Natural Swimming Pools with David Pagan Butler (PVP071)

“If you want a really healthy water, you want it full of life; not devoid of life.” David Pagan Butler

Permaculture Voices Natural Pools


Americans love to swim. So much so there are 10 million residential pools and 300,000 public pools in the US; and from Memorial Day to Labor Day those pools open up and become a hub for activity.  BBQs, cannon balls, and Marco Polo are summertime staples in many areas making swimming the second most popular recreational activity in the US.

There is a romanticism around swimming, it is part of our more recent culture.  In 2003 in the NY Times Garbarino wrote “to most people swimming pools conjure summer afternoons dedicated to carefree indulgences like lime daiquiris and a satisfying bad novel. Pools are pleasure ponds and symbols of suburban arcadia.Source.

A true picture of summer, but what’s in all of those pools beside rafts, kids, party goers, and well…. pee?

Chlorine, and lots of it.

In an attempt to ensure that human beings are the only living things in the pool water, copious amounts of chlorine are dumped into each pool every day across the world.  It’s smelly, it’s sold in buckets with warning labels suggesting that you wear gloves and respirators while handling it – it is nasty stuff, for sure, but that is what we use because it is effective. It kills microorganisms.

Chlorine works on a scorched earth, or scorched water, type of approach.  Kill it all.

“Chlorine kills bacteria though a fairly simple chemical reaction. The chlorine solution you pour into the water breaks down into many different chemicals, including hypochlorous acid (HOCl) and hypochlorite ion (OCl). Both kill microorganisms and bacteria by attacking the lipids in the cell walls and destroying the enzymes and structures inside the cell, rendering them oxidized and harmless.” How Stuff Works.

If the chlorine is doing this to the cells of organisms within the water, what do you think that doing to the cells on your body?

Probably not good stuff.

Chlorine has known side effects of nausea, vomiting, burning sensation in the throat, blood nose, eye irritation, coughing, and skin itch and irritation.  These side effects can come from both skin to water contact and from the inhalation of vapors coming off of the pool water as the chlorine volatilizes.

Chlorine is effective, but the health issues are there, no doubt about it.

I don’t want to fear monger, but anyone who has swam in a chlorinated pool for an extended period of time has probably noticed at least some of these side effects.  I can remember as a kid looking at the lights after being in a pool for a while and seeing a red halo around the lights.  Not good.  My eyes hurt, they itched, they felt dry, obviously from the chlorine.  Now I am not a scientist, but I think it is safe to say that anything that hurts your eyes after an extended period of contact probably isn’t good for you in the long run; and I don’t seem to get those same eyes issues while swimming in a lake or the ocean.

It isn’t just me experiencing this or worrying about this.  Moms and the health conscious bloggers around the world love to hit on this topic talking about the dangers of good old chlorine in the water by aligning it to the poison gas used in WWI.  But it isn’t just the internet writing about this stuff and spreading unsubstantiated fear.  There is some science here and studies have been done.

In a study by Dr. Manolis Kogevinas in 2010 titled “Genotoxic Effects in Swimmers Exposed to Disinfection By-products in Indoor Swimming Pools” he came to the conclusion that “Our findings support potential genotoxic effects of exposure to disinfection by products from swimming pools. The positive health effects gained by swimming could be increased by reducing the potential health risks of pool water.” Source.

 If chlorine is so bad, why are we even using it?  Where did this whole idea come about?

Kevin Olsen from Montclair State University discusses the origins of chlorine in his paper ‘Clear Waters and Green Gas’..

In the late 1800s “bleaching powder, calcium oxychloride was made by treating chlorine gas with lime. The chlorine was supplied as a byproduct of the electrolytic production of sodium hydroxide. Passing an electric current through a concentrated solution of sodium chloride liberates chlorine and hydrogen gases and leaves behind concentrated sodium hydroxide, commonly known as caustic soda. It was, and still is, used in a great variety of industrial processes including soap and glass manufacture.”

“Anyone producing caustic soda needed to find a market for the chlorine byproduct. Each time there was an imbalance between the production of sodium hydroxide and the market for chlorine, chemists were set to work discovering new uses for the latter.”

“Credit for the first use of chlorine to disinfect potable water goes to the British scientist Sims Woodhead, who used “bleach solution” as a sterilizing agent during an 1897 typhoid outbreak in Maidstone, Kent. This temporary measure entailed introducing the solution at the distribution mains. The first regular use of chlorine for potable water treatment in the United States began at the Jersey City Boonton Reservoir in 1908. In 1914 the US Department of the Treasury promulgated the first bacteriological standard for potable waters in the United States.”

Municipalities had now found a way to sterilize their drinking water.  Dirty water was a big problem at that time and for right or for wrong this chemical treatment helped stop the spread of a lot of disease.

At that same time in the early 20th century public baths and pools were becoming popular as a way to promote good hygiene. There was only one problem.  The people getting into these pools were dirty.  And the risk of diseases like typhoid, cholera, and dysentery were high (that’s why they wanted to clean up the water supply in the first place).  Now you have these pools where you are trying to get people clean and promote fitness, but these pools closed bodies of water.  What goes in, don’t come out. There is no filtration happening here.  Whatever goes into the pool on the body of a dirty person (they were dirty – let’s be honest about the time period) more or less stayed in the pool.  That made for some pretty dirty water that wasn’t devoid of organisms living in it.  And those organisms weren’t the ones that you wanted living in the water.

So now you have all of these closed bodies of water known as pools, and how do you clean the water and keep these pools ‘safe’? There was no sterilization or filtration at the time for pools, so one of the solutions at the time was to just drain the pools and just put new water in them periodically.  Can you image that?  Effective, but a pain.

That changed in 1911 when John Wymond Miller Bunker started doing experiments at Brown University’s Colgate Hoyt Pool. He began to measure bacterial counts in the pool and then began adding chlorine, taking measurements. “Surface bacteria counts fell from 500 to 30 in only 15 minutes, to 10 in 30 minutes, and “complete sterility” after an hour. According to the Times report, the pool remained sterile for four days. […] The news item went on to report that there was “no odor and no perceptible taste.” The report concluded by saying “hypochlorite (sic) of lime is an effective sterilizer of swimming pools .”  Source.

From then on chlorine became the standard for swimming pool sterilization.  And not much has changed since then.  The delivery system is different, but for the most part, chlorine does most of the heavy lifting when it comes to pool water sterilization.  And by chlorinating the water pool mangers opt for the sterility approach.  Create the conditions for life not to happen.

But there is another option for creating clean water. And that water isn’t sterile. As my guest today David Pagan Butler of says, “If you want really healthy water, you want it full of life; not devoid of life.”

That is what today’s show is about.  Creating the conditions for life to happen within the water in natural swimming pools. Natural swimming pools unlike their chemical counterparts use no chemicals.  The pool water is cleaned biologically by plants and organisms within the water.  No smells, no chemicals, no pathogens, biology creating water so clean you can drink it.  

David has developed a system of building natural pools that is both cost effective and ecologically enhancing.  Natural pools that utilize natural biological processes to keep the water clean.  The classic case of nature doing something equal to or better than some chemical made in a factory – clean, pathogen free drinking water, in swimmable form.

Technically pools, these pools are a far cry from the blue lined or concrete lined pools that you are used to.  These pools look like the pristine ponds that you would expect to find in the countryside – fully functional and full of life, yet totally swimmable and manageable for any homeowner.  Natural looking enough to fit within any permaculture landscape, yet eco-chic enough to make it into any spread in Architectural Digest or Dwell.

In a Clorox world these pools are a welcome return to nature; natural habit that provides functional use for us as human beings, no chemicals involved.

Get out the wish list pad because I am pretty sure that after this interview, building a natural pool will go onto the list.

Natural Swimming Pools with David Pagan Butler.



  • “What we are after is creating a healthy ecological system.”
  • “If you want really healthy water, you want it full of life, not devoid of life.”


Key Points relating to Natural Swimming Pools:

  • Air pumps enhance natural filtration and circulation.
  • Natural pools are isolated from the ground water.
  • Keep the water less than 30 degrees C, so if you have higher water temperatures then you need more deep zones.
  • No fish.  Fish eat daphnia (which you want) and add nutrients to the water which can lead to algae.
  • The goal is to try to keep nutrient levels low and keep as much life in the pool as possible.
  • The greater the amount of water in the system, the more stable the system is.  Less water means less biological inertia.
  • The planted zone should be greater than or equal to the area of the swim zone.  At least 50% of the area dedicated to plants.



Natural Swimming Pools

Swimming in a Natural pool among flowering plants of lilies, iris and marsh marigolds is a celebration of life. Soothing your limbs and mind and skin and eyes, it seems every cell in your body is telling you – this is the way swimming should be. Natural Pools work entirely with nature to provide hygienic water for swimming.

This pool is about 180m2 in total. The central swimming area is 4.5m x11.5m and 2.2m deep. It took me a couple of years of weekends and days off to complete and cost around 6000GBP.  via Organic Pools


Image: David Pagan Butler -

Natural Pool.  Image: David Pagan Butler –

Plunge Pool

The plunge pool is a proper organic pool (natural swimming pool), only smaller. And this one is small enough to fit in a modest garden to bring the delights of plunging into organic water to more of us.

My kids love this pool; they feel comfortable learning to swim in deep water knowing they can reach the shallows with a single kick of doggy paddle and an outstretched arm. It is somehow manages to achieve being simultaneously cottage garden cosy and yet a sparkling wilderness.

This pool covers an area of 48 square metres (6mx8m) with a 2.2m deep swimming or plunging zone measuring 4 metres by 2 metres. Come on one of my courses and I’ll show you how you can make this organic pool.  via Organic Pools

Image: David Pagan Butler -

Plunge Pool. Image: David Pagan Butler –


How Organic, Natural Pools Work

The nutrient level in an organic pool is carefully restricted so competition for the limiting nutrient (usually phosphorous) is fierce. In these circumstances, pond plants outperform algae, keeping it suppressed and barely hanging in at the margins. A pond, low in nutrients, is a healthy environment for wildlife. An organic pool is teeming with life. If an alien micro-organism, a human pathogen for instance, enters the water, it faces battalions of hungry pond dwelling micro-organisms to either starve it out of existence, or devour it. A water analysis of this pond water showed that it contained zero organisms of e coli. per litre of water.  More information on David’s site.


Organic Pools DIY Manual – Free Download Version – Download HERE

This is a practical step by step guide to build your own Natural Swimming Pool. It is designed to accompany my film “Natural Swimming Pools: A Guide to Building your Own” which is available on DVD from

There are many ways of creating a Natural Swimming Pool, but I want to show you a way that is simple to construct and works perfectly. From there, you can adapt it to fit in with your own ideas. This is a practical guide to get more of us started on building these pools. To date, there is no[other publication that provides this information. Indeed there are many people who would have you believe this is too complicated for the non[professional. That is nonsense. I want to show that this project is hard work but deeply rewarding and completely achievable, and along the way we’ll bubble a few more myths out of the water. 

Natural Pools

Download the free guide HERE


David’s Courses, DVDs, and manual on Natural, Organic Swimming Pools:

Organic Pools Course

DIY Organic Pool DVDs and Manuals

book cover full version small2


How To Build a Natural Pool – DIY Organic Pool Build

The Plunge Pool – Possibly the Smallest Natural Swimming Pool

Natural Pools – Building Your Own Organic Pool

Natural Swimming Pools – BBC Inside Out




For more on David Pagan Butler & Natural Pools visit:

David’s site: Organic Pools

Natural Pools on Facebook

David on YouTube

You can contact him via Organic Pools HERE.





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Comments 5

  1. Trapping the water that might be lost through evaporation with a cover, simply makes great financial sense. Also, if you use a cover and slow down the rate of evaporation, you may also be able to cut down on the amount of chemicals used to keep the pool water clean — why?

  2. I’m trying to build a public natural swimming pool in Southern China and have done a few test ponds. I’ve recently noticed a miniscule (1-2.5mm) vigorous, wriggler. It is a sort of nematode. There is a type of this flat worm that use snails as immediate hosts and the free swimming adults can lay eggs through the skin of human bathers and internally infect them. How can this problem be treated in endemic locations? We were really excited in making this a dream come true, but is there no way to swim in natural freshwater in certain places? Did people that use to jump into the lakes and rivers around here carry infections with or without recorded harm?

    1. Post

      That is a good question and I don’t know the answer. I think it a case where a bunch of research is required if that is a worry.

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