Water

A personal perspective

Why can animals drink from puddles and streams and consume other doubtful looking water and not get ill?

Why is it only humans that need to add chlorine and otherwise treat water before it can be considered ‘safe’ enough to drink?

I got curious about this and started doing some superficial digging to see what I could discover and to try and assess the likelihood we are being told the truth.

I did an internet search: “Why can animals drink from puddles but not humans” and I got this —

Wild animals can drink from puddles primarily due to repeated exposure and evolutionary adaptations, whereas humans generally cannot because of lower body temperatures and lack of specific immunity.

• Acidic Stomachs and Higher Temperatures: Many animals, such as dogs and vultures, have highly acidic stomachs that kill pathogens, and their higher body temperatures (100–103°F) act as a defence against waterborne microbes adapted to cooler river or puddle temperatures.

• Microbial Familiarity: Animals develop resistance to local bacteria and parasites through constant exposure, creating a symbiotic gut flora that humans lack.

• Human Vulnerability: Humans run cooler (98.6°F) and have evolved away from raw environmental exposure through cooking and sanitation, making our immune systems less equipped to handle the high pathogen loads found in untreated natural water sources.

• Survivorship Bias: It is a misconception that animals do not get sick; wild animals frequently suffer from parasites and waterborne diseases, but sick animals are often removed from the wild by predators or fail to survive.

Does this sound like solid reasoning to you? I’ll discuss what I think about this below.

I also searched: “Water purification” and this text from Superdrug was interesting which I have edited down.

Water Purification – What You Need To Know

It’s important to stay hydrated on holiday. But be careful, there’s a range of nasty bacteria you could catch by drinking or using contaminated water. Contaminated water causes 80% of travel-related illnesses like travellers’ diarrhoea, hepatitis A, typhoid and cholera which can be avoided by buying treated water or by purifying water yourself.

Unsure? Don’t panic Superdrug have this handy guide.

What’s safe to drink?

• Bottled water, fizzy drinks, beer and anything sealed

• Boiled water — boiled for one minute.

• Tea or coffee made with boiled water.

What should I avoid?

• Anything unmarked or on tap in poor countries.

• Ice in your drinks.

If in doubt, don’t drink! Even brushing your teeth with untreated water can be dangerous!

What if I don’t have bottled water or sealed drinks?

There are several ways to treat water yourself and it’s best to have a back-up plan in case you run out.
Luckily there are gizmos and gadgets to make it easy to purify water on the move which can be found online or at travel equipment shops.

Portable Water Filters/ Purifiers

Handy products like LifeStraw® or LifeStraw®Go are great, portable and re-useable. LifeStraw® filters bacteria, parasites and debris and fits in your pocket. LifeStraw®Go is a bottle with a filter attached into the top. As well as filtering, these modern filters also chemically disinfect or purify water using advanced fiber technology. This means you’re protected from viruses and harmful bacteria. Remember: if you are using a water filter that doesn’t protect against bacteria, you’ll need to treat it with one of our other methods before using it.

Boiling

This is the oldest method but reliable. Boiling unfiltered water makes it safe. Boiling for one minute is enough to kill all dangerous bacteria. Generally though, we suggest boiling water for three minutes – especially at altitude.

If you’re saving the water for later it should be cooled and covered to avoid contamination.

Chemical Purification (Halogens)

Halogens are cheap, easy to use and carry. Here are some:

• Chlorine Dioxide: available in tablets and effective for killing bacteria, viruses and parasites. Can leave a funny taste in the mouth

• Chlorine and silver based tablets: buy from chemists these handy tablets are useful for destroying most bacteria that cause cholera etc but less effective at guarding against viruses and cysts. Chlorine tablets work best in combination with products like Aquamira®, containing phosphoric acid.

• Iodine: since 2009, the use of iodine tablets has been banned in the EU, so are difficult to find but it’s still effective for chemically purifying water.

Other Methods

• Sodium Chloride (Salt) Electrolysis: this hand-held device is fantastic for treating water without harsh chemicals by passing an electrical charge through a salt-water solution to produce oxidants like hypochlorite. You’re left with a solution you can add to untreated water to destroys the active agent within most bacteria and viruses.

• UV Radiation: products like SteriPEN® use ultraviolet light to destroy over 99.9% of bacteria and viruses. Small portable pen-like device needs AA batteries. There is evidence this method works, but it relies upon using clear and filtered water to begin with.

Let’s do a bit of thinking before we take anything here too seriously.

First let me say I lived many years on a small Caribbean island with no mains water. So we caught what fell from the sky, directing the roof rainwater into a great big concrete 25,000 imperial gallon cistern. It was big because sometimes there was no rain for over six months or more. Locals often added fish to their cisterns they called ‘millions’ on the basis if you had healthy fish then you had healthy water. I never did this as the idea of it put me off a bit. The fish apparently ate any mosquito larvae.

But birds and lizards would presumably crap in my gutters and this got washed into my cistern when there was a rain shower. Since we had an AirBnB next door using the same cistern I felt obliged not to poison our guests so I put all our domestic water through a commercial UV purifier and no guests were ever harmed. My understanding was the UV (ultraviolet) didn’t kill any evil germs lurking in the water it just rendered them harmless by altering their DNA??? or some such baloney so they couldn’t reproduce.

So it was okay to drink water with either dead germs in it or ones that had somehow been made infertile. Interesting!

But to be super-safe I thought I would really need to add chlorine like they do in the water companies.

I actually did do this for all the water in my cistern after careful calculation of the optimum parts per million which was not an easy calculation.

And the water tasted horrible so I never did it again. The chlorine eventually sort of evaporates out so you are supposed to keep doing it but once was enough for me.

Continuing my internet research I delved some more and found this article text which again I have edited down:

How To Make Cistern Water Drinkable

By Barry Chenkin

Water security is important and I’ve spent two decades helping people harness rainwater. Collecting rainwater in a cistern is excellent, making the water safe to drink requires proper treatment. Many assume rainwater is naturally pure, but contaminants can enter the cistern.

How Cistern Water Becomes Contaminated

Rainwater starts relatively clean, but can pick up harmful contaminants from collection. Common risks include:

• Bacteria & Viruses: Cistern water can harbour E. coli, Giardia, and Legionella if not properly treated.

• Heavy Metals & Toxins: Roofing materials, airborne pollutants, and industrial runoff can introduce lead, pesticides, and other contaminants.

• Debris & Organic Material: Leaves, insects, and algae growth can degrade water quality and create breeding grounds for bacteria.

Common Sources of Contamination

• Roof Runoff: Roofing material may leach harmful chemicals into the water.

• Improper Sealing: Open or cracked cisterns allow dust, bacteria, and small animals to enter.

• Stagnant Water: Lack of circulation fosters bacterial growth and sulfur smells.

Debunking Myths About Rainwater Safety

• Myth: “Rainwater is naturally pure.” While cleaner than surface water, rain picks up pollutants from the air and roof.

• Myth: “Boiling is enough to make cistern water drinkable.” Boiling kills bacteria but doesn’t remove heavy metals or chemicals.

• Myth: “Historical civilizations only drank beer to avoid contaminated water.” Ancient societies identified safe water sources, but storage and filtration were still necessary.

How To Make Cistern Water Safe to Drink

Step 1: Pre-Filtration – Keeping Debris Out

Flush diverters to eliminate the most contaminated portion of rainfall, keeping pollutants out. Leaf screens and sediment traps serve as the next line of defense, blocking large debris that could introduce bacteria or clog filters. UV-resistant tank liners prevent microbial growth inside the cistern, reducing biofilm buildup. These create good water storage ready for proper purification and use.

Step 2: Filtration Methods for Cistern Water

Clean water starts with smart filtration. Activated carbon filters effectively remove chlorine, chemicals, and odors, improving taste and safety.

For deeper purification, membrane filtration—such as reverse osmosis or ultrafiltration—eliminates microscopic contaminants, ensuring high-quality drinking water.

A lesser-known but powerful solution is copper storage vessels. Their natural antimicrobial properties help reduce bacterial growth, adding an extra layer of protection.

Combining methods can create a multi-barrier approach to water safety.

Step 3: Disinfection Methods

Boiling is time-tested but impractical for treating large volumes of cistern water.

For more efficient disinfection, chlorination offers a reliable way to kill bacteria. Adding the right amount of bleach per gallon ensures safe drinking water, though it requires careful measurement to avoid overuse.

For chemical-free options, UV purification neutralises harmful pathogens using light, while ozone treatment provides advanced, large-scale disinfection.

In emergencies, DIY solutions like solar disinfection or iodine tablets can offer quick, temporary water safety until a permanent system is in place.

How Do I Know My Cistern Water Is Safe To Drink?

To ensure your cistern water is safe to drink, conduct regular testing for bacteria, pH levels, and heavy metals. Consistent monitoring helps detect contamination. At-home test kits or professional analysis ensures your water remains clean, safe, and suitable for consumption.

Why Does My Cistern Water Smell Bad?”

A sulfur smell in your cistern water often signals bacterial growth or stagnant water. Regular cleaning, aeration, and proper filtration can help eliminate odours. Treating the water with chlorination or activated carbon filters ensures freshness, making it safe and pleasant to use.

How To Maintain a Cistern for Long-Term Water Safety

Proper maintenance is key to keeping cistern water safe. Sealing and covering the system keeps out airborne pollutants, animals, and debris, reducing contamination.

Mosquitoes can quickly turn a cistern into a breeding ground, so adding larvicide and ensuring a secure seal is essential. For emergency preparedness, a collapsible storage bladder provides a potable backup supply.

Lastly, regular filter replacements maintain peak performance, ensuring your filtration system effectively removes bacteria and contaminants.

Thoughts

These are my thoughts — but please do your own homework and think for yourself.

Why would nasty stuff (germs) in water only affect tourists and not the locals who drink the water all the time? Surely any illness experienced might be just an adjustment being made to new stuff in the water or possibly to new food or other factors and toxins in your changed local environment. But let’s blame the water.

Why are humans seemingly unable to deal with supposed germs in the water because we run only 4 degrees cooler than dogs who run at 103 degrees F? And yet they say boiling water is apparently needed to kill terrible germs which is twice as hot at 212 degrees F. This makes no sense to me at all and appears to be utter twaddle.

They mention other animals have more acidic stomachs to kill ‘pathogens’ but how do all the supposedly good gut bacteria you ingest in probiotic yoghurt, etc survive? They imply nothing would get past this acid bath to the intestines beyond and yet the gut is teaming with trillions of bacteria without which we’d all be dead. I’m not seeing much beyond bullshit here.

We are vulnerable [because we have evolved away from raw environmental exposure through cooking and sanitation, making our immune systems less equipped to handle the high pathogen loads]. What a load of tosh — there is no evidence we even have an immune system in the way it is commonly described. They actually also inconveniently imply humans used to survive perfectly okay for thousands of years before we invented cooking and sanitation.

I’d be eager to know exactly how we involved out of being able to deal with germs in water when you would think evolving ‘the other way’ to be able to deal with more of them was a far more positive thing for the survival of our species.

Since germs are not the cause of illness but usually arrive (or evolve by pleomorphism) afterwards to sort things out, might the ones we are being told are evil and present actually be there because of some unsavoury squalid conditions? Hence the conditions might make you ill and not any germs that might be present alongside.

How can it be possible that we need to make the water somehow ‘better’ by adding nasty toxic chemicals that supposedly kill evil germs when presumably the same chemicals would also be able to kill supposedly good germs as well? These are very clever chemicals that can be so selective.

We are told when the water improves in places so does life expectancy and general health. But is this actually the water itself doing the ‘heavy lifting’ or is it the improvements that come alongside like better sanitation, washing, etc that then make the place less squalid? So water arrives at the same time as the health improvements but it is only indirectly associated …and the germ-theory aspect is just a nice easy explanation for what actually happens.

Note: Near where I currently live in Lichfield in the U.K. in 1873 the Victorian Sandfields Pumping Station was created to supply 2 million gallons of water per day to towns 18 miles away in the industrial Black Country where local wells were often polluted, and where there had been cholera epidemics in 1832 and 1849. The provision of clean water played a significant part in the growth of the industrial revolution, and added twenty years to the average life expectancy of everyday working people. But were these 20 years added by the eradication of the germs in the water people drank or by folks now being able to wash and generally live to a better standard?

My thinking is that the concept of never touching water that might be less that totally pure is part of the same fear-mongering that sells you hygiene as necessary to stay alive and keeps you terrified of germs — which are always scapegoated for illnesses actually caused by environmental toxins.

As a complete aside we are told we need to drink tons of water. I am certainly not saying what is good or bad about this advice but I drink almost none — as water.

I’ll have tea, beer, raw milk, orange juice, etc but never fizzy pop. I assume my body somehow manages my hydration level on what it gets given. I have actually drunk water directly from nature from a lake in Canada, from several streams or waterfalls in Wales, Cornwall, Scotland, Germany and Slovenia and many other places during seven decades . And yet I’m still here apparently.

Learn more about why the germ theory of disease might not be as compelling as you are led to believe at Reality of Illness