5 most common water industry bacteria; what are they and how do they affect us?

In the UK we are fortunate to have a clean water source in our homes, this is a luxury the majority of us take for granted.

Think about this:

According to “Progress on Drinking Water, Sanitation and Hygiene” published by the World Health Organization in 2017:

  • 844 million people still lacked even a basic drinking water service.
  • 263 million people spent over 30 minutes per round trip to collect water from an improved source (constituting a limited drinking water service).
  • 159 million people still collected drinking water directly from surface water sources.

A sobering thought isn’t it……

When I turn on a tap in the UK I am almost 100% confident that the water coming out of it is clean and safe to drink.

How do water companies keep our drinking water safe?

I have learnt that all drinking water in the UK goes through a tried and tested sedimentation process, filtration process and a chemical treatment process to ensure that all solids, contaminants and pathogens are removed to safe guard consumers.

However, utility companies can’t rest on their laurels; adverse weather, equipment failures or contamination in the water delivery systems, can lead to unsafe water occasionally slipping through the net.

Having said that, the incidence rate of outbreaks of water borne disease in recipients of private water supplies may be as high as 35 times the rate in those receiving public water supplies.

What waterborne pathogens are present in our water system and what affects do they have on us?


Cryptosporidium (Cryptosporidiosis, Crypto)

Key facts:

  • Cryptosporidium is a protozoan (single celled) parasite which, if ingested, can cause an illness called cryptosporidiosis.
  • The main symptom in humans is watery diarrhoea, which can range from mild to severe. It is often accompanied by stomach pain, nausea or vomiting, fever and sometimes dehydration and weight loss.
  • Anyone can become infected with Cryptosporidium, although illness is most common in children between 1 and 5 years of age.
  • In UK water supplies it is the biggest problem by some distance being implicated in an estimated 70% of disease outbreaks

There are several ways you can become infected with Cryptosporidium:

  • Drinking infected water
  • Directly from another person or animal by touching faeces i.e. changing nappies and not washing your hands and the inadvertently putting your hands to your mouth.
  • Swimming in already infected water
  • Eating and drinking contaminated food i.e. unpasteurised milk, under cook meat and offal (liver, kidneys, and heart)


Key facts:

  • Campylobacter is 1 of 4 key global causes of diarrhoeal diseases. It is considered to be the most common bacterial cause of human gastroenteritis in the world.
  • In the UK drinking water it is less prevalent than Crypto but still accounts for around 15% of outbreaks
  • Campylobacter infections are generally mild, but can be fatal among very young children, elderly, and immunosuppressed individuals.
  • Campylobacter species can be killed by heat, effective disinfection of water, and thoroughly cooking food.

There are several ways you can become infected with Campylobacter:

  • drinking infected water
  • eating contaminated, under cooked meat, especially chicken.
  • drinking contaminated water or unpasteurised milk.
  • eating food (such as salad) that has been cross-contaminated with Campylobacter from raw meats/poultry.
  • handling young pets, other animals, raw meat and pet meat.
  • person-to-person spread.
E Coli

Escherichia coli (E. coli)

Key facts:

  • Escherichia coli (E. coli) is a bacterium commonly found in the lower intestine of warm-blooded organisms.
  • Most E.coli strains are harmless, but some can cause serious symptoms such as nausea, vomiting, diarrhoea and abdominal cramping.
  • In most cases, the illness is self-limiting, but it may lead to a life-threatening disease including haemolytic uraemic syndrome (HUS) which causes kidney failure, especially in young children and the elderly.
  • Most intestinal infections are caused by contaminated food or water.
  • Proper food preparation and good hygiene can greatly decrease your chances of developing an intestinal infection.

Symptoms of intestinal infection generally begin between 1 and 10 days after you’ve been infected with E. coli. This is known as the incubation period. Once symptoms appear, they usually last around 5 to 10 days.

Symptoms can include:

  • abdominal cramping
  • sudden, severe watery diarrhea that may change to bloody stools
  • gas
  • loss of appetite or nausea
  • vomiting (uncommon)
  • fatigue
  • fever

Symptoms can last anywhere from a few days to more than a week.

Symptoms of a severe E. coli infection may include:

  • bloody urine
  • decreased urine output
  • pale skin
  • bruising
  • dehydration

Legionella (Legionellosis)

Key facts:

  • Legionellosis is a collective term for diseases caused by legionella bacteria including the most serious Legionnaires’ disease, as well as the similar but less serious conditions of Pontiac fever and Lochgoilhead fever.
  • Legionnaires’ disease is a potentially fatal form of pneumonia and everyone is susceptible to infection. The risk increases with age but some people are at higher risk including:
  • people over 45 years of age
  • smokers and heavy drinkers
  • people suffering from chronic respiratory or kidney disease
  • diabetes, lung and heart disease
  • anyone with an impaired immune system
  • The bacterium Legionella pneumophilaand related bacteria are common in natural water sources such as rivers, lakes and reservoirs, but usually in low numbers. They may also be found in purpose-built water systems, where water is stored, exposed to temperature fluctuations or aerosolised, such as cooling towers, evaporative condensers, hot and cold water systems and spa pools.
  • People contract  Legionnaires’ disease by inhaling small droplets of water (aerosols), suspended in the air, containing the bacteria
  • The symptoms of Legionella are similar to that of the flu.
  • high temperature
  • Feverishness and chills
  • Cough
  • Muscle pains
  • Headache
  • Pneumonia
  • Very occasionally diarrhoea and signs of mental confusion.
  • The illness is treated with an antibiotic called erythromycin or a similar antibiotic.


Key facts:

  • Salmonella is 1 of 4 key global causes of diarrhoeal diseases.
  • Most cases of salmonellosis are mild; however, sometimes it can be life-threatening. The severity of the disease depends on host factors and the serotype of Salmonella.
  • Antimicrobial resistance is a global public health concern and Salmonella is one of the microorganisms in which some resistant serotypes have emerged, affecting the food chain.

You become infected with Salmonella by ingesting the bacteria through your mouth. This can be by:

  • eating contaminated, undercooked meat (most commonly chicken)
  • eating contaminated raw or undercooked eggs
  • eating food that has been cross-contaminated with Salmonella from raw foods (especially meats, poultry and eggs)
  • handling pets, other animals, raw meat and pet meat
  • drinking water that has been contaminated, usually by animals or sewage.
  • drinking infected water

Person-to-person spread can happen if you come into contact with microscopic amounts of faeces (poo) from an ill person. Such spread may occur directly by close personal contact, or indirectly by touching contaminated surfaces such as taps, toilet flush buttons, toys and nappies.

They all sound pretty dire, right?

Can you imagine if these pathogens were not controlled properly, allowing them to infect a town, city or even a regions water supply?


What about the 844 million people that still lack basic drinking water?

What can be done for the 159 million people drinking from surface water sources?

Stringent water disinfection is not the case in the developing world…yet

What can be done to help the world water crisis?

At Bridge Biotechnology we build ESOL™ generators.  These generators use only salt, water and electricity to produce an electrolyzed water called ESOL™.

Electrolyzed water can be used as a direct chlorine replacement in drinking water however it safe to handle and not costly to produce.

ESOL™ is more effective at killing pathogens than Chlorine and it also has residual kill which means the bacteria and viruses carry on being eliminated after it is added to the water source.

Working with the University of the West of England and Portsmouth Aviation, we have established a portable drinking water system capable of delivering clean drinking water at source.

What next?

Water industry

Do the water disinfection methods applied in your business need reviewed? With continuous improvement in mind, would a safe sustainable option be better for your business?

We have reviewed some of the most commonly used water disinfectants in the water industry below, we would love to know what you think

Related content: Most commonly used water disinfectants reviewed: an honest opinion






Leave a comment

Your email address will not be published. Required fields are marked *