporting gaps

The dataset underlying our analyses was compiled from a review of publicly available sources. Table 7 provides an overview of the substantial monitoring and/or reporting gaps identified. These gaps mean that all estimates of populations, locations, and proportions are likely to be a lower bound for each definition. A major gap in terms of population coverage is New South Wales where, unlike the rest of Australia, production of annual drinking water quality reports is not a regulatory requirement for any water suppliers. In this jurisdiction, our review found only 18 of 81 local water utilities provided sufficient data to assess compliance against health-based and aesthetic guideline values of the ADWG. Approximately 1.2 million people are served by the remaining 63 local water utilities. Across the 68 water utilities in Queensland, we identified 24 where monitoring and reporting issues, such as no testing of chemical parameters, may have contributed to the lack of reported exceedances. Our review did not identify a public data source in any jurisdiction or nationally for drinking water quality from private supplies or water carting.

Our work provides three main contributions and related implications. First, we demonstrated methods to define and apply basic levels of service for drinking water quality. In practice, our definitions provide starting points for determining which specific parameters and target values would be applied in each jurisdiction. Further, the recording of noncompliance with quantitative benchmarks to prioritise locations for subsidies could be extended to reliability, affordability, and other components of basic levels of service. Section 3.8.1 of the ADWG emphasises that customers should play a central role in determining service levels 21 . In supporting a Productivity Commission recommendation on improving monitoring and reporting in remote Indigenous communities, the Northern Land Council highlighted “the need for individual communities to be actively involved in determining their required level of service and hence requirements for water service provision” 16 . Extending this approach to basic levels of service may require governments to conduct state- and territory-wide participatory processes for customers to determine and revise benchmarks. Such processes may draw on a growing body of research and practice on the recognition, representation, and realisation of Indigenous values, knowledge, and rights in Australian water policy (e.g. 59 , 62 , 72 , 73 , 74 , 75 , 76 , 77 , 78 ). In the context of drinking water services in remote Indigenous communities, empirical research has informed strategies and actions to enable collaborative governance with external actors, including conducting local water baseline assessments, culturally-informed and long-term engagement, developing local employment opportunities, working with community champions, and delivering education and capacity-building programs in local languages 49 , 79 .

Second, our analysis provides an improved understanding of drinking water quality in regional and remote Australia compared to national reporting under the Urban NPR. We demonstrated that there are substantial differences across drinking water quality service levels. In terms of SDG Target 6.1, we showed that this definition represents a minimal approach relative to the ADWG, albeit one that has not yet been achieved. In terms of SDG reporting and the Australian Government’s next Voluntary National Review, we highlighted the existing opportunities to expand coverage beyond large water utilities and use existing public data to represent the Australia-wide drinking water quality situation more accurately. Proposed public investments to improve monitoring and reporting in remote areas would further address the inconsistency between real-world water quality outcomes and national-level statistics 14 .

Third, we showed that exceedances beyond ADWG guideline values are most prevalent in small and remote towns and settlements, and especially remote communities. Thus, policy initiatives seeking to improve drinking water services may need to carefully consider and adapt to cultural and geographic contexts 3 , and incorporate training, improvements to source water quality, and other non-capital investments 80 . In Australia, full-cost recovery from customers is the guiding principle determining the financial management of water utilities 81 . Many local water utilities that supply regional Queensland and New South Wales have small customer bases and incur high operating costs. Regional and remote locations typically exhibit higher incidence of socio-economic disadvantage. Consequently, programs to ensure basic levels of service need to account for costs, the ability to pay, and other place-specific constraints on delivering improved drinking water services. Further, some communities currently lack water service provision altogether. For communities where water quality is not monitored, water quality issues may be ‘invisible’ and these data gaps should be prioritised for resolution.

We contend that a national drinking water quality database is a pre-requisite to defining and measuring basic levels of service within each Australian state and territory jurisdiction. A multi-stakeholder co-design process would be required to establish and maintain the database, including decision-making processes and data practices consistent with Indigenous Data Sovereignty and Governance where applicable (see 82 , 83 ). A publicly accessible database could: inform participatory processes to define service levels; support the identification of priority locations for government subsidies and other investments; provide a focal point for engagement between utilities and consumers; monitor outcomes over time; enable better understanding of the determinants of service improvements; and build trust between consumers, suppliers, and policy-makers. Figure 6 highlights government agency programs and processes at federal and sub-national levels that could be informed by the database. Given the broad scope of policy applications, and the important role of accessible open data in promoting accountability of public organisations 84 , an independent statutory body at the federal level may be an appropriate data custodian.

(E) Existing programs and processes, (P) Proposed programs and processes, (U) Under development programs and processes.

The ADWG are subject to a rolling bi-annual review and updated regularly. As new evidence is generated on the potential health risks of chemical contaminants (e.g. 85 ), and new programs developed to address specific water quality issues (e.g. 86 ), a national database would support targeted policy responses as guideline values are updated. Moreover, the collation of historical data could support epidemiological research on exposure to water contaminants and the incidence of chronic and acute health conditions.

Our compilation of ADWG exceedances is a ‘proof-of-concept’ for an Australian national drinking water quality database. A key practical requirement would be to mandate Australia-wide standardised or minimum reporting conventions within jurisdictional regulations, including summary statistics for water quality parameters (e.g. minimum, maximum, 95th percentile, and average values), number of samples collected, and number of exceedances. Subnational regulatory reforms for standardised monitoring and reporting, including compulsory public reporting for local water utilities in New South Wales, could be initiated through the proposed renewal of the Intergovernmental Agreement on a National Water Initiative 6 . The value of a national drinking water quality database would be enhanced by the inclusion of indicators for water-borne disease outbreaks; key risks associated with source water quality, such as cyanobacterial blooms and bushfires; and the other aspects of basic levels of service, such as affordability and reliability, determined by state and territory jurisdictions. Furthermore, the integration of source water quality monitoring results would improve the transparency of government agencies’ performance against the objectives of water resource management frameworks, such as the Murray-Darling Basin Plan 26 .

Insights on the design and potential uses of a national drinking water quality database for Australia could be gained from: (i) the Safe Drinking Water Information System in the United States 87 , (ii) public information on short-term and long-term drinking water advisories provided by Indigenous Services Canada 88 , 89 , and (iii) the former Drinking Water Online database of the New Zealand government 90 .

Our analysis showed that national reporting on SDG 6.1 and water utility performance in Australia obscures inequities in water access: metropolitan versus regional and remote; Indigenous versus non-Indigenous communities; monitored versus unmonitored water supplies. Official reporting of high-income countries close to or already achieving SDG Target 6.1 perpetuates a myth of universal, clean, affordable, trustworthy, and uniformly governed water access 91 . The reality in reportedly high-performing countries, including Canada 92 , 93 and the United States 94 , 95 , 96 , is that water access is uneven and many challenges remain 97 , 98 . Race, income, housing, geography, and utility size correspond to gaps in water access and drinking water quality 94 , 95 , 97 , 99 . Societal power imbalances, colonial practices of the state, and fragmented governance can (re)produce unsafe, unacceptable, and untrusted water services in Indigenous communities 93 , 100 , 101 . The geographic and monitoring/reporting gaps described in this paper reflect the structural barriers to sustainable improvements in water services 49 , 97 .

Here, we show that the inequities in high-income countries become more visible when locally-contextualised benchmarks are used (e.g. ‘ADWG Good’). Notwithstanding the benefits of the SDGs to galvanise global action, there are inherent difficulties in using standardised global indicators to measure progress toward the goal of ‘universal and equitable access to safe and affordable drinking water for all’ 102 , 103 , 104 , 105 . Supplementing country reporting against SDG 6.1 with benchmarks relevant to local policy, such as the definitions of a ‘basic level of drinking water quality’ for Australia proposed in this paper, can improve awareness of who has affordable access to good quality water, who does not, the structural factors involved, and increase accountability of governments and broader society for the gaps.

Our results are subject to multiple limitations. First, our dataset provides a snapshot of a single year and does not provide insights into service performance across time. Since 2018–19, investments have improved water quality in some locations where ADWG health exceedances occurred (e.g. 106 ), and new exceedances have emerged in others (e.g. 107 ). Second, our population estimates are less reliable for those locations where utilities do not provide data on the serviced population. Third, our analyses did not account for: contaminants subject to a jurisdictional requirement that have no ADWG health-based guideline value, such as the Naegleria fowleri amoeba in Western Australia 40 ; breaches of operational guidelines, such as free residual chlorine in the reticulation network falling below 0.2 mg/L; boil water notices or drinking water advisories (e.g. 108 ); and locations that experienced severe disruptions, taste and odour issues, or other causes of poor quality services not reflected in water quality reporting (e.g. 57 ). Fourth, our analyses did not distinguish between prolonged versus occasional non-compliance with water quality guidelines. This is due to a lack of standardised reporting conventions across jurisdictions. Fifth, the analyses did not account for variable incidence and frequency of testing parameters; the absence of monitoring or reporting for a contaminant does not mean it is not present. Sixth, many small remote Indigenous communities in Australia are not provided with water services by external suppliers and, consequently, limited or no water monitoring occurs. These communities exposed to (arguably) the highest risk of unsafe drinking water are also those least represented in water quality reporting

Finally, we focused on the outcome-based drinking water indicators provided by ADWG health-based and aesthetic guideline values. Improved water quality monitoring and reporting is necessary but not sufficient: outcome-based indicators need to be combined with structural and process indicators 104 ; data are not always used effectively 109 ; test results provide snapshots of water quality at points in time and an incomplete picture of all potential hazards 105 ; and governance challenges for remote water supply systems require a portfolio of solutions 97 .

National review of publicly available drinking water quality data

Our research focused on publicly available drinking water quality data to ensure that the methods and results are transparent, replicable and adaptable by policy-makers, and consistent with Section 3.10.2 of the ADWG and Principles 5, 9, 10 and 12 of the OECD Principles on Water Governance 110 . We identified 177 drinking water suppliers from the Urban NPR and state/territory government agency websites. This sample predominantly includes large state-owned water corporations and small local water utilities that are subject to public health regulation and, in all jurisdictions except New South Wales, annual public reporting requirements. We searched each supplier’s website to obtain annual drinking water quality reports for the financial year 2018–2019. We also searched the websites and archives of government agencies and regulators for other drinking water quality information. Where these methods did not yield results for a specific water supplier, we also used relevant search terms in the Google search engine (e.g. ‘Cloncurry drinking water management plan 2019’).

For Queensland and New South Wales, we used the Wayback Machine internet archive ( https://archive.org/web/ ) to search for 2018–19 reports that were not available on the current version of council webpages. In New South Wales, we obtained 25 local water utility reports, documents, or webpages providing water quality information. However, only 18 provided sufficient data to support our analysis. Hence, we relied on aggregated ADWG health-based compliance data for New South Wales 39 which does not provide information by town, water system, nor health parameter, and does not report against aesthetic parameters. For each of the 177 utilities across Australia, we recorded: data availability; year if not 2018–19 (see further below); classified each utility as either ‘Capital City’, ‘Regional/Remote’, or ‘Mixed’; and whether there were issues with limited sampling or reporting that could affect the analysis.

Our review yielded annual drinking water quality reports and data for regional and remote locations from (i) the annual reports of 22 state/territory government-owned water utilities; (ii) 4 local government or mining company-owned small water utilities in Western Australia; (iii) annual drinking water management plans of 65 local council-owned utilities in Queensland, (iv) a Western Australian Auditor-General audit of service provision in 143 remote Indigenous communities by the Western Australian Department of Communities, and (v) summary information on health compliance for microbial and chemical parameters for 81 New South Wales local water utilities. For each supplier, we collated drinking water quality data for the smallest geographic unit available, e.g. each water supply zone, which was then defined as a ‘location’ in the analysis. All data points relate to samples from the reticulation network. We also reviewed annual drinking water reports of 12 water utilities serving customers across 7 Australian capital cities. The Australian Capital Territory was not included in the analysis of regional and remote areas because its population is almost entirely located within the capital city of Canberra. The data on remote and regional locations excludes all locations in outer metropolitan areas classified as ‘Major Cities’ under the ABS Remoteness Area structure 71 . The ‘References’ tab in the supporting dataset 111 provides links to all data sources.

All data is for the financial year 1st July 2018 to 30th June 2019, except for 22 Queensland local utilities where we used data from 2017–2018 or the most recent year available and 40 which reports water sampling conducted across the 2019 and 2020 calendar years. The year from 2018–2019 was chosen for analysis because it was the most recent year available, except for 2019–2020 when major bushfires across Australia affected source water quality and interrupted monitoring activities in many locations. Figure 7 provides a summary of the methods. All data are provided in the supporting dataset 111 .

Icons downloaded from the Noun Project ( https://thenounproject.com/ ) using a using a NounPro for EDU Subscription.

Recording and assessment of ADWG exceedances

We recorded average, maximum, 95th percentile values and/or number and percentage of exceedances for all locations where a drinking water quality parameter was reported to not comply with ADWG health-based and aesthetic guideline values. Note that a single exceedance triggers non-compliance with ADWG health-based guideline values and we followed ADWG rounding conventions. Non-compliance with aesthetic guideline values relates to the average annual value of testing results. Evidence and references for 33 health exceedances that were reported as false positives, may have been caused by data entry errors, or did not breach annual compliance targets are provided under ‘Health Comment’ in the jurisdictional worksheets in the supporting dataset 111 .

Matching ADWG exceedances to population and location data

We used the following hierarchy to estimate and source population data: (i) data provided by the water utility; (ii) population data from the ABS 2016 Census on the corresponding Urban Centre and Locality (UCL), State Suburb (SSC), or Indigenous Locations (ILOCs) (in that order of availability); and (iii) population data for remote communities from government organisations.

Population data values and sources for each location are provided in the supporting dataset 111 . Note that UCL statistical areas correspond to densely populated urban areas and, for smaller regional or remote settlements, only those with populations greater than 200. Consequently, UCL data may have underestimated the population in a given location exposed to exceedances because water supply systems may extend beyond the UCL boundary. Conversely, SSC and ILOC statistical areas in regional and remote locations include non-urban households that may not be connected to the water supply system. Hence, SSC and ILOC data potentially overestimated the exposed population for towns with less than 200 residents. For South Australia, Tasmania, and Queensland, drinking water quality data in some locations were reported for systems encompassing multiple towns. In these cases, it was assumed that system-wide ADWG exceedances applied to all towns within the system. We were unable to source population data for 4 locations.

We classified all regional/remote locations according to the ABS Remote Area structure. Remote Indigenous communities were identified in the dataset as those communities serviced by the Remote Areas Essential Services Program (Western Australia), Indigenous Essential Services (Northern Territory), classified as remote Aboriginal communities served by South Australia Water Corporation, or locations within Queensland Aboriginal Shire Councils or Torres Strait Island Regional Council classified as ‘Remote’ or ‘Very Remote’.

Data availability

The dataset generated and analysed in this study is available through Open Science Framework 111 . The source data for figures and tables are provided with this paper.

Sachs, J., Kroll, C., Lafortune, G., Fuller, G. & Woelm, F. Sustainable Development Report 2021 . Sustainable Development Report 2021 (Cambridge University Press, 2021).

Department of Health. Water Quality of Public Drinking Water Supply Systems in Tasmania: Annual Report 2018-19 . https://www.health.tas.gov.au/__data/assets/pdf_file/0007/421189/Annual_drinking_water_quality_report_2018-19.pdf (2019).

Hall, N. L. et al. Drinking water delivery in the outer Torres Strait Islands: A case study addressing sustainable water issues in remote Indigenous communities. Australas. J. Water Resour. 25 , 80–89 (2021).

Google Scholar  

Howey, K. & Grealy, L. Drinking water security: the neglected dimension of Australian water reform. Australas. J. Water Resour 1–10 (2021).

Infrastructure Australia. The Australian Infrastructure Audit 2019: An Assessment of Australia’s Future Infrastructure Needs . (2019).

Productivity Commission. National Water Reform 2020 . www.pc.gov.au (2021).

Hall, N. L., Creamer, S., Anders, W., Slatyer, A. & Hill, P. S. Water and health interlinkages of the sustainable development goals in remote Indigenous Australia. npj Clean Water 3 , 10 (2020).

Article   Google Scholar  

Maloney, M. et al. 2019 Citizens’ Inquiry into the Health of the Barka / Darling River and Menindee Lakes . https://tribunal.org.au/wp-content/uploads/2020/10/2019CitizensInquiry_BarkaDarlingMenindee-201017-02.pdf (2020).

Hartwig, L. D., Jackson, S., Markham, F. & Osborne, N. Water colonialism and Indigenous water justice in south-eastern Australia. International Journal of Water Resources Development https://doi.org/10.1080/07900627.2020.1868980 (2021).

The White House. The Biden-Harris Lead Pipe and Paint Action Plan. https://www.whitehouse.gov/briefing-room/statements-releases/2021/12/16/fact-sheet-the-biden-harris-lead-pipe-and-paint-action-plan/ (2021).

Office of the Parliamentary Budget Officer. Clean Water for First Nations: Is the Government Spending Enough? https://www.pbo-dpb.gc.ca/en/blog/news/RP-2122-021-M--clean-water-first-nations-is-government-spending-enough--eau-potable-premieres-nations-gouvernement-depense-t-il-assez (2021).

New Zealand Government. Government to provide support for water reforms, jobs and growth. https://www.beehive.govt.nz/release/government-provide-support-water-reforms-jobs-and-growth (2021).

Infrastructure Australia. Australian Infrastructure Audit 2019 . (2019).

Infrastructure Australia. 2021 Australian Infrastructure Plan: Reforms to meet Australia’s future infrastructure needs . (2021).

Australian Labor Party. Labor’s Plan to Future-Proof Australia’s Water Resources | Policies | Australian Labor Party. https://alp.org.au/policies/labors-plan-to-future-proof-australias-water-resources (2022).

Northern Land Council. Submission to the Productivity Commission Review of National Water Reform. (2021).

South Australian Council of Social Service. SACOSS Submission to the Productivity Commission’s National Water Reform Draft Report. (2021).

Aither/South Australian Council of Social Service. Falling through the gaps: A practical approach to improving drinking water services for regional and remote communities in South Australia . https://www.sacoss.org.au/falling-through-gaps-report , https://doi.org/10.1136/bmj.e7863 (2021).

Queensland Water Directorate. National Water Reform 2020: Productivity Commission Draft Report. (2021).

Local Government NSW. Draft LGNSW Submission on - Productivity Commission National Water Reform Draft Report . https://www.pc.gov.au/inquiries/completed/water-reform-2020/submissions (2021).

National Health and Medical Research Council (Australia). Australian Drinking Water Guidelines 6 . (2021).

Queensland Health. Public Health Regulation 2018 . (2021).

State of Victoria. Safe Drinking Water Act 2003 . (2019).

Water Corporation. Drinking Water Quality: Annual Report 2018–19 . https://doi.org/10.1016/0278-6915(93)90134-k .

Water Quality Australia. Guidelines for water quality management. https://www.waterquality.gov.au/guidelines (2021).

Australian Government. Basin Plan 2012 Compilation No. 8 . 269 (2021).

World Health Organisation. Guidelines for drinking-water quality: Fourth edition incorporating the first and second addenda . 4 (2022).

World Health Organisation. A global overview of national regulations and standards for drinking-water quality ii A global overview of national regulations and standards for drinking-water quality . https://www.who.int/publications/i/item/9789240023642 (2018).

Department of Regional Planning Manufacturing and Water. Water Quality and Reporting Guideline for a Drinking Water Service . https://www.rdmw.qld.gov.au/__data/assets/pdf_file/0008/45593/water-quality-reporting-guideline.pdf (2010).

Bureau of Meterology. National performance reports. http://www.bom.gov.au/water/npr/ (2021).

Australian Government. Reporting Platform on the Sustainable Development Goals Indicators. https://www.sdgdata.gov.au/goals/clean-water-and-sanitation/6.1.1 (2021).

Water Corporation WA. Drinking Water Quality Annual Report 2018-19 . https://www.watercorporation.com.au/-/media/WaterCorp/Documents/About-us/Our-performance/Drinking-Water-Quality/Drinking-water-quality-annual-report-2019.pdf (2019).

South Australian Water Corporation. South Australian Water Corporation Annual Report 2018-19 . https://www.sawater.com.au/__data/assets/pdf_file/0006/424662/2018-19-Annual-Report-with-financials-online-ISSN-HR.pdf (2019).

Power and Water Corporation. Drinking Water Quality Report 2019. (2019).

Urban Utilities. Drinking water quality management plan report 2018–19. (2019).

TasWater. Annual Drinking Water Quality Report 2018–19. (2019).

Icon Water. 2018-19 Drinking Water Quality Report. (2019).

NSW Health. NSW drinking water database - Water quality. https://www.health.nsw.gov.au/environment/water/Pages/drinking-water-database.aspx .

New South Wales Department of Planning Industry and Environment. LWU performance monitoring data and reports - Water in New South Wales. https://www.industry.nsw.gov.au/water/water-utilities/lwu-performance-monitoring-data (2021).

Office of the Auditor General Western Australia. Delivering Essential Services to Remote Aboriginal Communities – Follow-up . https://audit.wa.gov.au/wp-content/uploads/2021/05/Report-25_Delivering-Essential-Services-to-Remote-Aboriginal-Communities-%E2%80%93-Follow-up.pdf (2021).

Audit Office of New South Wales. Support for regional town water infrastructure: Performance audit . https://www.audit.nsw.gov.au/sites/default/files/documents/FINAL%20-%20Support%20for%20regional%20town%20water%20infrastructure.pdf (2020).

Federal Race Discrimination Commissioner. Water: A Report on the provision of water and sanitation in remote Aboriginal and Torres Strait Islander communities . (1994).

West Australian Auditor General. Delivering Essential Services to Remote Aboriginal Communities . (2015).

Green, K. D. Water 2000: a perspective on Australia’s water resources to the year 2000 . https://trove.nla.gov.au/work/18184199 (1984).

Regional Services Reform Unit. Resilient Families, Strong Communities, Key insights from consultation with remote Aboriginal communities in Western Australia . https://www.parliament.wa.gov.au/publications/tabledpapers.nsf/displaypaper/4010887a7914b1bf3330c905482581bf000764e6/$file/887.pdf (2017).

Rajapakse, J. et al. Unsafe drinking water quality in remote Western Australian Aboriginal communities. Geographical Res. 57 , 178–188 (2019).

Hall, N. L. Challenges of WASH in remote Australian Indigenous communities. J. Water, Sanitation Hyg. Dev. 9 , 429–437 (2019).

Jaravani, F. G., Massey, P. D., Judd, J., Allan, J. & Allan, N. Closing the Gap: The need to consider perceptions about drinking water in rural Aboriginal communities in NSW, Australia. Public Health Res Pract 26 , e2621616 (2016).

Jackson, M., Stewart, R. A. & Beal, C. D. Identifying and Overcoming Barriers to Collaborative Sustainable Water Governance in Remote Australian Indigenous Communities. Water 11 , 2410 (2019).

Beal, C. D., Jackson, M., Stewart, R. A., Rayment, C. & Miller, A. Identifying and understanding the drivers of high water consumption in remote Australian Aboriginal and Torres Strait Island communities. J. Clean. Prod. 172 , 2425–2434 (2018).

Horne, J. Australian water decision making: are politicians performing? Int. J. Water Resour. Dev. 36 , 462–483 (2020).

Kurmelvos, R. Company remains shtum on plans to filter Laramba’s contaminated water supply | NITV. NITV News (2021).

Kurmelovs, R. & Moore, I. ‘It makes us sick’: remote NT community wants answers about uranium in its water supply | Northern Territory | The Guardian. The Guardian (2021).

Archibald-Binge, E. Concerns over water quality in remote Queensland: “This wouldn’t be acceptable in the city” | NITV. NITV News (2018).

Richards, S. Oodnadatta residents “suffering” from poor water quality: Aboriginal Health Council. (2020).

Parke, E. WA Government urged to fix contaminated water supplies in remote Indigenous communities - ABC News. ABC News (2016).

Volkofsky, A., Pezet, L. & McConnell, S. Water donations flow as reports of bad drinking water increase in Darling River communities - ABC News. ABC News (2019).

O’Donnell, E., Jackson, S., Langton, M. & Godden, L. Racialized water governance: the ‘hydrological frontier’ in the Northern Territory, Australia. (2022) https://doi.org/10.1080/13241583.2022.2049053 .

Marshall, V. Overturning aqua nullius: Securing Aboriginal water rights | AIATSIS . (Aboriginal Studies Press, 2017).

Grealy, L. & Howey, K. Securing supply: governing drinking water in the Northern Territory. Australian Geographer 341–360 (2020) https://doi.org/10.1080/00049182.2020.1786945 .

Taylor, K. S., Moggridge, B. J. & Poelina, A. Australian Indigenous Water Policy and the impacts of the ever-changing political cycle. Aust. J. Water Resour. 20 , 132–147 (2016).

Jackson, S. Water and Indigenous rights: Mechanisms and pathways of recognition, representation, and redistribution. Wiley Interdisciplinary Reviews: Water 5 , e1314 (2018).

Coalition of Aboriginal and Torres Strait Islander Peak Organisations & Australia Governments. National Agreement on Closing the Gap . https://www.closingthegap.gov.au/sites/default/files/files/national-agreement-ctg.pdf (2020).

Jaravani, F. G. et al. Working with an aboriginal community to understand drinking water perceptions and acceptance in rural New South Wales. Int Indigenous Policy J 8 , (2017).

Beal, C. D. et al . Exploring community-based water management options for remote Australia . Final report for the Remote and Isolated Communities Essential Services Project . https://www.griffith.edu.au/__data/assets/pdf_file/0036/918918/Remote-community-water-management-Beal-et-al-2019-Final-Report-1.pdf (2019).

Bailie, R. S., Carson, B. E. & McDonald, E. L. Water supply and sanitation in remote Indigenous communities - Priorities for health development. Aust. N.Z. J. Public Health 28 , 409–414 (2004).

Thurber, K. A., Long, J., Salmon, M., Cuevas, A. G. & Lovett, R. Sugar-sweetened beverage consumption among Indigenous Australian children aged 0–3 years and association with sociodemographic, life circumstances and health factors. Public Health Nutr. 23 , 295 (2020).

Dharriwaa Elders Group & Walgett Aboriginal Medical Service. Recommendations for the Review of the National Water Initiative . https://www.sciencedirect.com/science/article/pii/S0264837719319799 (2020).

Natural Resouces Commission. Review of the Water Sharing Plan for the Barwon-Darling Unregulated and Alluvial Water Sources 2012. (2019).

Browett, H. et al. Cost Implications of Hard Water on Health Hardware in Remote Indigenous Communities in the Central Desert Region of Australia . Int. Indigenous Policy J. 3 (2012).

Australian Bureau of Statistics. 1270.0.55.005 - Australian Statistical Geography Standard (ASGS): Volume 5 - Remoteness Structure, July 2016. https://www.abs.gov.au/AUSSTATS/[email protected]/Lookup/1270.0.55.005Main+Features1July%202016?OpenDocument (2016).

RiverOfLife, M., Taylor, K. S., & Poelina, A. Living Waters, Law First: Nyikina and Mangala water governance in the Kimberley, Western Australia. Australas. J. Water Resour 25 , 40–56 (2021).

Jackson, S. & Nias, D. Watering country: Aboriginal partnerships with environmental water managers of the Murray-Darling Basin, Australia. Australas. J. Water Resour. 26 , 287–303 (2019).

Hemming, S., Rigney, D., Bignall, S., Berg, S. & Rigney, G. Indigenous nation building for environmental futures: Murrundi flows through Ngarrindjeri country. Australas. J. Water Resour. 26 , 216–235 (2019).

Moggridge, B. J. & Thompson, R. M. Cultural value of water and western water management: an Australian Indigenous perspective. Australas. J. Water Resour. 25 , 4–14 (2021).

Moggridge, B. J., Betterridge, L. & Thompson, R. M. Integrating Aboriginal cultural values into water planning: a case study from New South Wales, Australia. Australas. J. Water Resour. 26 , 273–286 (2019).

Hoverman, S. & Ayre, M. Methods and approaches to support Indigenous water planning: An example from the Tiwi Islands, Northern Territory, Australia. J. Hydrol. 474 , 47–56 (2012).

Jackson, S., Tan, P. L., Mooney, C., Hoverman, S. & White, I. Principles and guidelines for good practice in Indigenous engagement in water planning. J. Hydrol. 474 , 57–65 (2012).

Jackson, M., Stewart, R. A., Fielding, K. S., Cochrane, J. & Beal, C. D. Collaborating for Sustainable Water and Energy Management: Assessment and Categorisation of Indigenous Involvement in Remote Australian Communities. Sustainability 11 , 427 (2019). 2019, Vol. 11, Page 427 .

New South Wales Water Directorate. Submission 37 - NSW Water Directorate - National Water Reform - Public inquiry. (2021).

Natural Resource Management Ministerial Council. National Water Initiative Pricing Principles . https://www.awe.gov.au/water/policy/policy/nwi/pricing-principles (2010).

Kukutai, T. & Taylor, J. Indigenous Data Sovereignty . Indigenous Data Sovereignty (ANU Press, 2016). https://doi.org/10.22459/CAEPR38.11.2016 .

Maiam Nayri Wingara Indigenous Data Sovereignty Collective. Key Principles . https://www.maiamnayriwingara.org/key-principles (2018).

Ubaldi, B. Open Government Data: Towards Empirical Analysis of Open Government Data Initiatives . https://doi.org/10.1787/5k46bj4f03s7-en (2013).

Sherris, A. R. et al. Nitrate in Drinking Water during Pregnancy and Spontaneous Preterm Birth: A Retrospective Within-Mother Analysis in California. Environ. Health Perspect. 129 , 57001 (2021).

Article   CAS   Google Scholar  

Australian Government PFAS Taskforce. Per- and Polyfluoroalkyl Substances (PFAS): Australian information portal. https://www.pfas.gov.au/ (2021).

Environmental Protection Agency. Safe Drinking Water Information System Federal Reports Services System. https://sdwis.epa.gov/ords/sfdw_pub/f?p=108:200 (2021).

Indigenous Services Canada. Short-term drinking water advisories. https://www.sac-isc.gc.ca/eng/1562856509704/1562856530304 (2021).

Indigenous Services Canada. Ending long-term drinking water advisories. https://www.sac-isc.gc.ca/eng/1506514143353/1533317130660 (2021).

ESR Risk and Response Group. Drinking Water Online. https://www.drinkingwater.org.nz/ (2021).

Meehan, K. et al. Exposing the myths of household water insecurity in the global north: A critical review. Wiley Interdiscip. Rev.: Water 7 , e1486 (2020).

O’Gorman, M. Mental and physical health impacts of water/sanitation infrastructure in First Nations communities in Canada: An analysis of the Regional Health Survey. World Dev. 145 , 105517 (2021).

Baijius, W. & Patrick, R. J. "We Donat Drink the Water Here": The Reproduction of Undrinkable Water for First Nations in Canada. Water 11 , 1079 (2019).

Allaire, M., Wu, H. & Lall, U. National trends in drinking water quality violations. Proc Natl Acad Sci USA 115 , 2078–2083 (2018).

Meehan, K., Jurjevich, J. R., Chun, N. M. J. W. & Sherrill, J. Geographies of insecure water access and the housing–water nexus in US cities. Proc. Natl Acad. Sci. USA 117 , 28700–28707 (2020).

Wu, J., Cao, M., Tong, D., Finkelstein, Z. & Hoek, E. M. V. A critical review of point-of-use drinking water treatment in the United States. https://doi.org/10.1038/s41545-021-00128-z .

McFarlane, K. & Harris, L. M. Small systems, big challenges: Review of small drinking water system governance. Environ. Rev. 26 , 378–395 (2018).

Tortajada, C. & Biswas, A. K. Achieving universal access to clean water and sanitation in an era of water scarcity: strengthening contributions from academia. Curr. Opin. Environ. Sustainability 34 , 21–25 (2018).

Glade, S. & Ray, I. Safe drinking water for small low-income communities: the long road from violation to remediation. Environ. Res. Lett. 17 , 044008 (2022).

Daley, K., Castleden, H., Jamieson, R., Furgal, C. & Ell, L. Water systems, sanitation, and public health risks in remote communities: Inuit resident perspectives from the Canadian Arctic. Soc. Sci. Med. 135 , 124–132 (2015).

Dunn, G., Bakker, K. & Harris, L. Drinking Water Quality Guidelines across Canadian Provinces and Territories: Jurisdictional Variation in the Context of Decentralized Water Governance. Int. J. Environ. Res. Public Health 2014 11 , 4634–4651 (2014). Vol. 11, Pages 4634-4651 .

CAS   Google Scholar  

Herrera, V. Reconciling global aspirations and local realities: Challenges facing the Sustainable Development Goals for water and sanitation. World Dev. 118 , 106–117 (2019).

Mraz, A. L. et al. Why pathogens matter for meeting the united nations’ sustainable development goal 6 on safely managed water and sanitation. Water Res. 189 , 116591 (2021).

Schiff, J. Measuring the human right to water: An assessment of compliance indicators. Wiley Interdiscip. Rev.: Water 6 , e1321 (2019).

Charles, K. J., Nowicki, S. & Bartram, J. K. A framework for monitoring the safety of water services: from measurements to security. npj Clean. Water 3 , 1–6 (2020).

Boisvert, E. SA Water dealing with complaints from some Fleurieu Peninsula residents about change to tap water from Myponga Reservoir - ABC News. ABC News https://www.abc.net.au/news/2021-07-05/fleurieu-residents-complaints-about-water-change/100267414 (2021).

Uralla Shire Council. Water Quality Analysis. https://www.uralla.nsw.gov.au/Council-Services/Water-and-Sewer-Services/Water-Quality-Analysis (2021).

NSW Health. Drinking water quality and incidents - Water quality. https://www.health.nsw.gov.au/environment/water/Pages/drinking-water-quality-and-incidents.aspx (2021).

Kumpel, E. et al. From data to decisions: understanding information flows within regulatory water quality monitoring programs. npj Clean. Water 3 , 1–11 (2020).

Organisation for Economic Cooperation and Development. OECD Principles on Water Governance . https://www.oecd.org/cfe/regionaldevelopment/OECD-Principles-on-Water-Governance-en.pdf (2015).

Wyrwoll, P. R., Manero, A., Taylor, K. S., Rose, E. & Grafton, R. Q. Supporting dataset for “Measuring gaps in drinking water quality and policy in regional and remote Australia.” https://osf.io/vmxdz/?view_only=9f0608088e8143dbbbf2c350ff0e5ca1 (2022).

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Acknowledgements

The authors would like to acknowledge and thank Phan Le for his research assistance, Associate Professor Aparna Lal and Associate Professor Barry Croke for comments on an earlier version of the paper, and members of the Water Justice Hub for helpful feedback and insights at a seminar at the ANU Crawford School of Public Policy in June 2021. Any errors are our own. We acknowledge the Traditional Custodians of the lands on which this research was undertaken and their ongoing care for and connections to Country. We pay our respects to the Elders past and present. This work was supported by Australian Research Council Laureate Fellowship FL190100164 and the Australian National University’s Hilda John Endowment Fund.

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Wyrwoll, P.R., Manero, A., Taylor, K.S. et al. Measuring the gaps in drinking water quality and policy across regional and remote Australia. npj Clean Water 5 , 32 (2022). https://doi.org/10.1038/s41545-022-00174-1

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Swimming not recommended at Orchard Beach in the Bronx over water quality concerns

By nbc new york staff • published july 11, 2024 • updated on july 11, 2024 at 10:01 pm.

Bronx residents looking to cool off in the high heat and humidity should avoid swimming or wading at Orchard Beach , city officials said Thursday.

New York City emergency officials warned via social media that swimming and wading were not recommended "due to inadequate water quality."

Beach Advisory for Orchard Beach: Swimming & wading not recommended due to inadequate water quality. Info: call 311, text BEACH to 55676 or go to https://t.co/pG71ZHrqSh . Multilingual & ASL Link: https://t.co/YdKQG2psJa . — NYCEM - Notify NYC (@NotifyNYC) July 11, 2024

24/7 New York news stream: Watch NBC 4 free wherever you are

NYC Parks referred questions about the water quality advisory to the city's health department, which said in a statement that going in the water was not recommended in order to "prevent contracting a swimming-related illness."

The advisory came after a July 9 sample of the water found higher levels of enterococci, a bacteria the Health Department said "lives in the intestinal tracks of warm-blooded animals and is used as an indicator organism for evaluating beach water quality." The testing showed a bacteria count level of 145, far above the safe limit of 104 set by the state's health department.

If water is ingested, officials said the bacteria can cause urinary tract infections, blood infections and endocarditis, an inflammation of the lining of the heart's values and chambers.

Get Tri-state area news delivered to your inbox. Sign up for NBC New York's News Headlines newsletter.

Despite the advisory, there were no signs or officials seen at the beach warning of the elevated bacteria in the water.

Rats take another blow as pizza box trash cans spread throughout NYC

Jewish students at Columbia faced hostile environment during pro-Palestinian protests: report

It was not immediately clear how long the advisory would last, as it depended on bacteria levels in future samples. The NYC Health Department said that beaches can be classified into three categories — open, advisory or closed — based on environmental or public health factors.

The advisory comes after three Long Island beaches in Amityville, Copiague and Bayport were closed with elevated bacteria levels as well, likely caused by runoff from recent rains.

For latest updates on advisories and closings, the city has an interactive map available on their website .

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Water-Quality Trends

Surface-water trends, changes in the quality of u.s. groundwater, water-quality trends from lake cores, trends in sediment-associated contaminants, access data for water-quality trends in u.s. streams and rivers, 110 stream and river sites with long-term, consistent data on water quality.

• Publications

Is water quality getting better or worse?  Answering this deceptively simple question has been a fundamental objective of the USGS National Water-Quality Assessment Project’s research. Learn about trends in contaminants in the nation’s streams and rivers, trends in contaminants that collect in the bed sediment of streams and lakes, and changes in the quality of the nation’s groundwater.

Changes in Water Quality of U.S. Rivers

Human activities have markedly changed the water quality of rivers in the past few decades according to a new study by the U.S. Geological Survey—concentrations of some water-quality constituents have increased while others have decreased.

Suspended Sediment in Streams Decreasing

Concentrations of suspended sediment in many streams are decreasing, reports a new study by the USGS National Water Quality Program. Changes in land management are largely responsible.

In 1991, Congress established the National Water-Quality Assessment (NAWQA) Project to address where, when, why, and how the Nation's water quality has changed, or is likely to change in the future, in response to human activities and natural factors. In response, the NAWQA Project developed multi-pronged approaches to characterize trends in diverse contaminants in the Nation’s streams, rivers, bed sediment, and groundwater.

Trends in Contaminant Concentrations and Loads in the Nation’s Streams and Rivers

The  NAWQA Project, other USGS programs, and other Federal, State, and local agencies have collected years of water-quality data to support their assessments of changing water-quality conditions. For the first time, all of these data have been combined to support the most comprehensive assessment conducted to date of water-quality trends in the United States. Collectively, these data provide insight into how natural features and human activities have contributed to water-quality changes over time in Nation's streams and rivers. Data are updated annually. The online Water-Quality Trends mapping tool allows users to visualize trends in water chemistry (nutrients, pesticides, sediment, carbon, and salinity) and aquatic ecology (fish, invertebrates, and algae)

Trends in Sediment-Associated Contaminants

Many contaminants adhere, or sorb, to sediment, so that standard water-quality sampling and analysis is often unable to detect changes in their concentrations over time.  Sediment-associated contaminants include legacy contaminants, such as DDT and PCBs, and contaminants currently released into the environment, such as the pesticide bifenthrin and polycyclic aromatic hydrocarbons (PAHs).  An alternative approach to determine trends in concentrations of these contaminants is the use of sediment cores collected from lakes and reservoirs.

Changes in Groundwater Quality

USGS scientists are characterizing groundwater quality in principal aquifers, the primary source of the Nation's groundwater used for drinking.  Users can access an online tool to see how concentrations of pesticides, nutrients, metals, and organic contaminants in groundwater are changing during decadal periods across the Nation, and see in real time how chemical properties of groundwater at some sites are fluctuating.

Follow the links below to learn more about the quality of the Nation’s streams, rivers, and groundwater and how it’s changing.

National Water-Quality Assessment (NAWQA)

Water Quality in the Nation’s Streams and Rivers – Current Conditions and Long-Term Trends

Groundwater Quality—Current Conditions and Changes Through Time

Access the data releases and tools relating to water-quality trends below.  Explore more data releases on groundwater quality at ScienceBase.

Changes in anthropogenic influences on streams and rivers in the conterminous U.S. over the last 40 years, derived for 16 data themes

Water-quality trends and trend component estimates for the nation's rivers and streams using weighted regressions on time, discharge, and season (wrtds) models and generalized flow normalization, 1972-2012, data from decadal change in groundwater quality web site, 1988-2014, version 2.0, watershed characteristics for study sites of the u.s. geological surveys national water quality programs surface water trends project, pesticide concentration and streamflow datasets used to evaluate pesticide trends in the nations rivers and streams, 1992-2012, classification of chloride-to-sulfate mass ratio for u.s. groundwater with respect to the potential to promote galvanic corrosion of lead, 1991-2015; water well data and characteristic values for states.

The links below provide access to some of the most recent publications describing how the quality of the nation’s surface water and groundwater is changing.

Water-quality trends in US rivers: Exploring effects from streamflow trends and changes in watershed management

Landscape drivers of dynamic change in water quality of us rivers, changing suspended sediment in united states rivers and streams: linking sediment trends to changes in land use/cover, hydrology and climate, causal factors for pesticide trends in streams of the united states: atrazine and deethylatrazine, network controls on mean and variance of nitrate loads from the mississippi river to the gulf of mexico, projected urban growth in the southeastern usa puts small streams at risk, variable impacts of contemporary versus legacy agricultural phosphorus on us river water quality, historical changes in fish communities in urban streams of the southeastern u.s. and the relative importance of water-quality stressors, regional patterns of anthropogenic influences on streams and rivers in the conterminous united states, from the early 1970s to 2012, assessing water-quality changes in u.s. rivers at multiple geographic scales using results from probabilistic and targeted monitoring, recent trends in nutrient and sediment loading to coastal areas of the conterminous u.s.: insights and global context, effects of antecedent streamflow and sample timing on trend assessments of fish, invertebrate, and diatom communities, water-quality changes in the nation's streams and rivers.

This mapper provides results from the largest-ever assessment of water quality changes in the Nation's streams and rivers. More than 185 million water-quality records from over 600 Federal, State, Tribal, and local organizations were screened as part of this assessment. 

Below are news stories associated with this project.

Nitrate loads entering the Gulf of Mexico have not changed despite reductions at local scales

Reducing delivery of nitrate to the Gulf of Mexico is critical to decreasing the size of the “dead zone”—an area of hypoxia, or low dissolved oxygen...

Sampling design brings insights to changing stream quality

How does the choice of sampling approach affect our perception of whether water quality in streams and rivers has changed over time? A new joint U.S ...

USGS Online Mapper Provides a Decadal Look at Groundwater Quality

A first of its kind, national assessment of an unseen, valuable resource used by millions of people.

U.S. Rivers Show Few Signs of Improvement from Historic Nitrate Increases

During 1945 to 1980, nitrate levels in large U.S. rivers increased up to fivefold in intensively managed agricultural areas of the Midwest, according...

Trends in River Pesticide Levels Echo Pesticide Use

Usgs release: large rivers in u.s. are becoming less acidic.

Several large rivers in the U.S. are less acidic now, due to decreasing acidic inputs, such as industrial waste, acid mine drainage, and atmospheric...

Poor water quality in the Seine forces 1-day postponement of Paralympic triathlon events

Organizers confirm that all 11 medal events will take place monday.

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Paralympic triathlon competitions in Paris scheduled for Sunday were postponed for a day because of concerns about water quality in the Seine River after heavy rainfall, organizers said.

The 11 para triathlon events are now scheduled for Monday, the Paris 2024 organizing committee and World Triathlon said in a joint statement.

Rainstorms hit the French capital Friday and Saturday. Heavy rains cause wastewater and runoff to flow into the river, leading to a rise in bacteria levels including E. Coli.

• Seine water quality issues resurface for triathletes at Paralympics

While organizers awaited new test results, Rabadan said "the trend is actually positive to being able to have the competition tomorrow morning."

Late Sunday night, organizers confirmed the races would go ahead Monday, saying in a statement that new water testing results and monitoring "indicate that water quality continues to improve and will be within the World Triathlon thresholds on race day."

This was the second scheduled change for the para triathlon events. They had initially been scheduled to take place over two days, Sunday and Monday, but were moved to Sunday because of rain forecasts.

• DAY 1 ROUNDUP Canadian swimmer Aurélie Rivard wins bronze medal to kick off Paris Paralympics

The men's individual triathlon event during the Paris Olympics was delayed and several test swims were cancelled because of high E. Coli levels after rainstorms.

Lazreg Benel-Hadj, vice president of the French Swimming Federation, said that while some of the 53 athletes who took part in Olympic swimming competitions in the Seine fell ill afterward, none of those illnesses "was linked to the water in the Seine." 

Rabadan reiterated that athletic events in the river would continue past the Paralympics.

"Yes, for sure, we will continue," he said. "We'll continue to have competition in the river. So many reasons for that. First one because athletes are happy with that, and second one because the quality of water will permit it in the future. So we will keep going on that way. And that's a massive legacy of the games."

Related Stories

• Trio of German swimmers fall ill after Olympic open water races in the Seine
• Kate O'Brien captures track cycling bronze for Canada's 1st medal of Paris Paralympics
• Paris Paralympics declared open amid grand spectacle at Place de la Concorde
• CBC Explains Explaining impairment classification at the Paralympic Games
• Olympic marathon swim test run cancelled over water quality concerns for Seine River

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Paralympic triathlon events are postponed for a day because of poor water quality in the Seine River

Aptopix paris paralympics triathlon water quality.

PARIS (AP) — Paralympic triathlon competitions in Paris scheduled for Sunday were postponed for a day because of concerns about water quality in the Seine River after heavy rainfall, organizers said.

The 11 para triathlon events are now scheduled for Monday, the Paris 2024 organizing committee and World Triathlon said in a joint statement.

Rainstorms hit the French capital Friday and Saturday. Heavy rains cause wastewater and runoff to flow into the river, leading to a rise in bacteria levels including E. Coli.

″It rained a lot Friday and then it also rained Saturday. So the international federation and the organizing committee ... out of a principle of precaution decided to delay all of the events for a day,” Paris Deputy Mayor Pierre Rabadan told reporters.

While organizers awaited new test results, Rabadan said "the trend is actually positive to being able to have the competition tomorrow morning.”

Late Sunday night, organizers confirmed the races would go ahead Monday, saying in a statement that new water testing results and monitoring ‘’indicate that water quality continues to improve and will be within the World Triathlon thresholds on race day.''

This was the second scheduled change for the para triathlon events. They had initially been scheduled to take place over two days, Sunday and Monday, but were moved to Sunday because of rain forecasts.

The disruption is another hiccup for the city’s efforts to clean up the river for future public swimming, one of Paris’ most ambitious promises ahead of hosting the Olympics and Paralympics this summer. The men's individual triathlon event during the Paris Olympics was delayed and several test swims were canceled because of high E. coli levels after rainstorms.

Lazreg Benel-Hadj, vice president of the French Swimming Federation, said that while some of the 53 athletes who took part in Olympic swimming competitions in the Seine fell ill afterward , none of those illnesses ″was linked to the water in the Seine.″

Rabadan reiterated that athletic events in the river would continue past the Paralympics.

“Yes, for sure, we will continue,” he said. “We’ll continue to have competition in the river. So many reasons for that. First one because athletes are happy with that, and second one because the quality of water will permit it in the future. So we will keep going on that way. And that’s a massive legacy of the games.”

AP Paralympics https://apnews.com/hub/paralympic-games