Before Clean Water
Before the 19th century, Londoners knew better than to drink water straight from the Thames.
The river was an open sewer:
- Human waste
- Industrial effluent
- Animal carcasses
- Slaughterhouse runoff
What people drank instead:
- • Beer — safer than water
- • Wine — for those who could afford it
- • Whatever they could find — the poor
People knew dirty water caused illness. They just didn't understand how.
The Cholera Epidemics (1831-1866)
Cholera arrived in Britain in 1831. It spread through contaminated water with terrifying speed.
Death Toll
| Epidemic | Year | Deaths |
|---|---|---|
| First | 1831-32 | ~32,000 |
| Second | 1848-49 | ~62,000 |
| Third | 1853-54 | ~20,000 |
| Fourth | 1866 | ~14,000 |
| Total | 128,000+ | |
Over 128,000 deaths from a preventable waterborne disease.
Dr John Snow's Discovery (1854)
Physician John Snow mapped cholera deaths in Soho during the 1854 outbreak.
What he found:
Cases clustered around one water pump on Broad Street.
What he did:
Convinced authorities to remove the pump handle.
What happened:
The outbreak stopped.
Snow proved cholera spread through water, not "bad air" as doctors believed. It took years for the establishment to accept he was right.
The lesson: Sometimes experts are wrong. Sometimes the water that looks clean isn't.
The Great Stink of 1858
By the 1850s, London had a crisis: too much sewage, nowhere to put it.
The situation:
- 2+ million people
- Cesspits overflowing into streets
- Everything draining into the Thames
- Same river supplied drinking water
Summer 1858: A heatwave turned the Thames unbearable.
The smell reached Parliament. MPs couldn't work. They covered windows with lime-soaked curtains.
The result: After decades of ignoring sanitation reform, Parliament suddenly found the will to act.
The lesson: Authorities often ignore water problems until they personally experience the consequences.
Bazalgette's Sewers: The Solution
Engineer Joseph Bazalgette built what seemed impossible:
The Numbers
| Element | Scale |
|---|---|
| Street sewers | 1,100 miles |
| Main intercepting sewers | 82 miles |
| Bricks used | 318 million |
| Completed | 1875 |
The result:
- Cholera never returned to London
- Life expectancy increased
- Thames slowly recovered
Still in use today — 150 years later.
The lesson: Good infrastructure works for generations. Poor infrastructure costs lives.
Privatisation (1989): The Turning Point
Margaret Thatcher's government privatised England and Wales's water supply.
What Was Promised
- Private investment would modernise infrastructure
- Competition would improve service
- Customers would benefit
What Actually Happened
- ~£78 billion paid to shareholders
- £60+ billion debt accumulated
- Victorian infrastructure still in service
| Metric | Reality |
|---|---|
| Dividends paid to shareholders | ~£78 billion |
| Debt accumulated | £60+ billion |
| Designed capacity | 2 million people |
| Actual users | 9 million people |
The sewers Bazalgette built for Victorian London now serve a city 4x larger.
Want the full breakdown? See our fact-checked investigation: Who Owns UK Water Companies? The Shareholders Behind Your Tap
The Modern Sewage Scandal (2020-Present)
Since 2020, water companies have been dumping raw sewage into UK waters on an industrial scale.
Annual Sewage Discharges
| Year | Hours of Discharge | Incidents |
|---|---|---|
| 2020 | 3.1 million | 400,000+ |
| 2021 | 2.7 million | 370,000+ |
| 2022 | 1.75 million | 300,000+ |
| 2023 | 3.6 million | 460,000+ |
This isn't exceptional circumstances. This is routine.
Every water company in England and Wales is now under investigation.
Why It's Happening
- Underinvestment since privatisation
- Climate change increasing storms
- Housing development outpacing capacity
- Weak regulatory enforcement
- Cheaper to pollute than fix
What This Means For Your Tap Water
You might think: sewage goes into rivers, but my tap water is treated separately.
Yes and no.
Many UK water supplies come from rivers — the same rivers receiving sewage.
What Treatment Doesn't Fully Remove
| Contaminant | Removed by Treatment? |
|---|---|
| Bacteria | Yes |
| Viruses | Yes |
| PFAS (forever chemicals) | Partially |
| Microplastics | Partially |
| Pharmaceutical residues | Partially |
The DWI confirms 99.96% compliance. But 0.04% = thousands of failures annually.
The Pattern of 200 Years
- Authorities deny problems until they can't
- Investment lags until crisis forces action
- The poor suffer most
- Private profit vs public health creates tension
Why People Filter Their Water
Given this history, millions of Britons choose not to trust tap water completely.
It's not paranoia. It's pattern recognition.
Modern filters can remove:
- Chlorine (taste, byproducts)
- Lead (from old pipes)
- PFAS (not fully removed by treatment)
- Microplastics (unregulated)
Frequently Asked Questions
When did UK tap water become safe to drink?
UK tap water became significantly safer after Bazalgette's sewage system (1870s) and chlorination (early 1900s). However, contamination incidents have occurred throughout the 20th and 21st centuries. "Safe" is a spectrum, not an absolute.
Why is there sewage in UK rivers?
The UK's combined sewer system mixes rainwater with sewage. During heavy rain, it overflows into rivers through "combined sewer overflows" (CSOs). Designed for emergencies, these have become routine due to underinvestment.
Has anyone died from UK tap water?
Waterborne deaths are rare but not zero. The Camelford contamination (1988) has been linked to at least one death. Cryptosporidium outbreaks have killed immunocompromised individuals.
Why don't water companies fix the problem?
Fixing the system requires tens of billions in investment. Since privatisation, companies have prioritised shareholder dividends over infrastructure. Regulatory pressure is increasing, but meaningful fixes will take decades.
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Keith Wilks
Water Filtration Specialist | 24+ Years Experience
Keith has spent over two decades helping people understand water quality and find practical solutions for their homes. He believes in honest, evidence-based advice.
Read full bio →Last updated: January 2026. We review and update our content regularly to ensure accuracy.