Water Pollution

Sarah Simon

24 min Read Time | July 2nd 2023

Key Takeaways

This topic focuses solely on a company’s impact on aquatic ecosystems and biodiversity through water pollution. This involves, but is not limited to, the leakage of toxic chemicals/sludge, food waste, metals, fertilizers, pesticides, etc., in water bodies that can have adverse environmental impacts.

It is essential to assess what pollutants are released from the company and where, even though the contamination can spread far from the original polluting source.

Only write about companies for which at least one of the discharged pollutants is above the threshold limits listed in the table of thresholds we provided for you.

What is it?

Water pollution occurs when harmful organic or inorganic substances, in a higher concentration than the natural ones, are found in lakes, rivers, groundwater, oceans, and other water bodies; ultimately degrading the water quality and representing a threat to human health and the aquatic ecosystems.

When it comes to water, companies can have different kinds of impacts. Their consumption can cause water reserve depletion, their wastewater and pollutants can affect human health and make water unsafe for drinking, swimming, fishing, and other activities. Further, companies, wastewater, and pollutants can also negatively impact aquatic ecosystems and biodiversity.

The topic 'Water Pollution' treats only the environmental effects of companies’ wastewater and pollutants over aquatic ecosystems and biodiversity. Impacts over water depletion and human health are treated in different topics.

This topic specifically looks at a company’s impact on water pollution regarding specific water bodies, including surface water and groundwater (which eventually seeps into rivers, lakes, and oceans).

A company can cause water pollution not only through their wastewater, but also through their disposal of toxic chemicals, food waste products, toxic sludge, leakage of metals, oil spills, fertilizers, pesticides, animal waste, excess nutrients, and even their effect on the water temperature, known as heat pollution.

Categories of water pollution

  • Groundwater
  • Surface water
  • Ocean water
  • Point source
  • Non-point source
  • Transboundary

⚠️ Caution!

  • As the topic of ‘Water Pollution’ is on the effects on life below water, make sure to not include other impacts to avoid overlap. For instance, operational water consumption (depletion, consumption, withdrawal), and impacts on human health are treated in separate topics.

  • Always check which topic has been covered on the platform and determine if the topic you wish to write about is significant enough to stand on its own.

  • This topic is only relevant if the analysis deals with how the wastewater is polluting water supplies and harming ecosystems and biodiversity, or entering water bodies.

  • The volume of water discharged alone is insufficient to assess the impact of wastewater. It is not relevant unless there is some significant negative impact.





✅ SDG: 14

✅ Category: Processes or Products


  • Alcoholic Beverages
  • Biotechnology & Pharmaceuticals
  • Construction Materials
  • Containers & Packaging
  • Electric Utilities & Power Generators
  • Electrical & Electronic Equipment
  • Household & Personal Products
  • Pulp & Paper Products


  • Agricultural Products
  • Chemicals
  • Coal Operations
  • Cruise Lines
  • Iron & Steel Producers
  • Marine Transportation
  • Meat, Poultry & Dairy
  • Metals & Mining
  • Oil & Gas - Exploration & Production
  • Oil & Gas - Midstream
  • Oil & Gas - Refining & Marketing
  • Oil & Gas - Services
  • Waste Management

✅ ILG: Healthy Ecosystems

Impact assessment

General guidelines and information about the topic:

  • Analyses treating this topic should address a company’s wastewater generation and other impacts of discharge or spills on water resources having negative environmental impacts.
  • The analysis should assess where and how much the company is responsible for the pollution of local water bodies.
  • It should also address the management of wastewater treatments and discharge, including groundwater and aquifer pollution.
  • The volume of water discharged alone is insufficient to assess the impact of wastewater. It is not relevant unless there is some negative impact.
  • Avoid writing a list of one example after the other. Rather, focus on the most recent year in which you can find 1-2 significant examples of this occurring and then look at the historical trend over time.

Think about the following questions:

  • What impact does this pollution have?
  • How is the local ecosystem affected?
  • Is this a recurring issue?
  • Has the company's behaviour changed in regards to this? If yes, you will need to show that the impact is long-lasting; otherwise, there is no current impact.


The introduction should discuss the issue of water pollution and how the industry (in which the company is) is contributing to this overall problem. Include absolute values when possible and ensure the information is recent and relevant.

Points to discuss:

  • Why is water quality and preservation important?

  • What are the consequences of water pollution on the environment?

  • Industry-specific data: is this industry known for water pollution? How so? Why?

  • Describe the environmental consequences stemming from the main pollutants that will be discussed in the core. How are they harmful? Why? What is the impact?

  • How long will the impact last?

Core Analysis

The core of the analysis should uncover the company's quantifiable impact on water pollution. Here, the analysis should prove that the pollutants released in wastewater by the company are indeed above safety limits.

Therefore, the impact is tangible and causes water quality degradation, and aquatic loss/biodiversity loss, rendering water bodies toxic for life.

Points to discuss:

  • The activities undertaken by the company that results in wastewater discharged

  • How much water is discharged in the latest available year

  • If available, where did it discharge its wastewater?

  • Did it treat its wastewater? (include %, if not we assume it did not treat its wastewater).

  • The list of all pollutants it discharged in water systems (look at the permissible thresholds in the document below)

  • Are those pollutants effectively above safety limits (disclose figures in mg/l = concentrations)
    • In some cases, companies may discharge multiple pollutants. If only one is above safety limits, we can publish the analysis. In such a case, we should have a comprehensive analysis of how this pollutant is endangering water systems (linked to the introduction). The others can be mentioned too.

  • How do such pollutants affect life below water? What sort of environmental impacts can be felt? If possible, include direct impact data.

  • Is this a recurring issue?

  • Does the company have any remediation measures?

When assessing a company’s responsibility for polluting a local water body (especially large-scale ones in which multiple companies are involved), it is imperative that you show the facts and figures to prove such links and estimates on how responsible the specific company is.

Examples of evidence include court rulings, scientific reports, company reports, violations/fines, etc.

What is also helpful is to provide information on how responsible the industry is for water pollution as well as providing the market share of the company in that given industry. This in turn shows how large and influential the company is in regards to this issue.
  • Has the company contributed to the highest levels of pollution in a given region/area?
  • Is it one of how many of the highest documented levels of contamination?

What is the impact on the aquatic ecosystem? (examples)

  • Has there been a decline of a local species population and/or other indicators of biodiversity loss?
  • Has there been a change in living organisms' behaviours or growth?
  • Are there scientific claims if the location is considered a “dead zone”, “contaminated” or any other scientific assessments, lab work, and research?

Help readers rate the company’s impact by linking studies to the chemical/element discharged by the company and making comparisons with competitors and industry average, when relevant.

Concentration Calculation: How to assess if a company discharges pollutants that are above safety limits

You need:

  • The total amount of water discharged by a company in cubic meters (m3) and litres (L/l)

  • List of all pollutants discharged in wastewater (usually reported in tonnes)


  • A company discharged: 85 Mn m3 of water

  • We convert the discharged water from m3 to L → 85Bn Liters [L/l]

→ Converter: https://www.to-convert.com/en/volume/convert-m3-to-liter.php

  • The company reports the release of: 2,000 tonnes (t) of BOD

  • We convert tonnes of the pollutant to milligram (mg) → 2Tr mg

→ Converter: http://www.kylesconverter.com/mass/tonnes-to-milligrams

  • Finally, divide the mg amount of the pollutant by the liter amount of water discharged by the company. This is to obtain a mg per liter concentration

→ 2Tr mg of BOD / 85Bn litres of water discharged by X company = 23.5mg/l

  • Is 23.5mg/l above the permissible safety limit? Yes or no? (consult the document below to see the list of pollutants and their concentration)

Please note that we have decided not to base the impact of water pollution on federal limits. This decision has been taken as each country has different limits, rendering it more political than scientific.

Points to consider:

  1. The topic does not include the company's water consumption. This topic is covered under "Operational Water Consumption".

  2. When assessing a company’s responsibility for polluting a local water body in which multiple companies are involved, it is imperative to show the facts to prove such a link and estimate how responsible the specific company is. Examples of evidence include court rulings, scientific reports, company reports, violations/fines, etc.

  3. When assessing the impact on the aquatic ecosystem, some information to include is indicators of biodiversity loss, changes in living organisms' behavior or growth, scientific claims if the location is considered a “dead zone”, “contaminated” or any other scientific assessments, lab work, and research.

  4. Micro-beads, micro-plastics, micro-fibers, and similar end-of-life products should be treated as Product End-of-Life Waste instead of under Water Pollution.

Common mistakes:

  • Including only spills when the company also discloses other pollutants that are above the limits. I.e., not being comprehensive enough

  • Mixing other types of environmental impacts (e.g toxic waste)

  • Mixing with impacts on humans health

Thresholds for Water Pollutants

To ensure consistency across the platform, the Impaakt team collected data on the most frequently encountered pollutants discharged by companies from different industries.

You will find thresholds for the most common water pollutants (table 1.1) with a brief description of their relevance, as well as thresholds for less common water pollutants reported on (table 1.2).

Whenever possible, we based these thresholds on the EU Water Framework Directive (WFD). We chose to adopt the WFD because it brings a comprehensive set of directives and parameters aimed to improve water quality as a whole. We esteem it to be more stringent than other policies, such as the US Clean Water Act (CWA) that focuses on reducing surface pollution from some specific sources. For pollutants that were not present in the WFD, we used reliable scientific works to establish the thresholds.

This means that regardless of where the company operates we will benchmark the pollutants’ concentrations (mg/l) to EU permissible thresholds.

In the two tables, you will find an easily accessible figure describing the permissible concentration supported by a source the figure has been taken from, including the page number. You can use the source and page number in the chart to cite your work.

Ratings: We can accept analyses when at least one of the pollutants is above the thresholds listed below. Remember that even though the analysis remains negative (impact value), the scale will be on the lower end (impact scale).

To ensure consistency across the platform, make sure all of the pollutants are measured using the same metric (mg/L).

If you encounter a pollutant which is not already in this table, please refer to the main WHO source mentioned in the tables below to find the threshold limit. If it is not in the WHO source, you can also propose another trustworthy source with stringent guidelines in your analysis.

⚠️ Caution - There are three possible case scenarios:

1) The company reports and discharges pollutants that can be found in the chart below:

  • This is the ideal scenario that will apply to most of the cases. We proceed as instructed above by consulting the chart and the permissible thresholds for pollutant(s).

2) The company reports on pollutants that are not listed in the chart (2 routes):

a. You can look online for permissible thresholds for the undisclosed pollutant, making sure the permissible limit pertains to the EU.

6. The pollutant is not on the list and the permissible limit cannot be found, then the analysis cannot be published unless at least one pollutant can be covered and treated as per our standards.

3) It is not possible to benchmark a pollutant to EU standards as there is no customary guidance on it:

  • We can publish in this scenario only if the water pollution case is reported and verified by studies confirming that the release of the pollutant was indeed toxic for water systems and the impact was measured by the authorities.

1.1 Most common pollutants reported on:

*If the WHO source for Chapter 3 on Water is not working, you can find it saved in our Drive.


Threshold (mg/l)

Source; Page Number


Biological Oxygen Demand (BOD)


Source; 20

The Biological Oxygen Demand (BOD) represents the amount of oxygen consumed by aquatic microorganism for breaking down organic matter. The highest the BOD value, the more polluted is the water. While lower BOD values indicate less polluted water.


Chemical Oxygen Demand (COD)


Source; 25

The Chemical Oxygen Demand (COD) represents the amount of oxygen needed to oxidise the organic matter present in waterbody. Higher levels of COD indicate more polluted water, while lower values indicate cleaner water.


Phosphorus (P)


Source; 23

Phosphorus (P) is a common ingredient of crop fertilizers and manure. However, plants can absorb only a certain amount of P. Thus, the surplus amount of P accumulates in the soil or is washed up to waterbodies. The excess of P in water can lead to eutrophication.


Total Nitrogen (N)*


Source; 67

Similarly to P, Nitrogen (N) is commonly used in crop fertilizers and manure. An excess of N can lead to soil and water pollution. It can also lead to the eutrophication of waterbodies.


Dissolved Oxygen (DO)

< 9.0

Source; 19

Dissolved oxygen (DO) is the amount of gaseous oxygen present in water and available to aquatic organisms. Low levels of DO indicate polluted water and an excess of organic matter


*Here we are considering the sum of all types of N (e.g. nitrate, nitrite, etc). So, you should use this value when the company discloses only the “Nitrogen” concentration (i.e., without any specification). If the company mentions a specific form of N (e.g., the concentration of Nitrate-N, Nitrate, Nitrite-N, etc.), please refer to the next table.

1.2 Less common pollutants reported on:


Threshold (mg/l)

Source; Page Number

Total Suspended Solids (TSS)


Pages: 9, 10, 19

Total Dissolved Solids (TDS)


Page: 160




Ammoniacal Nitrogen


Pages: 19-20



Page: 20



Page: 20






Page: 20









Page: 20






Page: 20



Page: 20

Nitrate (NO3)



Nitrite (NO2)


Page: 19

Nitrate Nitrogen (NO3-N)


Page: 19

Oil & grease (n hexane extract)


Page: 3



Page: 20

Sulfide (S2)


Page: 4



Page: 3



Page: 20

Additional Information on Assessing Pollution

The concentration of chemicals, which is commonly reported in wastewater samples as mg/L or ppm, shows the volume of a substance (i.e., mg of BOD) present in a known volume of wastewater (i.e., in 1 Liter).

Concentration is, therefore, a relative number and does not tell us how much there is of the chemical/substance, such as the mass or the weight that is being discharged.

The absolute number is referred to as loading. Loadings are commonly reported as kg per day (kg/d).

BOD stands for Biochemical Oxygen Demand and is defined as “the amount of dissolved oxygen needed by aerobic biological organisms to break down organic material present in a given water sample at a certain temperature over a specific time period.”

Other chemical measurements include:

  • COD (Chemical Oxygen Demand)
  • TOC (Total Organic Carbon)
  • O&G (Oil and Grease)

To show the scale of the chemical concentration, it is valuable to state what the measurements of these chemicals are in a healthy body of water.

There are 4 main categories to measure wastewater quality:

1 - Organics

"A determination of the concentration of carbon-based (i.e., organic) compounds aimed at establishing the relative 'strength' of wastewater."

For example:

  • Biochemical Oxygen Demand (BOD)
  • Chemical Oxygen Demand (COD)
  • Total Organic Carbon (TOC)
  • Oil and Grease (O&G)
2 - Solids

"A measurement of the concentration of particulate solids that can dissolve or suspend in wastewater."

For example:

  • Total Solids (TS)
  • Total Suspended Solids (TSS) - According to the WHO, suspended solids are non-filterable residues. These residues can consist of different particles such as clay, silt, organic or inorganic compounds, microorganisms, and others.
  • Total Dissolved Solids (TDS) - According to the WHO, dissolved solids are filterable residues.
  • Total Volatile Solids
  • Total Fixed Solids (TFS)

3 - Nutrients

"A measurement of the concentration of targeted nutrients that can contribute to the acceleration of eutrophication."

For example:

  • Targeted nutrients: nitrogen and phosphorus
  • Acceleration of eutrophication: natural ageing of water bodies and others
4 - Physical Properties and Other Impact Parameters

"Analytical tests designed to measure a varied group of constituents directly impact wastewater treatability."

For example:

  • Temperature
  • Colour
  • pH
  • Turbidity
  • Odour


Data Points

Values we are looking for are:

  • Total water discharged

  • Amount of water discharge that was treated (if any)

  • Where and when was the water discharged?

  • Specific pollutants released in water discharge, i.e., BOD, COD, Phosphorous, etc.

  • The pollutants’ concentrations (mg/L), calculated out of the un-treated water discharge

  • Benchmark of the concentrations to the WHO/EU permissible limits as outlined in the How-to-guide

  • Any other polluting substances spilled, i.e., oil spills, etc.

  • Fully-fledged cases of reported water pollution by X company + impact data on aquatic ecosystems

  • The persistence of the impact

Some definitions:

  • Disclosed: When the data is directly disclosed by the company, i.e., we did not do any calculations/estimations to obtain the figure.

  • Estimated: When we have calculated the figure.

  • Complete: When the data represents 100% of the company’s operations.

  • Partial: When the data is given for only a portion of its operations (not 100%).


  • If the analysis does not disclose oil spills and direct impact data, it will be publishable only if at least one of the pollutants were released in concentrations above the permissible limits.

  • We want to have homogenous and comparable units. Therefore, you must use:

→ cubic meters (m3) for wastewater amounts

→ mg/L for concentrations

→ tonnes or m3 for spills

Data Points:

  • total wastewater discharged
  • total mass of all the pollutants
  • total concentration of BOD
  • total mass of BOD
  • total concentration of COD
  • total mass of COD
  • total concentration of TDS and/or TSS
  • total mass of of TDS and/or TSS
  • total concentration of Phosphorus
  • total mass of Phosphorus
  • total concentration of Nitrogen
  • total mass of Nitrogen
  • total concentration of Hydrocarbons and derivatives: Benzene, Hexane, Polychlorinated biphenyls (PCBs), Anthracene, Benzene, Fluoranthene, Naphthalene, Polyaromatic hydrocarbons (PAH), etc.
  • total mass of Hydrocarbons and derivatives
  • total concentration of Potentially Toxic Elements: Nickel (Ni), Lead (Pb), Cadmium (Cd), Molybdenum (Mo), Cobalt (Co), Chromium (Cr), Arsenic (As), Copper (Cu), Zinc (Zn), Iron (Fe), Manganese (Mn), Cyanide (CN), Mercury (Hg), etc.
  • total mass of Potentially Toxic Elements
  • total concentration of Halogen-containing substances: Adsorbable Organic Halides (AOX), PFOA, PFAS, Fluorine compounds, Iodine, Brominated diphenylethers, C10-13-chloroalkanes, Derivatives of Perfluorooctane sulfonic acid, Dichloroethane
    Dichloromethane, Dioxin-like polychlorinated biphenyls (PCB-DL), Hexabromocyclododecanes (HBCDD), Hexachlorobenzene, Hexachlorobutadiene, Hexachlorocyclohexane, Pentachlorobenzene, Perfluorooctane sulfonic acid (PFOS), Polychlorinated dibenzo-p-dioxins (PCDDs), Polychlorinated dibenzofurans (PCDFs), Trichlorobenzenes, TrichloromethaneChloroform, etc.
  • total mass of Halogen-containing substances
  • total concentration of pesticides (including herbicides/insecticides/anti-fouling biocides): Aclonifen, Alachlor, Atrazine, Bifenox, Diuron, Isoproturon, Simazine, Terbutryn, Trifluralin, Chlorfenvinphos, Chlorpyrifos, Cypermethrin, Dichlorvos, Endosulfan, Heptachlor, 
    Heptachlor epoxide, Dicofol, Pentachlorophenol, Quinoxyfen, Cybutryne, Tributyltin compounds, etc.
  • total mass of pesticides/herbicides/insecticides
  • treats the water discharged: Yes/No
  • % of wastewater treated
  • presence of a fine: Yes/No
  • oil spill incident
  • number of oil spills
  • total volume of spills
  • others* -> should be included in the total, either of the mass of the concentration: PRTR, Uranium, Mining waste, Tailings, Sulphate, Gasoline, 1,4-dioxane, Solid waste, Phenytoin, Boron, DEHPDi(2-ethylhexyl)phthalate, Dioxins and dioxin-like compounds, Nonylphenols, Octylphenols, Tetramethylbutyl-phenol, etc.

*NB: The data point "total concentration of all the pollutants" is the sum of the concentration of all pollutants released, including the "other" pollutants



Industry-Specific Information


Agriculture is the number one source of contamination in rivers and streams. When it rains, fertilizers, pesticides, and animal waste containing not only harmful bacteria and viruses but also excessive amounts of nutrients (nitrogen, phosphorus) can leach into local water bodies. This leads to algal bloom events and biodiversity loss.

It is important to mention how many farms the company has, specifying the regions, and linking cases of algal blooms/contaminated water bodies that the company is responsible for.


Around 150 liters of water is used per kilogram of fabric to carry out the process of dyeing. Harmful chemicals are often released into the environment through unfiltered wastewater. To address this topic and not overlap other topics on our platform, there must be clear links to the company polluting a local water body.

Mining/nuclear power plants/weapon production

Radioactive waste is “any pollution that emits radiation beyond what is naturally released by the environment.” Since radioactive waste can stay in the environment for thousands of years, it severely threatens surface water, groundwater, and marine resources.

To address this issue properly, provide information on where the radioactive waste was disposed of and how this impacts the local water body. Be sure to include the long-lasting effects as well as clear links that the company caused this issue.


1. Check if the assigned analysis has more recent data (we require the latest data available)

NO: do not refresh the analysis and please report it 

YES: Move to step 2

2. Update the analysis following our Important Metrics & Standards

3. Check if all relevant water pollution-related impacts are being discussed in the body

4. Add any missing data that is relevant and was not previously captured

5. Check the intro: Is it up to standard? Are sources working? Is data current and relevant?

YES: do not refresh the introduction

NO: move to step 6

6. Check if the concentrations and masses are correct and up to standards

7. Fix the conclusion, if needed.

8. Update the data points as per the available data.

9. Fix the Headline.


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