Introduction
While sewage spills demonstrate a clear violation of environment and public health, their social and material impacts are more obscure. Who suffers when water is polluted and who can pay their way out of the problem? As water travels from source to glass, it encounters the failures of privatised infrastructure, which it passes on to our bodies.
To be drinkable, water undergoes a process of "abstraction" through which it is removed, cleaned and treated into its commodity form. This means that even though the river is employed as a "forgetting mechanism" by water companies into which our wastewater and sewage are discharged, it doesn’t just disappear. To drink a glass of water is to come into contact with all of the liquid bodies from which that water was drawn and through which it travelled.
Water Treatment
London's water treatment involves two primary facilities: Coppermills and Hampton. During this process, water passes through a screen to eliminate large debris like branches or leaves. At Coppermills, the water undergoes two rounds of filtration: first, the rapid gravity filters, which operate in approximately 15 minutes, effectively remove more substantial sediment. Then, ozone gas is introduced into the water, a step known as ozonisation, which serves to eradicate bacteria and oxidize pesticides and organic materials. Subsequently, the water flows through slow sand filters, which not only remove finer sediments but also harbour a biofilm layer for the biological treatment of contaminants. Finally, the water receives a dose of chlorine before being reintroduced into the system.
The tap and pie chart represent the quality of drinking water received by consumers, and the numbers and parameters which failed to meet the standards in 2022. DWI, 2022
The increased amount of contaminants inside the supply water requires an increased amount of chemicals to clean the water which could potentially impact the system’s performance. The Drinking Water Inspectorate report reveals that Thames Water had 115 compliance breaches in 2022 alone. Another statistic from the report illustrates that the breaches with the highest CRI scores originated from Coppermills and Hampton water treatment works.
E. Coli
image inspired by appearance of small rod shape E. coli under light microscope. (100x)
Approximately 70% of London's water supply is drawn from the upstream section of the Thames River of Teddington, but sewage discharges from UK water companies pose a significant threat to river ecosystems and contribute to increased levels of E. coli (Escherichia coli) bacteria, commonly found in human and animal intestines. As our water supply originates from these contaminated rivers, the prevalence of E. coli rises. E. coli infections, often transmitted through contaminated food, water or contact with infected animals and environments, can lead to severe health consequences such as gastroenteritis, bloody diarrhoea, kidney damage, and, in rare cases, life-threatening conditions like Hemolytic Uremic Syndrome (HUS). Compounding these concerns is the underreporting and infrequent E. coli testing by water companies, as documented in the Drinking Water Inspectorate Report 2022, leaving the reliability of data on E. coli presence in our drinking water uncertain.
Threshold of Responsibility
In London, water is pumped through a series of networked pipes. Despite clear evidence of lead’s harmful impacts on health, there is no legal requirement for water companies to replace lead piping. The water industry estimates that almost a quarter of domestic properties across England and Wales still have lead pipes in their supply network. Just 4 per cent of lead pipes in the UK are thought to have been replaced by the water companies responsible for them. Further reports show that Thames Water have spent £82.7m replacing 89,465 lead pipes, but do not provide a figure for the amount of lead pipes that remain. Moreover, they covertly displace this responsibility onto the consumer: their website, which makes no mention of the above information, states that “Our water mains aren’t made of lead, and there’s virtually no lead in the drinking water leaving our treatment works. However, you may have a lead pipe feeding your property or in your internal plumbing. If so, small amounts of lead may dissolve into your water.”
Lead
Alongside the dissolving footprint of E. coli, there are other contaminants hidden in our water supply. Thames Water infrastructure contains an undisclosed quantity of lead piping, a substance that has been deemed injurious to public health. From the 1600s to the end of 1700s, drinking water used to be supplied to the public through a network of wooden pipes, with supplementary lead piping for those who could afford it. Lead was framed as a more robust and effective method of water transfer, exclusively provided for the wealthy. Scientific knowledge today, however, shows that any amount of lead is toxic. The recommended maximum allowable amount in UK water is 10 micrograms per litre, but under World Health Organisation guidance, there is “no level of exposure to lead that is known to be without harmful effects”. In keeping with this guidance, the US has lowered their limit to zero in recognition that there is no level of lead that is safe for humans. For children, lead contamination can lead to neurological problems and adverse impacts on development and growth. For adults, lead contamination can lead to fatigue, confusion and tiredness – symptoms that are difficult to measure and trace. As a result, lead contamination can occur covertly.
A Tale of Two Cities
Site specific research found that London water, in general, has a markedly higher lead concentration than the rest of the UK. More specifically, South London has one of the highest levels of lead in the UK (2.60μg/l), followed by West Sussex (1.65ug/l), and much of the North West (1.29μg/l).
While the UK legal limit for lead contamination (10μg/l) means that these quantities are deemed negligible, wider scientific evidence that there is no safe level of lead suggests a set of hidden considerations that operate to the advantage of water companies, who can evade responsibility for pipe replacement by remaining below the designated threshold.
This can also be set against the architecture of social inequality in London. In Philimore Gardens (W8 7QE) where the average house price is £9,300,000, mean lead quantity (Pb) was <0.9 μg/l. Near Goldsmiths, University of London (SE14 6NW), where the average house price is £410,700, mean lead quantity (Pb) was 4.2 μg/l. Water hardness was also higher in SE14. Health disparities between the boroughs cannot be correlated to this without further data, but given that effects of lead contamination are often intangible, there is a probability that water disparities feed into wider health and social inequality.