It took me longer than it probably should have to understand the sanitation puzzle.
I have been working with sanitation for years, and I have a slightly embarrassing confession.
For quite a long time, I thought I was working with low-flush toilets.
Then I thought I was working with sanitation.
Then I started understanding what poor sanitation really means for people: diarrhoea, intestinal worms, cholera, children missing school, families spending money on treatment and, in the worst cases, children dying from diseases we already know how to prevent.
Then wastewater entered the picture. Then nutrients. Then agriculture, soil, rivers, oceans and public health.
And of course climate change came along and made everything more complicated. Drought means less water. Floods spread contamination. Extreme weather can knock out systems that were already struggling. Changing rainfall puts pressure on water supplies, agriculture and food security.
For a long time, these sat in my head as separate problems. A toilet problem. A water problem. A health problem. An agriculture problem. An ocean problem. A climate problem.
I started thinking of them as pieces of the sanitation puzzle.
I could see the individual pieces quite clearly. What took me much longer was seeing the picture.
Maybe I am just slow.
But eventually the pieces started clicking together.
A toilet in a school can become a groundwater problem. Groundwater can become a drinking-water problem. Contaminated water can mean diarrhoea or intestinal worms in a child. Nutrients leaving that same toilet can travel into a river, feed algal growth and eventually become an ocean problem. Then a flood can spread the whole mess through a community in a few hours.
But those same nutrients tell another story.
Treat them properly, keep the pathogens away from people and return the nutrients to soil, and suddenly what we called waste is helping us grow food. The food gets eaten, the nutrients pass through us, and we are back at the toilet again.
That was when I stopped seeing a line. I started seeing a loop.
And one connection made the whole thing almost ridiculously simple:
Fish hate it. Soils love it.
Nitrogen and phosphorus are essential nutrients. Farmers buy them because plants need them. Put too much into rivers, lakes and coastal waters and they become pollution, feeding algal growth, reducing oxygen and damaging aquatic ecosystems.
Put those same nutrients safely into soil, in the right amounts, and they help grow food.
Same nutrients. Wrong place: pollution. Right place: fertiliser.
Now look at what we often do.
We mine phosphorus. We manufacture nitrogen fertiliser using huge amounts of energy. Farmers buy those nutrients and grow food. We eat the food and the nutrients pass through us.
Then suddenly we stop calling them nutrients. We call them waste.
We take beautiful drinking water, mix our shit and piss into it, pump the cocktail through kilometres of pipe and spend serious money and energy trying to remove those nutrients before they reach rivers or the ocean.
Meanwhile, somewhere else, a farmer is buying nitrogen and phosphorus.
When you explain the system slowly enough, parts of it sound slightly bonkers.
That is circular stupidity with engineering drawings.
The question for me changed from How do we get rid of human waste? to something much more interesting:
How do we keep pathogens away from people while keeping water and nutrients useful?
Once I started asking that, I saw the connections everywhere.
The ocean starts on land
Take Hawaii.
Most of us think of blue water, beaches, coral reefs and those sunset photographs that make you wonder why you are sitting in an office.
But underneath the postcard is a sanitation problem.
Hawaii still has around 88,000 cesspools receiving untreated sewage and releasing it into the ground, where pathogens and nitrates can contaminate groundwater, streams and the ocean. Groundwater also provides most of Hawaii’s domestic water.
Suddenly a toilet inland and a coral reef offshore are part of the same story.
It sounds obvious once you see it. It wasn’t obvious to me at first.
Ocean protection doesn’t start at the beach. It starts in homes, schools, hotels, clinics, farms and settlements. Waste moves through soil, groundwater, rivers, stormwater and wastewater systems until somebody downstream gets the consequences.
The ocean did not create the problem. It just received the invoice.
That is the part we miss when we put water, sanitation, agriculture and the environment into different boxes.
Nature doesn’t have boxes. We do.
Water people. Sanitation people. Agriculture people. Health people. Climate people. Ocean people. Different ministries, different budgets, different conferences and an impressive amount of PowerPoint and piles of reports.
Nature doesn’t care. Nature runs one system.
We built systems that separate responsibility, but nature connects the consequences.
The toilet is only the user interface
Another piece of the puzzle took me a while to understand.
We spend an enormous amount of time talking about toilets. I understand why. Toilets are visible. You can design them, manufacture them, install them, photograph them and cut a ribbon outside them.
There are some fantastic new toilet technologies. Some use almost no water. Some separate urine. Some treat waste on site. Some are incredibly clever and very expensive.
I love innovation.
But a clever toilet on its own solves surprisingly little.
The difficult part comes afterwards.
Who cleans it? Who maintains it? Where does the shit go? Who collects it? How is it transported and treated? How do we know the pathogens are dead? Who pays? And what happens when something breaks three years after the pilot funding and photographers have disappeared?
A toilet that works on opening day is easy.
A sanitation service that still works five or ten years later is the achievement.
That is why I increasingly think of the toilet as the user interface. Behind it has to be containment, collection, transport, treatment, maintenance, financing, regulation and safe reuse or disposal.
Miss one of those pieces and we haven’t solved the problem.
We have just moved the shit.
Sanitation is not a gadget. It is a service.
And if we design that service from the beginning, we can choose the toilet based on what the whole system needs rather than installing hardware first and asking somebody else to solve what comes out of it later.
The future is a toolbox, not a religion
This is also where sanitation discussions can become strangely religious.
Sewers versus non-sewered sanitation. Centralised versus decentralised. Flush versus dry.
I don’t think the future looks like that.
Sewers are brilliant infrastructure where they make sense. Dense city centres will continue to need them and large wastewater treatment plants.
But a rural school does not necessarily need the same solution as central Cape Town, Stockholm or New York. A water-scarce community may need ultra-low-flush toilets and source separation. A flood-prone settlement may need sealed systems. A coastal village may need a solution designed around protecting groundwater and the ocean. A farm community may be perfect for local treatment and nutrient recovery.
Conventional sewers have a place. Container-based sanitation has a place. Urine diversion, water reuse and decentralised treatment all have a place.
The clever bit is knowing which tool belongs where.
The future is a toolbox, not a religion.
And once we start thinking that way, sanitation becomes much bigger than a municipal cost.
Design the whole cycle properly and sanitation protects public health. Use less drinking water and it helps water security. Treat the waste properly and fewer pathogens and nutrients reach rivers and oceans. Recover nutrients and agriculture gets something useful back. Reuse water where appropriate. Create local collection and treatment services and you create local jobs. Design for droughts, floods and power failures and you build climate resilience.
Suddenly sanitation is connected to health, water, food, agriculture, oceans, jobs and climate.
Which, of course, it always was.
We were the ones who separated it.
The latest WHO and UNICEF numbers are a pretty brutal reality check: around 3.4 billion people still lack safely managed sanitation, 2.1 billion lack safely managed drinking water and 1.7 billion lack basic hygiene services.
In 2026.
That doesn’t mean conventional systems have failed. Where they work, they can work extraordinarily well.
But it should make us question whether simply copying exactly the same model into every informal settlement, rural village, island, rapidly growing African city and water-scarce region is really the plan for the next fifty years.
Maybe not.
Our Edison moment
This brings me to what I have started calling our Edison moment.
We remember Thomas Edison for the light bulb.
But a light bulb on its own isn’t terribly useful. You need electricity generation, cables, distribution, switches, meters, maintenance and a business model that allows somebody to turn the damn thing on.
The revolution wasn’t really the bulb. It was the system around the bulb.
I think sanitation is approaching the same moment.
Our breakthrough will not be one magic toilet, one magic pipe or one shiny treatment technology that wins an award and looks fantastic on slide number 17.
We have had enough magic boxes.
The breakthrough comes when we finally see the whole circuit.
Water connects to sanitation. Sanitation connects to health. Human waste contains nutrients. Nutrients connect to soil and food. Badly managed nutrients connect to rivers and oceans. Climate change puts pressure on the whole lot.
Break one connection and the damage appears somewhere else.
Get the system right and the benefits spread everywhere: cleaner water, healthier children, fewer nutrients in rivers, more nutrients in soil, less pressure on freshwater, healthier oceans, more resilient communities and more local jobs.
For years I thought I was working with low-flush toilets.
Then sanitation.
Then water.
Somehow agriculture, health, oceans and climate walked into the room.
Eventually I realised they had been there all along.
I just hadn’t put the puzzle together yet.
Maybe everyone else figured this out years ago.
It took me a little longer.
But now I can’t unsee it.
Hell, everything is connected.
And perhaps the next infrastructure revolution starts when we stop solving each piece separately and finally design the whole damn puzzle together.
