1) The process of extracting water from a natural source, such as a river, lake, aquifer or stream.

2) A financial regime by which a water companies can transform water, sewage and potential ecological damage into economically quantifiable units for economic benefit.

A group that monitors river health, water quality and riverfly populations. Volunteer citizen scientists monitor rivers for pollution incidents with the aims of spreading awareness, improving river health and creating long-term datasets.

1) A truncation of "biological sensor". A biosensor is a chemical sensor device that uses some sort of biological matter, such as an enzyme or a nucleic acid, to interact with the chemical being tested for. The device converts the biological response into an electrical signal.

2) An expanded concept of the biosensor can take into account the different biological responses an ecosystem can have to the introduction of a foreign element, such as sewage. Examples of these responses could be algal bloom, fish death, a decline in species diversity or an increase in disease.

A charity set up in 2012 to care for waterways in England and Wales. It is responsible for over 2000 miles of canals and rivers, as well as other infrastructure including bridges, docks, aqueducts, tunnels and reservoirs.

Science conducted voluntarily by members of the general public, often amateur or non-professional scientists. Citizen science is common in the fields of ecology and conservation. The UK's water networks rely on citizen science networks to measure river health and pollution. This is because of inadequate monitoring from government agencies and the water companies themselves. While these groups have been instrumental in holding water companies to account for their misreported data, why should they bear this responsibility?

Overflow valves originally designed to prevent sewage backing up in the water and sewerage infrastructure during periods of heavy rainfall. They work by releasing a discharge of untreated wastewater directly into water bodies when the sewerage system is at risk of being overwhelmed. CSOs are also being used to dump sewage during periods of no or little rainfall, which is illegal.

The act of keeping something within well-defined limits. This can refer to a material substance, such as the leakage of water or sewage from pipes. But there are also less tangible objects of containment. Flows of finance, migration and ideology can be subject to containment. In many cases, containment is a fantasy, and never fully realisable. In the case of water companies, complete infrastructural containment is literally impossible. Pipes are always leaking water and sewage, and as the frequency of untreated sewage spills indicate, the inability to contain is built into the system. On an economic level, there is no containment of finances as dividends are constantly being paid out to external shareholders who have little or no ecological or social stake in the health of the water.

The introduction of an undesirable element to a system or entity. Sewage, agricultural chemicals and microplastics introduced into a body of water that might negatively affect its surrounding ecosystem can be considered contamination. Water can be impure without being contaminated.

A ministerial department responsible for protecting the environment and rural communities, ensuring standards in food production and supporting agriculture and fishing industries.

An independent body that was formed in 1990 to ensure high standards of drinking water safety across England and Wales.

The average daily flow of waste water to a waste water treatment works (WWTW) when there is no rainfall.

Wastewater that flows from either sewers or industrial outfalls directly into a water body. Effluent can be either treated before entering the water or it can be dumped untreated. Depending on the context and treatment, effluent can contain pollutants.

A non-departmental public body established in 1996 and sponsored by the Department for Environment, Food & Rural Affairs, with responsibilities relating to the protection and enhancement of the environment in England, including the oversight of sewage discharge by water companies.

The inability of water companies to operate in a socially and environmentally sustainable fashion that reflects the true cost of operations. A company could be deemed environmentally insolvent if it was unable to show how it could finance the cost of the transition to being sustainable in its activities, or if it could not estimate the cost of completing that process, or if it concluded that it simply could not make the transition. In his accounting analysis of water companies' financial statements for the last 20 years, founder of the Corporate Accountability Network Richard Murphy declared all England's water companies as environmentally insolvent.

Bacteria found in the environment, food and intestines of people and animals causing diarrhoea, urinary tract infections, respiratory illness and pneumonia, and other illnesses. E. coli bacteria has been found to enter and reproduce in coastal waters through sewage pollution. Rivers polluted by Thames Water have been found to contain levels of E. coli hazardous to human health.

A process of pollution that over-enriches waters with nutrients often caused by nitrate and phosphate pollution from fertilisers. This enables the overgrowth of plant life, leading to the deterioration of water quality. Algal blooms and similar phenomena are an effect of eutrophication.

The process by which a treatment works can monitor whether or not a spill event is happening and how long it lasts for. It cannot provide information on the volume of sewage spilled which can vary dramatically between spills. Household water meters provide this information to water companies. Citizen science groups have been able to collect EDM data when water companies claim they themselves cannot.

The movements of money and funds across sectors and various levels and localities of the economy. By law, all financial flows must be accounted for in a company's annual report. In reality, such flows can be obscured by complicating financial structures, such as in the case of Thames Water.

The notion of circulating waters, or water flows, was formulated by Sir Edwin Chadwick in 1842 in his report on the sanitary conditions of the labouring population of Great Britain. Chadwick saw the need for water to circulate without interruption through the city to avoid stagnating in pockets of pestilence. Water continues to flow in the sewerage and drinking water systems.

A family of thousands of different man-made compounds that do not organically break down in the environment, hence termed "forever chemicals". Many of these chemicals have been banned and many have unknown effects on the human body and the ecosystems they end up in.

An organism, often a microorganism, insect or plant, that serves as a measure of the environmental conditions in a given area.

The process when stormwater and groundwater enter a wastewater sewer system through such means as defective pipes, pipe joints, connections or manholes.

1) In Ofwat's words, leakage is "the water that companies cannot account for; so water that has entered their system but has not been delivered to homes, businesses or used in their operations. Water companies’ leakage targets and figures are based on the pipes that they are responsible for maintaining [...] Leakage can’t be measured; the only way to do that would be to collect every drop that is leaked. It has to be calculated, by adding up all the water put into the supply network and subtracting all the water that has been delivered."

2) Guided by a post-modernist feminist ethic, leakage refers to an inescapable and integral process of flow between and amongst bodies of matter and bodies of knowledge; a resistance to closure.

To observe and check the progress or quality of something over a period of time and keep under systematic review. The Environment Agency (EA) has a responsibility to monitor water companies' spills of untreated sewage into rivers. However, they have left this monitoring to the water companies themselves enacted via a system of self-reporting.

A political ethos that believes in striving towards just futures for all species, including the riverfly, bacteria, human, the sand piper. To take multispecies justice seriously requires the expansion of often human-centred conceptions of rights and justice.

A document that abstracts, obscures or makes mysterious an incredibly complex relationship across different scales. A water bill can be considered a mystifying document as it transmutes a planetary relationship, capturing ecological systems, infrastructure, technology, financial and political actors, animal life, the hydrological cycle and many other areas, into an uncomplicated, bilateral economic relationship between a consumer and their water company. Thames Water's bill takes it a step further in emphasising personal liability in water management, diminishing their own influence in this web of complex relations and shifting the onus of environmental responsibility to the individual.

The non-ministerial government department responsible for economic regulation and price setting of the privatised water and sewerage industry in England and Wales. Ofwat (also known as The Water Services Regulation Authority) was established in 1989 when the water and sewerage industry was privatised. Thames Water CEO Cathryn Ross was previously CEO of Ofwat.

A set of targets introduced by Ofwat in 2014 for the Water Companies it regulates. ODIs aim to broaden Water Companies' concerns from output alone to attend to environmental impact, technical innovation and service improvements. At each price review, Ofwat sets water companies service targets ("performance commitments"). If a company performs better than the performance commitment level, it may get a financial reward ("outperformance payments"). If a company performs below the performance commitment level, it may pay a financial penalty ("underperformance payments").

Material assemblages which have become contaminated by the presence or introduction of harmful or poisonous substances.

Water that has been treated and tested as safe for human consumption. The Drinking Water Inspectorate (DWI), defines potable drinking water as "[defined] in law mainly by setting standards for a wide range of substances, organisms and properties of water in regulations. There is an additional requirement to make sure that it does not contain anything else that might be a potential danger to human health, as identified by risk assessment."

The process by which a government body or operation comes into private ownership, becoming a non-government corporation that has the ability to generate profit, even from basic needs such as water.

Infrastructure used for a number of different systems, including the supply of water to canals, drainage of water from flood-prone land and the removal of sewage to wastewater processing sites.

The quantity or volume of rain falling within a given area, in a given time. During periods of rainfall, water companies can legally use CSOs to dump untreated sewage into bodies of water. There is no defined threshold for how much rain permits this.

The oversight of water companies by the various governmental and government-adjacent bodies in England and Wales through legislation and policies. Regulation could also refer to independent financial auditors, such as PricewaterhouseCoopers (PwC). PwC was auditor to Thames Water at the same time as it advised Ofwat for its review of water companies' prices.

The amount of different species that exist in a given ecosystem, which can also be referred to as species richness. Species abundance refers to the amount of a species in the ecosystem. Together they are used to indicate the overall health and biodiversity of an ecosystem. Rivers are often areas of high species diversity/abundance, but pollution from sewage spills, agricultural runoff, industrial work and other sources often causes this to decline. Occasionally this pollution can cause one particular species, such as algae, to dominate a river's ecosystem.

1) Legal or illegal release of excess wastewater and rainwater directly from wastewater treatment facilities via Combined Storm Overflows (CSOs) into inland waterways and the sea. A spill is often enacted to prevent the risk of flooding and sewage backing up into streets and homes when the sewerage system is at risk of being overwhelmed. Spills can be caused by an extra volume of water passing through the sewer network, amassed during heavy rainfall for example, or by issues in the infrastructure, such as clogged or aging pipes.

2) A dry spill is a spill that happens when there is no heavy rainfall. Dry spills are illegal but hard to catch due to ineffective monitoring. Data processed by Windrush for Sewage Pollution (WASP) for 2021 showed that Thames Water dry spilled 372,533 times that year for a total of over 2.75 million hours.

Integral components of the drainage and sewerage system, engineered to manage the surge in water flow caused by rainfall and to mitigate pollution or uncontrolled releases into nearby ecosystems, such as rivers, seas or other bodies of water.

Rainfall that does not infiltrate the ground or evaporate because of impervious land surfaces in urban or built environments. Stormwater runoff instead flows into adjacent lands, other water courses or sewage systems. Stormwater runoff can cause sewage systems to be overwhelmed.

Water that occurs beneath the earth's surface, including soil moisture and groundwater. It is distinguished from surface water which amasses in large bodies such as oceans, lakes and rivers.

A marine conservation charity protecting ocean waters and marine life from pollution.

An environmental charity and umbrella organization for 63 non-profit member rivers trusts across the United Kingdom that develop projects to enhance the long-term ecological health of rivers.

The point beyond which some new action or different state of affairs is likely to begin or occur; the starting point for a new state. Considering the moment when a boundary is crossed allows us to consider the following questions. When is a sewage discharge considered illegal? What is the level of pollutants at which a body of water considered contaminated? At what point of financial insolvency is a company considered unsustainable?

Also known as the Super Sewer; a 16 mile-long combined sewer running under the estuary of the River Thames, across Inner London. The Tideway Tunnel is under construction, slated for completion in 2025, being paid for by Thames Water's customers. Once constructed, it aims to capture, store and convey almost all the raw sewage and rainwater that currently overflows into the estuary.

1) The quality of allowing light to pass through objects; to be easily seen through.

2) The practice of operating in openness and accountability, such that other persons are able to see all decisions and actions taken.

Water that has been contaminated, or affected in quality, by human influences. Wastewater includes all of the liquid waste from residential, commercial, industrial and agricultural use.

A site at which domestic, industrial and agricultural water treatment processes take place. Wastewater treatment is a process which removes and eliminates contaminants from wastewater, converting this into an effluent that can be returned to the water cycle. It is sometimes called a Sewage Treatment Plant (STP).

Defined in chemical terms, pure water is water containing only hydrogen and oxygen molecules and is typically only found in controlled environments. The concept of water purity is more commonly linked to the level of contaminants in water and its intended use, such as drinking, bathing or fishing.

A private, for-profit entity licensed by the UK government to supply water and wastewater services to household and non-household customers. Many of the UK's water companies hold a de facto monopoly on the supply of these services.

The contamination of a stream, river, lake, ocean, aquifer or other body of water by harmful substances, often chemicals or microorganisms. Pollution can degrade water quality and seriously affect ecosystems.

A process of removing, or reducing the concentration of, contaminants in water to improve its quality. Wastewater can undergo treatment so that it is, in theory, safe to release into rivers.

A grassroots group of activists based near the River Windrush in Oxfordshire. Co-founder Peter Hammond has been crucial in collecting and analysing data of water companies' illegal wastewater overflows.