Constitutional law sets out the principles by which a state is governed and the relationship between the various branches of government. It is often set out in a constitution or charter which defines the roles and powers of government and the basic rights of people. Many modern constitutions include the right to a clean and healthy environment, and therefore states may be obliged to tackle freshwater pollution on this basis. This type of law overlaps closely with Human Rights law.
Environmental laws protect the environment and how humans interact with the environment. They can cover pollution, as well as protecting natural resources such as forests, water and wildlife. They include the body of laws which protect living things (including humans) from the harm that human activity can cause either directly or to the habitats on which living things depend. Environmental law is often a system of checks and balances, seeking to regulate the harms caused by industries in a way that allows for some protection of the environment. It is often regulatory in nature, meaning it may set pollution limits or prohibit polluting activity without necessary permits, licences or corresponding mitigation measures. Individuals may therefore challenge the behaviour of polluters for their failure to comply with environmental law. Alternatively, they may challenge the granting of a licence/ permit to a polluter on the basis that it was granted wrongfully due to a procedural or substantive error.
There are a few fundamental principles which underpin environmental laws around the world. It is useful to understand these when considering how to hold polluters and authorities accountable, although these principles are not laws you can directly rely on.
The precautionary principle is a fundamental principle of public international law. It is an environmental law which essentially says that, if something might cause irreversible damage, even if you don’t have scientific certainty that it will definitely cause irreversible damage, then you should err on the side of caution and protect the environment. The concept is stated in the principle 15 UN Rio Declaration 1992, which says:
“In order to protect the environment, the precautionary approach shall be widely applied by States according to their capabilities. Where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation.”
To what extent you can rely on the precautionary principle in domestic law depends on its implementation and whether it has been implemented into domestic law.
The Polluter Pays principle in Environmental law is found in principle 16 of the Rio Declaration 1992, and says that polluters should in principle bear the cost of pollution. Both the polluter pays and the precautionary principle are widely found in international and domestic law.
Example
These laws regulate public bodies or semi-private water companies responsible for providing clean water for domestic consumption. These laws will set certain water quality standards for public bodies to maintain, as well as the responsibilities they have towards citizens and consumers.
An environmental impact assessment (EIA) is a critical aspect of environmental law which requires that the harms are assessed before industrial developments are carried out. There is no universal requirement on what an EIA requires, but public bodies are often required to carry out and review environmental impact assessments before approving projects by polluting industries.
EIA typically requires an analysis of the consequences of any plan, policy, program or decision on the environment. These assessments should play a key factor in deciding whether any potentially polluting actions should be allowed to take place and, if so, what mitigation measures must be taken to prevent harm. The assessments are fundamental to ensuring compliance with the precautionary principle and polluter pays principles. Public law will determine the factors public environmental bodies have to consider when issuing and reviewing assessments, and therefore the conditions for either permitting or refusing to allow pollution to take place.
General comment No. 26 (2023) on children’s rights and the environment, with a special focus on climate change, of the UN Convention on the Rights of the Child (UNCRC), advises that child impact assessments should also be undertaken and can be done as part of an environmental impact assessment,
Whether child rights impact assessments are included within the framework of an environmental or integrated impact assessment, or carried out as a standalone assessment, they should incorporate a special regard for the differential impact of environmental decisions on children, in particular young children and other groups of children most at risk, as measured against all relevant rights under the Convention, including short-, medium- and long-term, combined and irreversible impacts, interactive and cumulative impacts and impacts in the different stages of childhood. For example, States that have substantial fossil fuel industries should assess the social and economic impact on children of their related decisions.
In reality, the environmental impact assessments or environmental statements submitted by developers are usually produced by consultants for the purpose of serving corporate interests rather than objectively written. It is a good strategy to scrutinise any EIA and identify environmental concerns or gaps, and raise these to the authorities before the project is started. If you are aware of a plan for a development, you can try to challenge the environmental impact assessment by saying that it is not sufficiently comprehensive, or inaccurate. This may not always work, but it is a low cost method of trying to prevent environmental harm. You can also engage your own experts to counter the developer’s reports.
General comment No. 26 (2023) on children’s rights and the environment, with a special focus on climate change, of the UN Convention on the Rights of the Child (UNCRC), mandates child impact assessments under para 75:
All proposed environment-related legislation, policies, projects, regulations, budgets and decisions, and those already in force, require vigorous children’s rights impact assessments, in accordance with article 3 (1) of the Convention. States should require the assessment, both before and after implementation, of the possible direct and indirect impact on the environment and climate, including the transboundary, cumulative, and both production and consumption effects, on the enjoyment of children’s rights.
Given the long term and cumulative harmful impacts of many developments, the impact on children is relevant to almost any environmental related decision. GC 26 is relevant in countries that have adopted the UNCRC and are monist countries, and can be cited in dualist countries as well.
Human rights law is the law that addresses the fundamental rights and freedoms of individuals. Human rights are protected by international and national law. Every person is entitled to their human rights simply because they are a human being, regardless of age, ethnicity or religion. Under human rights law, the right to private and family life is often intertwined with environmental justice. Additionally, many countries around the world are increasingly protecting the right to a healthy environment. Both the right to a healthy environment, and the right to private and family life, can be used by citizens to demand the protection and restoration of freshwater. When using the more traditional right to private and family life, one must identify harms to citizens, whether through the lack of clean drinking water, odours, pollution, or drinking water contamination. This is contrasted with laws and regulations that protect freshwater for its own sake.
The right to private and family life is protected in international law by the International Covenant on Civil and Political Rights (ICCPR), Article 17. The ICCPR is an international treaty signed by 174 states. There are numerous other international and domestic law instruments which implement human rights law on a national level. The European Court of Human Rights has found that Article 8, the right to private and family life, means that, although there is a balance to be struck between allowing and encouraging economic activity and negative environmental impacts on the other side, citizens have the right not to suffer from unbearable nuisance caused by environmental harms, such as odours and pollution (Lopez Ostra v Spain 1994).
The right to life is another fundamental human right which has been used in claims regarding freshwater pollution where there have been serious risks to health. Access to safe drinking water is also protected under international human rights law.
Example
The claim was brought under several constitutional laws and regulations, including:
The court found that all the above laws had been breached. This case demonstrates how the fundamental principles of the right to a healthy environment and right to water are strengthened by both obligations on the state to realise these rights and the environmental laws and regulations that are designed to implement them.
If considering a legal challenge under human rights law, the first step is to bring a legal challenge domestically. For example, in the UK the right to private and family life is protected under the Human Rights Act 1998, and you can bring a case against a public body for failing to protect your right to private and family life. Before bringing a human rights case, you will need to complain to the authorities about how the environmental pollution is breaching your human rights. If you lose your case against the public authorities in your home country, your lawyer can advise if you have a chance of winning and should appeal to a higher human rights court. Regional human rights bodies offer another layer of protection of human rights beyond domestic law, although the number of cases in which you can make a reference to a higher human rights court is very limited.
In monist systems, international law obligations are automatically incorporated into domestic law and can be enforced directly before national law. There is no requirement to exhaust local remedies. So the UN Convention on the Rights of a Child (UNCRC), for example, can be invoked immediately before the courts in monist systems and can and should be cited as indirectly applicable (e.g. as a tool for interpretation) in dualist systems. Dualist systems do not recognise international law as supreme, and international law must be transposed into national law in order to have effect.
If your home state is subject to jurisdiction by a regional human rights judicial body, CSOs and individuals can bring a claim against the state to a judicial or quasi-judicial human rights body. There are three regional human rights judicial bodies around the world.
These are:
Example
The right to a healthy environment is another human right that is present in hundreds of countries around the world, and is a right that makes it easier for citizens to bring a claim against the government for failing to protect the environment.
Not all countries have the right to a healthy environment enshrined in law, however it is increasingly recognised as an international legal principle. The International Court of Justice, in its 2025 Advisory Opinion on the Obligations of States in respect to Climate Change, recognised that the right to a clean, healthy and sustainable environment is a precondition to the exercise of many other human rights. The Court recognised that the right to a healthy environment results from the interdependence of human rights and environmental protection, and is inherent in the enjoyment of human rights.
Background:
In 2007, the Metal Refinery (EPZ) opened a smelting plant, which recycled used lead-acid batteries in Owino Uhuru. Complaints emerged from the local community following the opening of the plant, alleging that the company was poisoning the environment as a result of poor waste management. Claimants allege that an increasing number of people had been affected by diverse health and environmental impacts, including deaths from lead poisoning and respiratory diseases, since the opening of the plant. Soil tests showed that lead levels increased almost tenfold between 2008 and 2009, when the plant became operational. The smelter ceased operations in 2014, following community pressure and campaigning by the CJGEA.
Outcome:
The community was awarded $12 million in compensation in 2020, but in 2023 the Court of Appeal overturned the decision. The case is ongoing.
In some States around the world, nature itself is considered to possess fundamental legal rights. The idea was introduced to the legal world by an American law professor in 1972, in the landmark article “Should trees have standing?” by Christopher Stone, and has made its way into legal systems around the world since. Rights of Nature as a legal framework aims to move towards a system where nature is valued and protected for its own sake and not simply for the value it provides to humans. This has led in some countries to legal personhood being granted to elements of nature, such as rivers, for example in New Zealand. This allows individuals and organisations to bring legal action on behalf of that river in a similar way to how others might bring claims on behalf of children or companies. Recognising the rights of nature is especially common in Latin America, where Ecuador has included the rights of nature as part of the constitution since 2008. In Ecuador, the Constitutional Court to date has found that rights exist for forests, mangroves, beaches, and a wild monkey in captivity.
As the largest river in Colombia the Atrato River runs for 650km. It is the largest freshwater source in the country and its banks are home to ancestral lands of various Indigenous, Afro-descendent and other minority communities. It runs through a poor and geographically isolated area impacted by internal armed conflict, drug trafficking and intensive illegal gold mining resulting in significant rates of mercury and cyanide contamination. After years of mobilising, a coalition of Indigenous and Afro-descendent communities filed an action for the protection of constitutional rights (tutela action) in relation to the illegal mining. The action filed on behalf of several community and NGO stakeholders against a few dozen public bodies and ministries. After the lower courts found the case inadmissible, the Constitution Court found in favour of the claimants, finding the government had breached the communities fundamental rights, including rights to life, health, water, food security, healthy environment, culture and territory of ethnic communities. Additionally, the court found that the river itself was a subject of rights, recognising the legal personhood of the Atrato River, its basin and tributaries, with rights of protection, conservation, maintenance and restorations by the state and ethnic communities.
The Court ordered a legal guardianship model to be set up for the river, as well as a decontamination plan, a joint action plan to stop illegal mining, toxicological studies, and monitoring and compliance plans.
In it’s reasoning the Court explained:
‘In other words: nature and the environment are a cross-cutting element of the Colombian constitutional order. Its importance lies, of course, in attention to the human beings that inhabit it and the need to have a healthy environment to live a dignified life in decent conditions; but also in relation to the other living organisms with whom the planet is shared, which are understood to be worthy of protection in themselves. It is about being aware of the interdependence that connects us to all living beings on earth; that is, recognizing ourselves as integral parts of the global ecosystem– the biosphere –, rather than from normative categories of domination, simple exploitation, or utility.’
Sadly, illegal mining continues today and the river is still heavily polluted, despite the guardianship of communities, who are reported as feeling ‘powerless’ to clean up the river.
Public trust is a legal concept that understands natural resources, including rivers, to be public assets. This means that they are in fact owned by the nation as a whole, and are run and regulated by the state and public authorities for the benefit of the nation. In legal terminology, this means they are held in a “public trust”, and the public authorities are legally required to ensure the nation is able to enjoy the benefit of the public assets now and in the future. It is unlikely that a country’s legal system will explicitly say that such a public trust exists in relation to nature, although the concept bears similarities to both rights of nature and the right to a healthy environment. There is often a significant overlap between public trust claims and broader claims brought to uphold constitutional protections for the environment.
Almost every legal system in the world includes a similar principle that if you do something wrong that causes damage to someone then you should have to pay for that damage to be made right. In legal terminology, a tort is the wrongful act that causes injury or damage to a person or property and which therefore gives rise to legal liability. Tort law is a way of understanding the rules around what sort of wrongful activity can and should lead to a legal liability to pay damages. Examples include negligence, nuisance and trespass.
The legal liability established in tort law allows the person who has suffered the injury or damage to make a legal claim to have compensation paid to them to correct that injury or damage. One basic example of tort law in practice is if someone is recklessly driving and injures someone by crashing into them. Tort law would allow for the injured person to get compensation from the person who had been recklessly driving the car for causing their injury. More widely, tort law allows people to sue and recover compensation from other people, even if there is no contract between them.
Torts (i.e. the wrongful actions that cause damage to people that deserve compensation) sometimes happen to individual people but often happen to many people at once. This is especially true in instances of pollution that affect a wide area or a commonly used water source. In these situations, the legal principle of class action allows people to come together to bring the same or a similar claim for compensation against those responsible for the wrongful action, rather than each person bringing their claims on their own. This helps people for whom bringing an individual claim might be too expensive. Class actions are common in the US and Australia and in environmental claims. The claimants are usually represented by a single legal team.
Public international environmental law is a vast and complex topic. It is generally of little use to citizens, communities or NGOs as it regulates the legal relationships between different states. It is included here for completeness and because past cases have been brought by governments to prevent pollution generated in one country from negatively affecting the freshwater found in another.
The International Court of Justice (ICJ) is the principal judicial body of the United Nations. Where water pollution is caused by an issue that transcends state boundaries, a state may be inclined to bring a lawsuit against another state to the ICJ. This type of legal action is not easily accessible to citizens, as one would need to have considerable government influence in order to persuade a state to sue another state, and there are international politics involved. However, there are instances of it being used to address pollution. The primary legal instrument governing relationships between states are bilateral and multilateral treaties. Where two states have signed a treaty agreement, if one state has breached that agreement, the other state can bring legal action or initiate arbitration proceedings.
Example
Criminal law relates to crime, such as conduct perceived as threatening, harmful, or otherwise endangering the property, health, or safety of people. In some countries criminal and civil proceedings, such as those explained above and below, can be combined. Typically, environmental crimes are prosecuted by the state, but some jurisdictions allow victims to prosecute crimes directly.
Example
Fourteen countries and the European Union have laws criminalising ecocide— crimes against the environment. One widely used official definition of ecocide, proposed by the Independent Expert Panel as an amendment to the Rome Statute of the International Criminal Court, is ‘unlawful or wanton acts committed with knowledge that there is a substantial likelihood of severe and either widespread or long-term damage to the environment being caused by those acts.’
The court stated, ‘The environmental damage occurring in Vellore District could even be categorized as ecocide, underscoring the urgency of addressing and halting such activities’ [at 92]. The court also confirmed that the right to a healthy environment is contained in the right to life and recognised that the right to clean drinking water is a fundamental right [at 64].
This case demonstrates how environmental rights and broader environmental legal principles such as ecocide aid the courts in addressing non-compliance with environmental laws and regulations.
In some countries, the water companies responsible for providing water to customers may be considered to have entered into a contract with the individuals and communities they supply. Where these companies are also responsible for causing or failing to prevent water pollution in rivers and lakes, it may be possible for individuals to bring a claim for breach of contract. Such claims are rare and difficult to pursue and so therefore an example will not be provided with this guide.