He shows up, he’s clearly one of us, and then he disappears into a fog of half-answered questions.

If I had to assign that adjective to a single step in a desalination plant, it would be the DAF.

A quick caveat before we go further: here we’re talking only about seawater desalination plants. Dissolved Air Flotation has a much clearer, more settled role in specific industrial water treatment applications. In desal, it lives in a grey zone in my opinion sometimes.

The range of opinions you collect from water professionals about this system is so wide that it’s genuinely hard to write about cleanly.

So I’ll do my best to give you the context around the unit that causes so many headaches.

As always in our world, understanding the root cause behind each piece of feedback is a case-by-case exercise — same region, same intake water, and yet two clients (or the consultants who wrote their specifications) will reach opposite conclusions.

And if you don’t install a DAF — what are the risks, and how badly do they hit the business model when things go wrong?

Last week at Euromed in Marrakech, I really enjoyed moderating the session with Alexander Baekelandt from SeQual, winner of the Innovation Award.

We talked about “predicting tomorrow to act today”. A great example is forecasting an algae bloom so operators can switch on the DAF system before it is too late.

As you can read later, it is not simply a matter of turning it on or off.

This predictive capability provides added value by giving operators the time they need to respond, making it the kind of insurance every desalination plant should have.

Listen to some feedback I got and you’ll hear two camps:

• “It doesn’t really work once you’re in operation. It’s bypassed most of the time, and when you finally need it, it hasn’t been maintained — or you discover it can’t go from 0 to 100 in one second, it needs time to stabilise.”

• “It should be running permanently, because it protects the RO downstream and saves you when conditions turn.”

Both camps are right, depending on the plant. That’s exactly why the DAF is the mystic.

Read more

A lot of you in our community have been reaching out as startup founders. With your recent influx of queries and feedback, I can feel how challenging the journey is.

To support this, I’m organizing a joint session with a few of you to spotlight your initiatives, visions, struggles, and current needs with our broader audience.

I’m also adding these to our knowledge hub to keep track of compelling projects moving forward (though we aren’t trying to become a dedicated tech hub).

With so many of you looking up to Paul as a global benchmark for water innovation, this feels like the right time to reshare this conversation. I know it will inspire you.

Beyond that, remember you can always lean on the BlueTech Research team for your specific cases and gain some actionable intelligence. They have an amazing crew (links at the end of the essay), who are exactly the kind of professionals you want in your corner.

I’m also sharing a couple of interesting job openings BlueTech posted a few weeks back. Check them out if you’re looking for your next step!

I recently came across an email from David Serna, and I loved his approach of compiling a section with his favourite ideas from a conversation. So, I have adopted a similar format for this case and included it at the end of the essay. I feel it is also a great way to reflect on and capture the essence of our episodes, especially for those who may want to dive deeper into the full video, which is available above as usual.

Every person in water has a water story

Paul O’Callaghan’s begins on a small island off the coast of Cork, where he swam in a body of water clean enough to build rafts on, until, in the mid-1980s, it wasn’t.

Ireland had no wastewater treatment to speak of, and a kid who had grown up trusting that water decided to do something about it.

That instinct took him through the rainforests of Malaysia with a machete and a botanist (I was thinking of generating an AI picture about this, but I’ll leave it to your imagination ;), into a biochemistry degree, and eventually into the greenhouse of a Body Shop wastewater plant, where a “living machine” of plants treated the runoff of shampoos and body washes.

He still remembers the smell. Earthy, sulfurous, perfumed. He calls it the alchemy of water, and says he never fell out from under its spell.

I bring up the origin story because it explains everything that follows.

The founder of BlueTech Research is, before anything else, a practitioner who climbed down into the tanks.

And when a practitioner spends two decades watching water technologies try to make it from a jar on a lab bench to a line item in an EPC contract, he learns something the rest of us need to hear: there are no shortcuts. There are only fewer mistakes.

The S-curve nobody can cheat

Ask Paul how long it takes to commercialise a water technology and he walks you through the stages with the patience of someone who has watched it happen a hundred times, and I learnt in detail in his latest book that I absolutely loved.

It starts with someone in a lab, a small jar, a test, a measurement.

Then comes the rig — a few lengths of PVC pipe and some valves — taken out to be tested in real-world conditions.

That alone can eat two or three years before usable data comes back.

Then you build a full-scale unit. Then another.

By roughly the third full-scale installation, you’re finally ready to standardise; generation four is usually the one that works the way the brochure promised.

And even after you have a proven, standardised technology, you wait again — another six, seven, eight years — for consulting engineers and EPC contractors to trust it enough to write it into a tender.

• Trust, very important.

As someone who sits on the EPC side, this landed hard for me.

I’ve turned away good technologies at my own table, not because they didn’t work, but because they weren’t on the approved vendor list or didn’t have the references.

Paul’s point is that this isn’t dysfunction. It’s physics.

What you can do is make fewer mistakes, because every mistake adds to the timeline and burns money and time you don’t have.

That is the entire value proposition of being a careful operator in this industry. Speed is mostly an illusion. Discipline is real.

You simply cannot force a natural process to move faster than it can. That’s why time is the ultimate moat, it creates a natural barrier that protects those who are willing to keep compounding over the long haul.

Why more money doesn’t buy more speed

The corollary is the part investors least want to hear.

The thesis is sound. The execution fails on timing.

A company raises at a great valuation on a great story, revenue-positive in four years, easy.

Four years later it’s revenue-generating but not revenue-positive, the next round reprices it, and the original investor either gets diluted or walks.

The deeper trap is believing that more money buys proportional speed. It doesn’t.

You need capital to survive, but there are rate-limiting steps in scaling physical water infrastructure that simply don’t care how much is in the bank.

Triple the funding and you might go fifteen or twenty percent faster, not twice as fast.

So the two qualities that actually matter, Paul argues, are patient money and smart money.

And when a VC pulls the plug at year seven or eight, that’s often not the end of the story, the founder is usually so committed that they carry the IP onward into the next vehicle.

Companies die; the technology and the people frequently survive.

The market is consolidating and quietly opening up

The water wheel is always turning. Over twenty years, Paul has watched the number of water-tech startups stay roughly constant while the quality climbed sharply, they’re smarter and better than they used to be.

At the same time, consolidation has reshaped the top of the market, with the big platforms rolling up membrane and solutions businesses, while a stubborn gap persists in the mid-market.

Two shifts stand out.

First, the move from single-technology vendors to integrated solutions providers, increasingly bundled with operational, service contracts.

The logic is the complexity of water itself: selling someone an end-of-pipe wastewater plant is one thing; helping them reuse that water for clean-in-place, boiler demineralisation, and rinse loops is a holistic problem that pushes buyers toward integrated partners.

Second, large industrial corporates are now willing to sidestep the big players to work directly with startups on moonshots.

We didn’t see this before; the old world was framework agreements, three approved vendors, an RFP, an EPC contract.

But when a company needs to do something genuinely new, the appetite changes.

That collaboration between corporates and startups, around capabilities the conglomerates don’t yet hold, may be the most interesting trend in the sector right now.

Kill your darlings early

The hardest lesson in the conversation came from Brave Blue World, the documentary Paul produced.

The first shoot, in Singapore, felt great, and then they reviewed the footage and realised it wasn’t going to scale. It had the feel of a television interview, not a story people would carry with them.

This is the sunk-cost fallacy (we can list endless examples probably in our daily jobs) in its purest form: you’ve come so far, what do you do?

They chose to throw a great deal of that material away, go back, and redesign the project from the ground up, and they made that call early.

That decisiveness is why the film eventually worked, why it found a director who took them to Kenya, India, and Mexico, and why it ended up on Netflix with Matt Damon and Liam Neeson.

By the way, I have a direct message from Matt Damon to all of you.

Just kidding!

In all seriousness, though, every single one of us can help. If you aren’t ready to invest $5 a month in a premium subscription to The Water MBA, that’s completely fine, but consider donating that same amount to Water.org instead.

You, too, can make a meaningful difference.

Anything is possible

When I asked what corporates most need to learn, he gave me a sentence: anything is possible.

L’Oréal didn’t believe a water-loop dry factory was achievable until they built one — and now every L’Oréal factory will be one.

Intel set audacious 2030 water goals and hit them ahead of schedule.

When Microsoft presented its progress recently, jaws dropped at the pace.

They came from people arriving with a fresh outlook and refusing to accept the assumed timeline.

That, in the end, is what keeps a man surprised after twenty-five years in a sector he supposedly knows cold.

Paul started as a wastewater and biosolids specialist; with every move his aperture widened, until he arrived at a genuinely radical reframe of the whole practice.

Our job, he argues, is to leave water in nature.

Reduce leaks, capture industrial water, explore atmospheric water capture, and you leave more in the green water cycle, where it slows down, purifies, and regenerates. Invert the equation and the engineering looks different.

The thread running through all of it is a beginner’s mind. Paul owns a library of books on water and still, by his own account, gets surprised all the time.

For a platform built on the conviction that we always have something left to learn, I can’t think of a better note to end on.

Never be afraid of being challenged, he told me, and never hang on too tightly to your beliefs.

That’s the whole curriculum, really.

My favorite ideas from the conversation with Paul O’Callaghan

On the Alchemy of Water

I was fascinated with the alchemy of water and the sensory nature of it — you’re feeling the humidity on your skin, you’re smelling it, but you’re also looking at science in action.

I fell under the spell, and I’ve never fallen out of it.

On Working With Good People

If you work with good people, good things happen. That’s an immutable law.

If you’re working with smart people who share that passion and know why you’re doing the work, you have fun doing the work.

On Why Water Innovation Can’t Be Rushed

The third house you build is the house of your dreams — not the first one.

I don’t believe you can shorten it. What you can do is make fewer mistakes.

A mistake is adding to the timeline. It’s a waste of money, it’s a waste of time.

On Not Being Left Behind

I don’t want to be left behind. I don’t want to be the last person selling a PVDF membrane when PFAS compounds have been outlawed and everyone’s moved over to ceramics.

That’s our role — getting your binoculars so you can see a little further over the horizon, maybe see around a corner to any potential disaster, and avoid making a mistake.

On Patient Money and Smart Money

There’s patient money, and there’s smart money.

It doesn’t go twice as fast because you have twice as much money.

When you see failed companies, it correlates with a misalignment between the expectations of the investor — both in valuation and in timeline.

On the Sunk Cost Fallacy

There’s a thing called the sunk cost fallacy. You’ve gone so far — what do you do?

We were prepared to lose a lot of that material, because we were going to go back, redesign, and rethink the project. And I’m glad we did.

On Anything Being Possible

They came in with a fresh outlook and said: anything is possible. And before you know it, there’s half a dozen projects.

On Leaving Water in Nature

Our fundamental job is not to take water from nature — it’s to leave water in nature.

If you leave water in nature, nature creates water. If you leave water in nature, nature slows water down.

We’re not running out of water. We can create water abundance.

On Staying Surprised

What keeps me motivated is continually being surprised.

I’ve got a lot of books on water, but I continue to be surprised all the time.

Have a beginner’s mind. Never be afraid of being challenged, and never hang on to your beliefs.

Meet and follow-up closely Bluetech Research Team:

Lily Chen, I like the conversations she brings to the table in Blue Notes Pod.

Saurabh Singh, he’s one of the few that I activated a ring bell in LinkedIn to make sure I receive notifications when he publishes something, because among all the stuff out there, I feel it is authentic and valuable for me.

Paul O’Callaghan, no need much more introduction.

Interesting career opportunities for Research Analyst and Key Account Manager.

For most of my career, the number I (and probably you) carried around was: 70% agriculture, 20% industry, 10% domestic.

That’s the textbook split of how humanity uses freshwater, and it isn’t wrong.

But averages are liars.

I live in the Guadalquivir basin. Here the split is closer to 90% agriculture, 5% domestic, 5% industry.

Agriculture isn’t a slice of the pie, it is the pie.

Then, a few years ago, I learned that Singapore looks nothing like this: almost no agriculture, demand dominated by industry and households (read later the policy innovation about water reuse recently announced…)

Same planet, same molecule, a completely different economy of water.

That’s the moment my brain got rewired.

That sector is industry. Industry is a different animal.

It doesn't use the most water. But it has a balance sheet, a cost of capital, a board that understands risk, and a reason to act now.

That combination is rare in water, and it changes everything.

While these financial interests ensure that capital flows, the shift from standard financing to “projectification” also carries distinct risks for our business, as detailed at the end of this essay.

Read more

This time deliberately step off the technical ground. Not membranes and treatment trains, but commercial and market intelligence.

What does the market expose about reuse that the process flow diagram never will?

As usual, I go back to one of my favourite sources.

Partly because some of these people I almost consider good friends, they’re genuinely great peers, and I just like listening to them.

Some time ago I had dinner with Keith Hays, one of the co-founders of Bluefield Research, here on this side of the Atlantic, and the kind of work they do has always fascinated me.

At the end of this publication, you’ll find links to these contacts. They regularly share extremely interesting perspectives and genuine value on LinkedIn. I wish I had more time to consume all the great content the share out there, and I’m sure I’ve missed many, but I highly recommend connecting with and following them.

The Future of Water podcast is also one of my regular check-ins every couple of weeks, usually while I’m at the gym (pretending I do exercise). It consistently offers valuable insights and thought-provoking conversations. Highly recommended.

So in this conversation with María Cardenal, from Bluefield’s Barcelona office, to talk reuse.

The invisible craft behind the data

Most of us in this sector spend our days heads-down inside our own scope.

I know I do, a purchase order lifecycle here, a commissioning sequence there, one brine outfall…

We start to believe the work just arrives on our desk. It doesn’t.

Behind every clean number in a report there’s an enormous amount of invisible labour: understanding the market, sizing it, separating the big players from the small ones, working out who is operating where and why.

It runs on a subscription model with a database layer (the Data Navigator, which Keith first told me about) that clients filter and query.

The geographic core is the US, Canada and Europe; the verticals run from municipal water to industrial — pharma, beverage, meat, metallurgy, mining, and increasingly water for data centres and energy — plus a whole digital-water practice.

What I found most honest was when I asked María about the hardest part of her day-to-day.

Her answer wasn’t glamorous: it’s finding the information.

There’s a lot of it out there, but it’s scattered, hard to digest, hard to interpret, and sometimes it simply isn’t there at all.

She described disappearing down a rabbit hole — Alice in Wonderland, in her words — pulling thread after thread, then doing the sanity check with peers to make sure the conclusion holds.

Actually, it is quite a similar operating system to creating The Water MBA.

Reuse is a market, not a technology

Here’s the conceptual shift that runs underneath everything: the wastewater plant is no longer a treatment endpoint.

It’s becoming a provider — a source of water, of energy, of recovered resources.

Once you see it that way, reuse stops being an engineering question and becomes a market question.

María laid out a clean four-part framework for why reuse actually happens in a given place:

• Drivers — environmental: water scarcity, the need to conserve water (potable or agricultural), and protecting coastal aquifers from seawater intrusion.

• Regulatory requirements — the macro frame. The EU Water Reuse Regulation (2020/741) has applied directly across all member states since June 2023, setting harmonised minimum quality standards for reclaimed water in agricultural irrigation. On top of it, the recast Urban Wastewater Treatment Directive (2024/3019), adopted at the end of 2024.

• Local requirements — infrastructure, technical capacity, and geography. Reusing water halfway up a mountain (pumping uphill, burning energy) is a different proposition from a coastal industrial cluster where the user is next door.

• End use determines treatment — and this is the commercial crux. Agriculture, street cleaning, industrial cooling and potable reuse each need a different treatment level. There is no single right answer.

Notice what’s missing from that list: “build the best plant.” The commercial lens reframes the whole problem.

The numbers: leadership is relative, headroom is enormous

Back in 2023 Bluefield went so deep on European reuse that one report had to become two, covering 11 countries.

Their estimate for the total European water-reuse market over 2023–2030 was around €1.8 billion.

The headline most people expect is that Spain leads Europe, and it is correct. The country reusing the most water on the continent.

But here’s the figure that should keep us humble: that leadership amounts to reusing only about 14% of our wastewater.

The European “leader” is leaving most of the resource on the table.

Within Spain it’s wildly uneven — Murcia reuses something like 98%, almost all of it for agriculture, a number you simply don’t see anywhere else.

So “leader” is a relative word, and the more useful way to read those numbers is as headroom.

Layer in Bluefield’s map of incremental water scarcity — the regions sliding into stress on current climate trends — and the addressable market isn’t just deep, it’s geographically expanding.

Places like Málaga, already squeezed between population, tourism and climate volatility, are tomorrow’s mandatory adopters.

Belgium: where intelligence beats intuition

If you want to see why market intelligence earns its fee, look at Belgium.

Intuition says reuse is a Mediterranean story, sun, drought, fires.

Belgium has none of that branding, no specific reuse regulation on the books, and rain almost every day. And yet it sits in the top tier of the European reuse ranking.

Why? Because the country is under genuine water stress despite the rain, heavy urbanisation and industrialisation mean the soil simply can’t retain what falls, and the aquifers are limited.

And crucially, the demand is being pulled by industry, not policy: reuse around the Port of Antwerp, automotive plants near Brussels running closed loops for cooling and cleaning, potato-processing lines that drink enormous volumes of water.

One car factory near Brussels co-financed the reuse project that connected the local treatment plant to its site.

The lesson is one of the most commercially important in the whole topic: regulation is one driver, not the driver. Industrial demand and plain economics can lead reuse forward in a place no policy map would have flagged.

If your intelligence only tracks regulation, you’d miss Belgium entirely.

Los Angeles: the masterclass

LA has been at this since the 1980s. Not a ten-year sprint; a forty-year programme.

Bluefield frames US reuse as a five-rung maturity ladder: no reuse and drawing on natural sources; non-potable reuse; indirect potable reuse (IPR); studying direct potable reuse; and finally approved direct potable reuse.

LA runs the full stack and does three things at once:

1. Industrial supply — reclaimed water piped to refineries and industry instead of potable water.

2. Irrigation — parks, golf courses, stadiums, urban green space.

3. A seawater intrusion barrier — injecting reclaimed water into coastal aquifers to physically hold back the saltwater that creeps in as those aquifers are drawn down. It’s the same risk Barcelona lives with, solved with reused water.

I love that detail, because it captures the part of this business everyone underrates: it’s mostly invisible.

The plants aren’t in the city centre, the pipes are underground, and then someone tells you the water you flushed is coming back to irrigate the food you’ll eat.

Of course the public hesitates. That’s why IPR and DPR are 20-to-30-year programmes built on pilot after pilot, redundancy after redundancy, and patient confidence campaigns.

The technology is the easy part. Trust is the slow part.

The four commercial truths

Here’s what the market actually exposes as per Maria point of view:

1. Infrastructure is the cost, not the technology. We obsess over treatment, but the pipe that redirects the water to a user who can actually take it is often the bigger line item. That Belgian factory paid for the connection, not the treatment.

2. There is no one-size-fits-all — and over-treating is a mistake. Pushing every drop to potable grade is inefficient if it’s only cleaning streets.

   Higher treatment means more capex, more opex, more energy. Matching grade to use is the business model.

3. Who pays is the hardest equation in the room. Public and private benefits are tangled together.

   The intangible upside is real — freeing potable water for human use, enabling local industry, ESG and corporate water targets, lower emissions from industrial closed loops — but it’s genuinely hard to put on a single business plan.

   PPPs, incentives and reuse tariffs exist precisely because no one party captures all the value (you’ll read a great piece about this on next Tuesday)

4. Time is the price of entry. These are inter-generational assets. Anyone hoping to walk in, hit one technical key and flip the market is in the wrong business. We’re building for the next generation — which, by the way, is also why the demand is almost guaranteed for us :)

See you soon

The commercial reading is simple to state and hard to execute: scarcity sets the floor, regulation sets the frame, but industrial demand, infrastructure financing and public trust decide who actually builds.

That’s the part the membrane datasheet will never tell you, and the part people like María and the Bluefield team spend their days, heads-down in the rabbit hole, working out.

My thanks to María Cardenal for sharing it so generously, and to Keith and the wider Bluefield team.

The real privilege of our community is the peers and friends who’ll sit across a dinner table and tell you what the data actually says.

If you’re heading to Marrakech, come find me. Let’s talk reuse!

Continue on your own through the next sources:

Maria Cardenal, Antonio del Olmo, Keith Hays, the Bluefield website, and The Future of Water Podcast.

I couldn’t attend the event Global Water Summit 2026 myself. However, I spoke with several attendees, received a number of messages, and came across a few presentation slides.

I haven’t had enough time to fully analyse the event, so instead of sharing **10 things to know, I’ve focused on the five topics that stood out most to me.

**As a tribute to the well-known “10 Things to Know” format from GWI founder Christopher Gasson.

1. The finance gap is not a footnote

Read more

For thousands of years, humans made fresh water from the sea by boiling it. The Greeks did it on their ships; even the builders of the pyramids understood the trick.

Then, sometime around the 1980s, we replaced that thermal logic with a membrane and a pump, and the cost of water began its long fall.

It is salt, minerals, and a new way of thinking about the sea itself.

Guillem is a doctor in chemical engineering, a researcher who has put close to thirty products into the industry over his career, a university professor, and a board member of the European Desalination Society.

But the most revealing thing he said about himself was not on his CV. It was a philosophy of how innovation actually happens, and a refusal to romanticise the lab.

R&D is a conversation, not a cathedral

Ask most people to picture research and development and they imagine a quiet laboratory, a brilliant mind, a breakthrough.

Guillem’s picture is almost the opposite. The lab matters, yes, but the real work happens outside it, in conversation with customers.

The danger he describes is the “ivory tower” researcher — the one who decides, alone, that an idea is brilliant, pours years and money into it, and finally delivers something nobody wanted because it solved no real problem.

His antidote is almost embarrassingly simple: get out of the lab, go on the customer visits, listen at conferences, and let the voice of the customer shape the work.

I felt this in my own bones. When I launched The Water MBA in 2023, what I imagined in my living room mattered far less than the feedback the market kept sending back. You iterate toward fit, or you build a monument to your own assumptions.

This matters even more in water because of the rhythm of the industry. Compared to consumer electronics, water is conservative — and rightly so.

It is heavily regulated, it touches human health, and it runs on capital-intensive assets that nobody rebuilds on a whim.

So the clock runs slowly. By Guillem’s reckoning, a marginal improvement — a bit more membrane area, a little less energy, some antifouling character — takes around two years. Something genuinely new takes three to four.

The brine valorisation membrane his company launched this year traces back to an idea floated at a conference in 2022. Four years, idea to product.

It is a discipline that protects the researcher from his own enthusiasm.

When I asked whether the industry funds R&D generously enough, his answer was the honest one any researcher gives — we always want more (who doesn’t…!)

But he added the sharper point: it is not only how much you invest, it is how judiciously.

Biofouling: the only fouling that fights back

If there is one part of this conversation worth pinning to the wall of every operations room, it is Guillem’s explanation of fouling.

I have handed over desalination plants in the Middle East without ever truly understanding it.

After forty minutes with him, I finally do (to my level…).

A fouled membrane is, simply, a dirty membrane, and there are four ways it gets dirty.

Particulate fouling is the microscopic grit — colloids, bacteria, fine matter — and a good pretreatment, ultrafiltration in particular with its roughly twenty-nanometre pores, stops it at the door.

Scaling is what happens when you pull water out and the salts left behind exceed their solubility and begin to precipitate; with good design and antiscalants, and an understanding of induction time, it is well managed.

Organic fouling is the dissolved organic matter — the humic substances a river carries — that lays down a film as you permeate; you see it as a slow, logarithmic climb in energy or normalised flux, and you tame it with a sensible fouling factor in the projections. None of these three keeps a process engineer awake at night.

The fourth one does. Biofouling is biology, and biology adapts. Certain bacteria have spent far longer than humans perfecting the art of finding a solid surface and clinging to it. A reverse osmosis membrane is, from their point of view, paradise: a constant flow delivering a steady supply of food. They eat, they reproduce, they eat again, and within a week or three — depending entirely on the water — they build a gel. The gel is the problem.

It occupies the space the water needs to flow, the pressure drop between feed and concentrate climbs, and eventually the membrane is mechanically deformed and damaged.

Worse, it hides. Bacteria shelter in the feed spacers where chemicals struggle to reach, and unlike ultrafiltration — where a dose of sodium hypochlorite cleans everything, like bleach down a toilet — reverse osmosis cannot tolerate chlorine. It strips the polyamide.

So you are left fighting a living, sheltered, regenerating film with one hand tied behind your back.

A study Guillem cited, analysing around a thousand samples, found that roughly 85% of membrane fouling cases came down to biofouling. It is the dominant headache of the industry.

I’m a firm believer in the power of books. Much of my personal and professional growth has come from reading. So, if this subject resonates with you in any way, I highly recommend having Guillem’s book on your desk. It is already in our database for water books. You’ll find the link for purchase at the end of this publication.

Now ask where you can realistically intervene.

Temperature? You will not cool an ocean’s worth of feedwater; the energy cost is absurd.

Bacteria? Put ultrafiltration upstream and you stop them entering — but everything downstream is not sterile, and a single survivor is enough to start a colony. Biocides only buy a delay before the bacteria shelter and rebound.

So why is it not everywhere? Economics.

Guillem put the cost trajectory in stark terms: in the 1980s, desalinated water cost around two dollars a cubic metre, which inflation would put near thirteen dollars today. The plants now being built deliver at thirty-five to forty cents.

When water is that cheap, any added investment needs an exceptional business case to survive.

The hope is that nutrient-removal technology keeps getting cheaper until, finally, prevention beats cleaning on the spreadsheet.

Until then, the reality on the ground is what I see in the plants I commission: cleaning-in-place systems, chemical cycles, and a constant negotiation with the inevitable.

He added a point I have watched play out and never named properly:

A plant is designed for a sweet spot, with the pretreatment that keeps fouling at bay. Then the end user asks for ten percent more water.

You push the flux a little, then a little more, and the squeeze tightens until the pretreatment can no longer keep up — and by then there is no floor space left to retrofit the technology that would have helped.

A chicken-and-egg problem built into the economics of success.

Innovation in membranes: two speeds at once

When I asked Guillem how the future of water treatment looks, he gave me the most clarifying mental model of the whole conversation: innovation runs at two velocities.

The first is incremental and familiar. Elements that use a little less energy, deliver slightly better quality, or grow selective toward particular ions.

You can see this speed by reading the membranes themselves: the standard reverse osmosis element went from 370 square feet of active area in the 1990s, to 400 in the 2000s, to 440 today.

Small, steady, compounding gains — the everyday craft of the industry.

The second velocity is slow and rare and decisive. Every twenty or thirty years a genuinely disruptive innovation arrives and resets the baseline.

Thermal desalination dominated until the 1980s; then reverse osmosis took over and has held the field since. Something will eventually displace it too.

The discipline, as a researcher, is to keep harvesting the incremental gains while staying honest about the fact that you cannot schedule the revolution.

Brine valorisation: water as a chemical feedstock

Guillem’s framing surprised me. I expected hype.

Instead he reached for the technology readiness scale — where one is an idea and nine is full industrial deployment — and placed brine valorisation at TRL9. Not coming. Here.

“I have to admit that I wasn’t aware of what TRL (Technology Readiness Level) meant until a few months ago. During a conversation in our networking chat, several founders mentioned that their startups were at TRL 4, TRL 5, and so on.

So, here’s a brief summary: TRLs provide a scale to measure the maturity of a technology, ranging from TRL 1, where the concept is still an idea or basic principle, to TRL 9, where the technology has been fully proven in real-world conditions and successfully commercialized

In water tech specifically, I guess that moving from TRL 6 → 8 is often the hardest jump (real-world hydraulics, regulation, O&M complexity), but we’ll explore this further with a specific episode in the near future.

His proof is the Maven project in Indonesia. The island had a sodium chloride problem.

The OARO project aims to produce 220,000 tons of salt and 25,000 m³ of desalinated water daily.

Osmotically Assisted Reverse Osmosis (OARO explained → Standard membranes can concentrate brine up to 85,000 ppm at 80 bar, while OARO can achieve up to 250,000 ppm at 70 bar.

Salt is not a humble commodity; it is a keystone of the chemical industry, because you electrolyse it to make chlorine gas, and chlorine gas underpins the whole world of PVC and plastics.

Indonesia was importing it from New Zealand and Australia at around 130 dollars a tonne, exposed to logistics and the price shocks of a turbulent world.

So they built a brine valorisation plant. It produces salt at thirty to forty dollars a tonne — an eighty percent reduction — and, crucially, it produces fresh water at the same time.

By valorising the brine, recovery jumped from around 43% to 85%. They doubled the water and decoupled the salt from global logistics in a single move.

Read that twice.

We are beginning to see seawater not as a source of water but as a chemical feedstock with a known, fixable cost driven mostly by energy — exactly the kind of certainty a chemical business craves.

And the engineering logic is beautifully familiar. Just as desalination replaced the thermal evaporator with a membrane and a pump, brine valorisation replaces the evaporation pond — the centuries-old Mediterranean practice of flooding land with seawater and harvesting the salt a year later, ruining the soil in the process — with membranes.

It is standard desalination, reconfigured. (Guillem also left me with a piece of etymology I cannot shake — salario, salary, comes from salt, because Roman wages were once paid in it. The value was always there. We are only rediscovering it.)

Bridging that gap will force some companies to reinvent themselves and others to bring in entirely new downstream players.

But the demand is real, the example is built, and his forecast is concrete: within three to five years, the projects now on the drawing board will be executed and running.

Ultrafiltration: the right answer that is not always chosen

UF was invented around the same era as reverse osmosis, in the 1970s, but it sat quietly until the early 1990s, when a chlorine-resistant outbreak in Milwaukee — pathogens that ordinary filters and disinfection had failed to stop — made the case undeniable.

Put an ultrafiltration barrier in place, with its tight pores, and those microorganisms simply cannot pass. Adoption climbed exponentially, and as a standalone treatment UF keeps leading the way.

As a pretreatment for desalination, though, the picture is more political than technical. Well-designed ultrafiltration lowers both capex and opex and reduces the total cost of water.

Yet Guillem still sees conventional sand filters pushed in its place — sometimes because the plant builder has its own technology it knows intimately, sometimes because the land is government-owned and effectively free, which quietly erases UF’s footprint advantage from the calculation.

I have watched the same story in a brackish plant in Málaga, where the operator was convinced the plant wanted ultrafiltration, but the business model handed down to him left no room to install it.

The best technical answer and the chosen answer are not always the same, and the gap between them is usually written in the business case, not the engineering report.

What the membrane knows

If I had to compress this conversation into a single idea, it would be this: water innovation advances by recognising when an old job can be done a new way.

We replaced boiling with membranes and watched the cost of water collapse.

We are now replacing evaporation ponds with membranes and learning to read the brine not as waste but as wealth.

The hardest enemy, biofouling, will not be beaten by force but by starving it of nutrients once the economics finally allow.

And the whole enterprise only works because researchers like Guillem refuse to stay in the lab — because they treat innovation as a conversation with the people who actually run the plants.

I am already looking forward to the next chapter of this, in Marrakech, where so much of the agenda points exactly here, to fouling, and to brine.

The sea has been trying to tell us something for a long time. We are finally building the instruments to listen.

Euromed 2026

Guillem and I will be attending EuroMed in a couple of weeks.

It will be my first time there, and based on the agenda and the feedback I received from the 2025 edition, it seems like a very worthwhile event to attend (despite Porto being remembered for the famous power blackout!).

If you’re attending, feel free to drop us a message—or simply come and say hello in person. We’ll both be speaking during the event. Guillem’s sessions will undoubtedly be the most valuable ones.

As for me, I’m not particularly comfortable speaking to large audiences, but I’ll do my best to make my 15 minutes worthwhile. My goal is simple: that everyone listening walks away having learned at least one new thing.

Guillem Gilabert-Oriol joined the Water MBA in his personal capacity, and we would like to sincerely thank him for the immense value and insights he shared with our community.

1. His book on biofouling is well worth the read for anyone, expert or not, who wants to understand the enemy properly. 298 pages of pure value → Purchase Biofouling and Organic Fouling: in Reverse Osmosis Membrane Elements

2. Connect with Guillem through LinkedIn.

3. Register for Euromed 2026

Everyone says desalination problems are solved with good pre-treatment.

And everyone says most desalination issues are actually the result of poorly designed or underperforming pre-treatment.

So as you can imagine, we must talk about this :)

In previous episodes, we saw that today’s desalination business is essentially built around a membrane system, with a pre-treatment stage upstream to properly feed and protect that membrane.

Today we focus on one of the most important pretreatment stages: filtration.

In practice, there are two main approaches here:

1. gravity filtration

2. pressure filtration.

Each has its own advantages, drawbacks, and historical background, because over the years, every technology develops its own “tricks”.

Read more

Antoine runs Don’t Waste Water, has interviewed hundreds of the smartest people in this industry, and spends part of his working days on lithium, leading business development for GF Piping Systems.

I like Antoine's work because he's known for drilling deep into a topic, uncovering layers of context and insights that make the content both valuable and highly relevant.

That's exactly why I started learning about lithium through him.

Before that conversation, I genuinely didn’t understand what lithium had to do with water.

This past week, a very interesting 7th International Congress about Lithium in Latam took place in Argentina.

The key data they shared is literally those:

• Lithium demand projected to rise 40x in the next two decades

• Global output must grow 5x by 2030 to meet net-zero targets

• Energy transition requires over US$116B in lithium investment

• Latin America holds +60% of global lithium reserves

• Argentina, Bolivia and Chile jointly control ~54 million tonnes

• Chile remains the leading lithium producer in Latin America

• Chile targets 140k–180k tonnes LCE expansion by 2030

• Argentina holds second-largest global reserves (19.3 Mt)

• Argentina has 40+ lithium projects in development pipeline

• Bolivia aims for 100k+ tonnes/year production by mid-2020s

So I thought it was a great moment to catch-up with the learning journey about Lithium, and why water professionals should pay attention to this field.

You’ll understand once you read below the details.

At the end of the essay you’ll find links to other sources and references to continue your learning journey.

Start with the wall of demand

Everything in this story is driven by one fact: the world needs vastly more lithium than it currently makes, and soon.

The numbers are slippery, lithium gets counted as metal, as carbonate, as hydroxide, as chloride, and people quote whichever suits them, so it’s easy to get lost.

But the order of magnitude is solid. Global production crossed roughly a million tonnes of lithium carbonate equivalent for the first time in 2024, and most forecasts put 2030 demand somewhere between 2.5 and 3 million tonnes.

In round terms, the industry has to roughly double or triple its output inside a decade, with some scenarios pushing the multiplier higher if electric-vehicle incentives hold.

That is the engine behind every other thing in this essay.

Where lithium actually comes from

Here’s the first thing that surprised me: there are really two lithium questions, and people may confuse them.

1. The first is mining—getting lithium out of the ground. Roughly 40% comes from hard rock in Australia.

A big slice comes from the “lithium triangle”—Chile, Argentina, and Bolivia—though if we’re honest it’s mostly Chile, some Argentina, and a Bolivia that has barely started producing. The rest comes from China. Add it up and about 95% of world production sits in those few places.

2. The second question is refining—turning that raw material into the battery-grade stuff.

Once you separate those two questions, the geopolitics writes itself.

The whole game

Antoine put it in a way I keep repeating to people.

Follow that logic and the vulnerability is obvious.

If China decides its national interest is best served by keeping its lithium and its battery cells and exporting finished vehicles instead, then a carmaker in Europe or North America that didn’t secure its own supply is left with no lithium, no batteries, and therefore nothing to sell.

An entire automotive industry can be hollowed out not by losing a price war on cars, but by losing access to a metal three steps upstream.

This is why “where does my lithium come from” has stopped being a procurement question and become a strategic one.

It’s also why countries are scrambling to build domestic supply chains—and why those efforts collide with local realities.

Bolivia, sitting on enormous reserves, has leaned toward China: there was a tender that everyone could enter, and somehow only Chinese companies were selected.

Chile runs much of its resource through a national mining company holding a 51% stake.

Argentina is province by province—some welcome lithium, some forbid it outright.

Same triangle, three completely different rulebooks.

Four ways to get it out of the ground

Now to the part that finally connected lithium to our world.

Hard rock. You mine a rock called spodumene (first time I heard of…), which is only about 0.8–1% lithium, and concentrate it (using, among other things, dissolved-air flotation) into something around 6% before it goes to refining. Australia, China, Canada, and a famously contested deposit in Serbia have spodumene.

Brines. In the lithium triangle, you pump up brine and pour it into vast evaporation ponds—essentially the same technique as harvesting table salt. The sun does the work, and what’s left behind is lithium chloride, again around 6%. Cheap on capex, but slow, and it raises real problems I’ll come back to.

Clay. Newer, and what the US is pursuing around Nevada and Texas. The processing route looks a lot like the spodumene route, just with clay as the input.

Direct Lithium Extraction (DLE). This is one interesting. DLE uses water-treatment technology—membranes, ion exchange, adsorption and desorption—to pull lithium out of brines too dilute for the old methods. We’re talking 200–400 parts per million, sometimes as low as 60.

When waste becomes the resource

The DLE example that stuck with me is oil fields. When you pump up a litre of oil, you bring up something like eight litres of water with it.

For a century that water was pure waste—a disposal cost. It turns out some of it carries 40–60 ppm of lithium. If you can extract that, the waste becomes a by-product becomes a revenue stream.

That is the exact same arc we keep talking about in water: the thing you used to pay to throw away turns out to be valuable if you have the technology to unlock it.

Technologies that were always too expensive for water—overkill if all you’re doing is making drinking water—suddenly become competitive when the prize is one specific, high-value element of the periodic table.

And it’s not a one-shot opportunity. It seems baattery-grade lithium has to be 99.99% pure.

Getting from 6% to five-nines is a long road of chemical and water treatments on the brine side, or roasting-and-leaching followed by more chemistry and water treatment on the rock side.

Every step is a place where membranes, ion exchangers, and adsorption come into play. For a water-technology company, exciting opportunities.

Why it takes a decade and a billion dollars

If demand is screaming and the prize is huge, why isn’t supply catching up faster? Because mines are slow and brutally capital-hungry.

A hard-rock mine takes roughly 5–10 years to open.

An evaporation-pond operation takes 10–15.

DLE at full commercial scale is so new that nobody honestly knows yet—the projects are ramping, not proven.

And every exploration drill can cost around a million dollars just to find out whether what’s underground is even worth chasing.

So how do you fund a decade of pure cost? Two routes.

1. Some companies go public absurdly early, raising money on the stock market while still in exploration.

2. Others sign offtake agreements: a carmaker buys the future lithium before a single tonne exists. General Motors did exactly this with Lithium Americas’ Thacker Pass project in Nevada—committing well over a billion dollars across stages for a 38% stake and access to production, even as the project is still being built. (In a sign of how strategic this has become, the US government itself took a roughly 10% position in the company in late 2025.) Stellantis has chased European lithium the same way. The one big holdout is Tesla, which believes its market position makes it immune to a shortage.

The driver underneath all of it: gigafactories. There are dozens planned across Europe and North America, and the rough rule is one gigafactory needs about one lithium refinery to feed it. Build the factories and you’ve made an enormous, standing bet that the lithium will show up.

Hovering over the economics is a price that has been on a rollercoaster.

Pre-COVID, a tonne of lithium ran around $4,000–5,000. A year after COVID it spiked toward $80,000–100,000.

It has since crashed back to roughly the $10,000–15,000 range—still well above where it began, but a long way down from the bubble, and enough to push marginal projects into delay or bankruptcy.

Several Canadian projects, advanced but undercapitalised, simply died during COVID, which is part of why the rebound in demand hit such a thin supply base.

The Bolivia problem, and the skull on the wall

Two things complicate the romantic picture of “just evaporate brine in the sun.”

1. First, chemistry. Bolivia has enormous lithium but a lithium-to-magnesium ratio roughly 30 times worse than Chile’s.

When you try to precipitate the magnesium out, you drag lithium out with it, so process efficiency collapses—from the 40–45% you might see in Chile or Argentina down to something far lower.

Abundant sun and resource can offset that, but it’s a real handicap.

2. Second, water. Brine isn’t drinking water, but it is water, and the salars sit in some of the most arid places on Earth.

Draw too much from the bottom of the system and the whole water table can fall. Antoine described seeing, in Argentina, walls painted with the word “Litio” beside a skull—and, across the road, communities cheering the same lithium for the jobs it brings to places that never had any.

Two faces of one coin. That tension, more than any spreadsheet, may decide where the industry can actually operate.

Where this is heading

Lithium was and probably is one of the most exciting frontiers in water, precisely because almost nobody in water is calling it a water story yet.

The demand wall is real.

The geopolitical squeeze is real.

And the technical answer—how you economically extract a few hundred ppm of a metal from brine, or recover it from oil-field wastewater, or polish it to XXX purity—may be, fundamentally, a water-treatment problem.

I went in knowing nothing. I came out convinced this is a corridor of opportunity that water professionals are walking past without recognising the door.

Why a busy engineer makes a podcast

I couldn’t end without the part of the conversation that wasn’t about lithium at all, because it’s the part that explains why people like Antoine exist to teach the rest of us.

He started Don’t Waste Water during COVID, almost by necessity. He’d just moved into a business-development role for water and wastewater, right as lockdown made it impossible to meet anyone.

So he turned the constraint into the method: reach out to the people he knew, put the conversations in public, and let that visibility pull in the people he didn’t yet know.

(It wasn’t even his first podcast—an earlier one walked through 55 sales books after he was thrown, untrained, into selling a treatment plant for Suez and survived on Sales for Dummies and sheer nerve.)

What I loved most was his honesty about why he keeps going.

The catchphrase is that listening to the show gives you a “water MBA” but, he told me, the water MBA he’s really earning is his own.

An hour a week with a superior mind, 250 weeks in a row, knowledge poured straight into his head.

He called it egoistic, self-centred, and meant it as a compliment to the format.

The fact that thousands of other people benefit too is, in his telling, a happy side effect.

That landed, because it’s exactly how I think about this work. People ask whether I’m wasting or spending time and money on it.

I use a different word: investing. Even in the scenario where the subscriber count stays at zero, the return—in learning, in conversations like this one, in the simple joy of staying curious—is already positive.

You do it because you like it, or you don’t do it at all.

Thanks everyone for reading, sharing and engaging.

Here a few links to continue this topic:

• Lithium International Congress LATAM

• Don’t Waste Water Podcast Channel

• Antoine’s Walter Channel

• Interesting video from Antoine:

That’s why we created the Water Jobs section, why we have the networking chat, and why we encourage members of the Water MBA community to connect with one another, exchange ideas, and explore new opportunities.

But a large part of it still follows the typical CV and interview process, as we all know.

There are usually two scenarios.

1. First, you are the one attending interviews for different positions.

2. Second, you are the one conducting interviews to bring people into your company or department.

Something interesting happened over the last months. Since the beginning of the Middle East conflict, literally on the exact same day it started, I thought: this could become significant.

My corporate work is mainly based in the Middle East, so I said to myself: I’m going to test the waters a bit because I honestly don’t know what is going to happen here.

Purely from an intelligence and market-awareness perspective, I became involved in several interview processes, which I want to talk about below.

At the same time, the purpose of this article also comes from the fact that over the last years I have been hiring people for the department or projects and conducting interviews myself.

Honestly, this combination — this intersection between seeing what different companies are demanding, understanding what you personally look for when hiring, and also tracking the type of offers and profiles constantly appearing in the market or being discussed by people around you — has been extremely interesting.

Read more

I nodded politely. Another engineer in love with his niche.

Year after year, that pipe has shown up in more of my projects, more bids, and more conversations across the global water industry.

That’s why I wanted to bring a super interesting case study around those pipes, with the presence of Dolores Herran from Molecor.

I simply love the business model behind it.

That’s the part I think most water professionals, and especially the MBA-minded ones reading this, completely miss.

So let me front-load the value before I tell you the company story that prompted all this.

What “oriented” actually means

Take two pipes, both labeled DN200. One is standard PVC. The other is oriented PVC — PVC-O.

Drop either into an irrigation network or a pumping main and, on paper, they look interchangeable.

❗They are not.

The molecular orientation process realigns the polymer chains, dramatically improving the mechanical properties of the pipe.

Same chemistry — it’s still PVC, with all the corrosion resistance and chemistry advantages of plastic — but now you can achieve the required pressure rating with a thinner wall.

Think of an aircraft: same job, lighter material, but engineered to be stronger where it counts.

Thinner walls mean three things that compound:

• A larger internal diameter for the same external diameter. More free section.

• Higher flow capacity. Flow equals velocity times section, so more section means more water moves.

• Lower head loss thanks to a smoother, less rugose internal surface — which directly cuts pumping energy.

A pipe that’s slightly more expensive to buy but saves pumping energy for 20, 30, even 50 years isn’t a cost. It’s a return.

As Dolores Herrán of Molecor put it to me, with the weariness of someone who fights this battle daily:

“CAPEX, CAPEX, CAPEX — and never OPEX.”

She told me about a large-diameter case study where, over 20 years, the energy savings delivered to a water utility roughly equaled the entire cost of the project.

The installer might not care. But the operator absolutely should — and increasingly does, as everyone bets that energy prices only go up.

The real innovation wasn’t the pipe, it was the air

PVC-O wasn’t invented by Molecor. The molecular orientation of pipe was discovered almost by accident in the UK in the late 1970s.

The original method was clumsy and energy-hungry: heat an initial tube with water, pressurize it with water, expand it, then cool it with water inside a mold. It worked — it was running in Britain by the 1980s — but it was inefficient.

That single substitution became the revolution. Manufacturing the pipe with air rather than water is the core of Molecor’s technology, and it’s why a company founded in 2006 by two friends who met on an Executive MBA at IE Business School could go on to validate a prototype, build a business, and stretch their product range from 90 mm all the way up to currently 1,200 mm in diameter.

It’s also, characteristically, an innovation built entirely from scratch. There was no roadmap. Molecor even had to help write the standards and develop the PVC-O fittings themselves, because the market simply didn’t have them yet.

Why you don’t ship air across an ocean

When I was running bids for water pipeline projects — estimating quantities, requesting quotes, comparing steel against polyethylene, polypropylene, GRP — there was always one truth about pipe procurement: you’re shipping mostly empty volume.

A pipe is air wrapped in a thin wall. Put it in a container and send it from a Spanish factory to a project in Paraguay, and you’re paying to transport air across the planet.

This is exactly why the local player always seemed to win on price. They adjust to the local market equilibrium, and the importer simply can’t compete once freight is loaded in.

Molecor’s answer to this is elegant: don’t always ship the pipe, ship the technology. Sell the machine that makes the pipe, and let it be built locally.

That’s the dual model. They wear two hats at once: they manufacture the technology and they operate it themselves.

As Dolores explained, being the operator of their own technology is precisely what makes them credible when selling machines to a third party — “I’m the one who builds the machines for myself,” which gives them enormous flexibility.

Win a 300-kilometer project of DN1200 in the Philippines? Ship a production line there.

But the decision of whether to ship pipe or plant a factory is purely a question of volume:

• Low volume, opportunistic: ship the pipe, or partner with a local player on a single big project.

• Proven volume: stop “transporting air” and establish a local plant (as they did in South Africa, and are now doing in Turkey).

This is the flywheel. Enter a market, prove the product on a trial project, build volume, then localize. Each turn of the wheel funds the next. Dolores said it best when I asked her how Molecor exports:

“There isn’t one way to export. Each market is different. I carry the same product, the advantages are the same — but I have to tell them differently in one market than in another.”

Where this pipe actually wins

A clarification worth making, because PVC-O is not a pipe for everything. The sweet spot is pressurized water transport, roughly 12.5 to 25 bar, in buried trenches, within that 90 mm–1,200 mm range.

Applications? Many. Check out some examples below.

And here’s the strategic detail that took me years in the industry to internalize: by the time a pipe spec lands on your desk in writing, it’s too late to change anything.

The Molecor story

Two of the founders, Ignacio Muñoz and José Manuel Romero, met on an Executive MBA at IE in the early 2000s. The idea for Molecor grew out of one of those MBA projects we’ve all had to do. The company was incorporated in 2006 with a single bet: build a technology to manufacture oriented PVC pipe, using air.

Dolores joined in 2007. A structural engineer by training, she’d been calculating building structures when a professor connected her to Ignacio.

She jumped to a six-person startup selling a technology that didn’t even exist yet and, by sheer luck, did so right before the Spanish construction crisis gutted her old sector. They validated the technology that same year.

What followed reads like the flywheel in motion. AENOR product certification in 2009. Spain’s infrastructure market collapsing around 2010–2012, which forced them international — their very first machinery sale went to Australia (”we couldn’t have gone further,” she laughs).

Then a steady, market-by-market grind: a first joint venture in South Africa in 2016 (chosen, pragmatically, because the country already had a standard to anchor to); five years spent developing the standard in India from zero; an acquisition in Malaysia in 2022 to crack Southeast Asia.

Today Molecor has commercial presence in more than 30 countries and owns plants in South Africa, Malaysia, Paraguay and, as we speak, is opening its fifth in Turkey, with inauguration slated for this summer.

The plan from here? Keep widening markets, but shift the emphasis from selling the technology to establishing themselves — owning a piece of the growth rather than just banking a machine sale.

North America, Latin America, and Southeast Asia…, alongside hard-won validation work in the Middle East — trial projects in Oman, certification grinding through Saudi Arabia — where oriented PVC has essentially no presence yet.

When I asked Dolores about going public, she laughed it off:

“Not yet. We’ll see. We still have a long way to go. What motivates me most is that we’re still at the bottom of the growth curve.”

If Molecor were listed, I’ll admit, I’d be tempted. For now, I’ll settle for telling you the story.

If you want to dig into a proper CAPEX vs OPEX lifecycle analysis for water infrastructure, let me know, I’ve been meaning to put together a session on it. And if you’d like an introduction to Dolores or the Molecor team, reach out; the water industry runs on the conversations that happen behind the curtain.

What is especially interesting is that many of these people are not “water natives, they come from firms, consultancies, associations, and other sectors that traditionally worked in different fields but are now stepping into water. They see opportunities in the sector, although many are not fully sure why.

Water is intertemporal. It means that decisions we made, or failed to make, years ago, such as renewing infrastructure or improving water resilience, are inevitably showing their consequences today.

Curiously, many water professionals themselves are not fully aware of the global movement happening around water. They are focused on their day-to-day workload, delivering projects, and handling operations.

The water business is moving fast, and many people are simply unaware of how much the sector is changing.

I usually explain a few key points to those who ask me why water is trending, and I would like to share them with you.

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Today I want to keep talking about water reuse and brine valorisation, but not in the technical way.

Many of you already know our guest, Christos Charisiadis from Brine Consulting.

I had the chance to meet him almost two years ago, and he has become one of those references you keep coming back to, one of those people who chose a niche so specific that, over time, the niche became a field, and the field became a movement.

The first time I heard the words brine mining, it was September 2023, in Seville, at the IDA Congress. And honestly? It sounded like Chinese to me.

Getting what out of the brine? I had spent years designing and handing over desalination plants. My only worry about the brine was whether it could be discharged without air entrainment issues, and whether we could execute the outfall on time. That was it. That was the whole brine conversation.

I thought there was no other choice. The brine was waste. The brine went back to the sea. End of story.

But it seems there is another choice. And like any big shift, it takes time.

A brief 4 minutes segment of the above conversation was uploaded in our Youtube Channel, in case some of you find more convenient this platform to get some insights:

The moment

The thing that broke my frame was a conversation with a friend about Taweelah Desalination Plant 900 MLD, in which I was involved as Engineering Coordinator.

Taweelah produces around one million cubic metres of fresh water per day. It also produces about 1.5 million cubic metres per day of brine that goes straight back to the Gulf.

And nobody on the team thinks of it that way, because we’ve all been trained to think of brine as the byproduct, not as the thing.

That’s when the brine valorisation conversations started to make sense to me. As something obvious that we’d been ignoring because we were too busy delivering the project on time.

So why does it take so long?

This is the question I keep coming back to. Innovation and technology deployment take time. Fine. But why does it take so long, and what can we actually do to adopt this faster?

Christos gave me a frame, he said engineers tend to think in CAPEX and OPEX. Two axes.

And risk doesn’t scale linearly with project size, it scales geometrically. Double the plant, you don’t double the risk. You multiply it by something much uglier.

That’s the first answer to why it takes so long. The bigger the operation, the bigger the prize, and the bigger the fear.

And right now we’re still at the stage where the technology providers are telling clients “trust us, this will work for 20 years” and the client is sitting on the other side of the table thinking I have never heard of any of this and you want me to bet a billion dollars on it.

Which leads to the line that made me laugh and wince at the same time:

“ZLD doesn’t make commercial sense unless you have a knife on your throat.”

Zero Liquid Discharge, the dream of getting everything out of the brine, leaving only dry salts, only happens when a regulator is forcing you to do it, or when your operation literally cannot continue without it.

Otherwise, the economics don’t close.

The crystalliser alone consumes 60 to 90 kWh per cubic metre. The capex for the alloys is brutal. In a full brine ZLD scheme, the thermal crystallisation step can eat 60% of the total project cost.

So the realistic sweet spot, for most of us, isn’t ZLD. It’s MLD — Minimum Liquid Discharge.

Concentrate more, recover more water, leave a smaller, more interesting brine behind.

Does this mean the ZLD market is going down? Not at all, quite the opposite, especially in industrial applications. However, in desalination schemes, MLD will probably be the next step.

You can also see ZLD approaches, for example, in King Salman Park. And of course, the China and India ZLD markets, as we mentioned in our previous episode, continue expanding as well.

Actually, this week the project was awarded in Global Water Summit as Reuse Project of the Year.

Which minerals actually make business sense?

Here is where I had to update my mental model. I used to assume that if you were going to recover anything from seawater brine, it would be salt. Sodium chloride. The obvious one.

Sodium chloride is about 30% of the dissolved load in seawater RO brine, which means recovering it produces enormous volumes of a product with very low commercial value.

Locations such as Indonesia and Canary Island may have strong business cases for sodium chloride. As they import this “basic” material, but at a very high cost. And you know what? For instance, the Canary Islands rely on desalination for a large percentage of their water supply, meaning they are discharging sodium chloride into their coastlines. They could potentially recover it, probably within a reasonable business case.

Other interesting molecules, business-case-wise, are magnesium and bromine.

Magnesium especially is interesting, because the geopolitics of magnesium supply have become uncomfortable for a lot of countries and the price reflects that.

Magnesium primary purpose is acting as an essential alloying agent that gives aluminum structural strength and corrosion resistance, alongside being die-cast directly into vital automotive components like steering columns, gearbox casings, and seat frames. Because pure magnesium oxidizes rapidly, it cannot be stockpiled long-term; the entire global supply chain operates on a fragile, just-in-time delivery model that relies on China for up to 90% of its primary production.

This extreme geographic concentration turned 2022 into a disastrous year for industrial procurement. Following sudden energy-rationing mandates in Chinese smelting hubs, global supply vanished overnight, forcing market prices to skyrocket from a historical baseline of $2,000 per metric ton to unprecedented peaks of over $10,000. Because magnesium has no viable metallurgical substitute, this supply shock triggered a massive industrial panic, forcing aluminum producers to halt shipments and threatening a total shutdown of global automotive assembly lines. The crisis ultimately served as a severe geopolitical wake-up call, prompting Western nations to officially designate magnesium as a critical strategic mineral and aggressively fund localized recycling and alternative supply chains.

Bromine serves as a highly sensitive geopolitical choke point due to its extreme supply consolidation, with Israel’s Dead Sea operations and the United States' Arkansas brine fields controlling over 60% of global output, leaving major industrial hubs acutely vulnerable to regional instability.

Bromium acts as a quiet chemical gatekeeper for three massive global industries: the electrical and electronics sector—where it protects printed circuit boards and powers memory chip manufacturing—the energy sector, and the construction industry.

And then there’s the other category: the strategic minerals.

Lithium is the obvious one, the EV transition runs on it, and most of the world’s lithium currently comes from a handful of salars in Chile, Argentina and Bolivia.

Direct Lithium Extraction (DLE) from brine is still maturing, but the pressure to develop it is enormous, because every country now wants its critical minerals produced somewhere it can actually defend.

The El Paso example Christos mentioned.. The biggest inland desalination plant in the world, brackish water, huge volumes.

They’re concentrating further, precipitating calcium sulphates, splitting the rest into acid and base via bipolar membranes, and they already have commercial buyers for all three products.

The geography worked: enough volume, close enough to customers. Brine valorisation is, in the end, a logistics problem dressed up as a chemistry problem.

The regulatory piece

This is the part of the conversation I wish we’d spent more time on.

Right now, in most jurisdictions, the brine discharge permit is the binding constraint. If the regulator lets you discharge, you discharge.

If the regulator tightens, either through a discharge fee, a salinity cap, or a flat ban in sensitive ecosystems, then suddenly the math on MLD and brine valorisation changes overnight.

The “knife on the throat” Christos talked about is, almost always, a regulatory knife.

Inland desalination in the US is already pushing the issue because there’s nowhere to discharge. And the geopolitical conversation about critical raw materials means governments are starting to look at brine not as a waste stream but as a domestic mineral resource sitting in plain sight.

The regulator may be the one who decides whether your brilliant valorisation scheme gets built or stays on a PowerPoint slide forever.

And then the client enters panic mode

This was the part I laughed at the most, because it’s so true.

“If you put these things in front of a client that has zero idea about water, they get immediately into panic mode.”

Anyone who has presented a non-standard water solution to a non-water client knows this scene by heart. You’re explaining the process…showing the recovery numbers, through the mass balance.

And you can see the moment, usually around the third slide, when the client’s eyes glaze over and they stop hearing the technical argument and start hearing risk. Just risk. Pure undifferentiated risk.

And if the honest answer is “not exactly, but —” the meeting is effectively over. They want someone else to do it first.

They want a BOO or a BOT or a PPP where someone else is holding the risk. They want references they can call. They don’t want to be the case study.

This is the actual reason adoption is slow. It’s that the people writing the cheques cannot tolerate being the first one to find out what doesn’t work.

And so we sit, collectively, waiting for someone braver, or someone with a regulator’s knife at their throat, to go first.

So what do we do about it?

We build the references. We talk about the projects that do work, even the small ones, even the partial ones — calcium precipitation here, magnesium recovery there, a brackish-water MLD scheme somewhere else.

Every small commercial success makes the next client a little less panicked. Mega-projects matter not because they’ll be perfect but because they’ll generate the operating data the industry has been starved of.

We also have to do something engineers find genuinely hard, which is talk like humans.

Christos said it better than I will: we need to build cross-industry skills.

And finally — and this is the part I want to say to anyone early in their career — patience and presence.

This space rewards people who stick around.

The conferences, the working groups, the technical committees, the awkward LinkedIn posts. It all compounds.

The reason Christos is the person I called for this conversation is that he has been in the same niche for ten years, refusing to leave, while the rest of the world slowly caught up to where he already was.

That’s the job. Help the next client be a little less afraid.

From top to bottom:

1. Client

2. Consultant

3. Developer

4. Contractor

I’ve been reflecting these days about it.

• Which scale of the ladder are you on?

• Which position is best for water professionals?

• What are the differences between them?

• If I had to advise someone starting their career journey, what would I tell them?

• Which profiles are missing in the water MBA community?

• Where can you earn more money?

• What are the pros and cons of each path?

Where you “pick” to work depends heavily on whether you prefer high-level strategy, technical design, or the “boots-on-the-ground” reality of building things.

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Today, I encourage you to take this episode COMPLETELY, it gets better as it develops. Whenever you can, find 45 minutes in the coming days and watch the full video.

Pay close attention to our guest. He is one of the most inspiring and insightful people I’ve met in the last three years, which is exactly why I invited him to join the conversation.

For years, when I told friends China was probably handling water better than most of Europe, they looked at me like I’d lost it. The image is sticky for them: smog, polluted rivers, opaque industry. It takes a while to update.

China sells water rights. They’ve been doing it for a decade.

This was the moment that genuinely surprised me, and David told me it surprised Alejandro Sturniolo too when they discussed it last year.

About ten years ago, China set up what is effectively a water rights exchange market, a public, government-owned marketplace where the right to use water is allocated by basin, tied to the GDP a province or city has committed to producing.

If your industrial activity needs more water than your allocation, you don’t just pump more. You buy the right from a neighboring province in the same basin.

It’s not identical to the “water positive” or water credit frameworks emerging globally, but the underlying philosophy is the same: water is a finite resource with a price, and you cannot consume it faster than the system says you can.

China implemented this at national scale a decade before most of the world started seriously talking about it.

The reason is brutally simple.

A thousand years ago they were already digging tunnels to move water around. Today they’re pricing it into the economy.

Groundwater is, for industry, essentially banned.

In most countries, regulating groundwater is a political nightmare. In China, for industrial use, it’s mostly settled: forbidden.

Agriculture can still apply for permits, but with strict caps.

The default assumption in industrial planning is that you will not be touching the aquifer.

Try imagining that conversation in your own country.

The world’s largest Zero Liquid Discharge market is in China

This was the part I most wanted to flag for our community. China is the world’s largest manufacturer of petrochemicals, steel, cement, and most of the heavy industries that produce nasty wastewater.

Combine that with the water rights system above and the groundwater ban, and you get a regulatory environment where industrial sites have one realistic option: Minimum Liquid Discharge (MLD) or Zero Liquid Discharge (ZLD).

David estimates that China holds 60–70% of the global market for the core ZLD technologies, particularly evaporation and crystallization.

If you’re buying a ZLD system anywhere in the world right now, the heart of it was very likely engineered or built in China.

There’s a fascinating bit of behavioral history here.

A decade ago, plants would build a ZLD system to pass inspection, then quietly bypass it because operating costs were too high.

The fix wasn’t a better fine, it was making the owner of the company personally liable, including jail time.

As David put it: “the market is much worse than the money.”

Once that became real, the operations market caught up to the construction market, and the technology kept improving because it had to.

That’s a regulatory design lesson worth sitting with.

Landfills are essentially gone. Power plants now compete for garbage.

Around a decade ago, China subsidized power generation from waste burning, not solar, not wind, but garbage-to-energy specifically. The goal was to make burying waste economically irrational.

It worked so well that the subsidy was removed two or three years ago because it was no longer needed.

Today, power plants in different cities compete on price to acquire garbage from one another, because without garbage they can’t generate power and they can’t earn margin. Landfills have been almost entirely closed.

The leachate technology market that used to exist around landfills has shifted to dewatering leachate from pre-incineration processes.

David was honest about the gap: China is still behind countries like Germany or Finland on garbage classification at the household level. That’s a real weakness. But the disposal end of the system has been re-engineered in a way most Western cities are nowhere near.

The honest weakness: hyper-competitiveness eating itself

I asked David directly what China is not doing well, because lately I struggle to find weaknesses, and I don’t trust that instinct.

His answer was surprisingly self-critical, and I think important.

The problem is mentality. When a technology matures in Europe, maybe 5–10 companies manufacture it.

When it matures in China, 10,000 do. And then those 10,000 don’t compete on quality or R&D; they compete on price, racing each other to the floor.

David called it “out of logic competitive.” It hurts foreign competitors, yes, but it also hurts Chinese entrepreneurs like him who want to invest margin into next-generation R&D.

You cannot fund the future on zero-margin commodity pricing.

The government is aware and has tried to push back with policy, but he doesn’t think those measures are working yet.

This is the most honest “constructive critique” of the Chinese water industry I’ve heard from someone inside it, and it tracks with what I see at trade shows.

Why he’s betting on tubular ceramic membranes

David’s company, Conceptech, makes tubular ceramic membranes, and the reasoning behind the bet says a lot about where he thinks the industry is heading.

His starting concern is one most of the industry doesn’t like to talk about: the membranes we currently rely on — PES, PVDF, PP, polyamide — have a manufacturing process that is not environmentally friendly, requires heavy chemical use, generates significant wastewater, and produces modules that at end-of-life become waste themselves.

We are, in his words, using non-sustainable technology to purify water and calling it sustainability.

Ceramic membranes are made from earth and high-temperature firing. After their service life, you can return them to the oven and remake them.

The catch right now is cost — ceramic is roughly 15–20 times more expensive per square meter than PVDF — which limits adoption to applications where stability matters more than price (pharmaceuticals, semiconductors, certain industrial reuse).

Tubular vs. flat-sheet matters too.

1. Flat-sheet ceramic is cheaper to manufacture and works submerged like an MBR, but every maintenance event means draining the tank.

2. Tubular runs inside-out like a reverse osmosis skid — higher membrane cost per square meter, but lower CAPEX on infrastructure and dramatically lower OPEX over time. For long lifecycle thinking, tubular wins.

The challenge is making good tubular ceramic at low cost, which is where Conseptec’s manufacturing innovation (the one that won them a 2024 Sustainability Award in Saudi Arabia as well as below in latest WEX Global 2026 in which I was part of the judge) sits: a precision-controlled heating process that drops energy consumption — the dominant cost driver, since raw material is under 20% of total cost — significantly.

And here’s the wedge that’s opening the market for them faster than expected: PFAS regulation in the EU and UK.

Once you’re inside a PFAS-free requirement, ceramic stops looking expensive. It starts looking inevitable.

Continue the discussion

I want to leave them as open questions rather than tidy conclusions:

1. Lifecycle cost analysis is still a rare skill.

David and I agreed that maybe 1–2% of professionals genuinely run a real CAPEX-plus-OPEX-plus-end-of-life analysis.

Most people pick the cheaper sticker price and call it a day. Until that changes, sustainable technologies will keep losing tenders they should win.

2. Regulatory design beats technology cheerleading.

China didn’t get to a functioning ZLD market by inventing better evaporators.

It got there by making non-compliance personally costly to executives, banning the easy alternative (groundwater), and pricing water at the basin level. Technology followed.

3. The “today’s tools are the final answer” trap is real.

David said something I keep turning over: he doesn’t believe the membranes we use now will still be in use in 300 years.

The honest entrepreneurial question isn’t “what’s the best product on the shelf?” it’s “what does the shelf look like in fifty years, and am I building toward it or away from it?”

4. And finally: keep updating your map of China.

The country David described is not the country most Western water professionals describe at conferences.

If your mental model is more than a few years old, it’s wrong. Go visit. Talk to people like David. Be willing to be surprised.

Thanks again to David Bailey for his time and his honesty, including the parts that weren’t flattering. That’s the conversation worth having.

So you want a good membrane. Inside a reliable pressure vessel. And nicely supported by a friendly steel frame.

(I know later come the pumps, the pipe interconnections, valves, energy recovery devices — it all counts...)

But today we talk about:

1. The strategy for how to deploy the heart into our project.

2. Who are the surgeons in the market?

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The pipes are underground. The treatment plants are tucked away.

The operators work in silence, and the public only notices when something goes wrong.

We tend to take water for granted. Turn on the tap, water comes out.

Flush the toilet, it disappears.

Marco put it simply: the traditional approach is to hire a consultancy, give them your data, wait weeks, get a report, and then... try to follow up.

The problem is that a report is a snapshot. Reality is a moving picture. By the time the recommendations are implemented, the conditions may have already changed.

This is where real-time analytics changes everything. Not because it replaces human judgement — it doesn’t, I hope… — but because it arms the operator with the right information at the right moment.

It turns a reactive industry into a proactive one.

The leakage paradox: we know the problem, but not where it is

One of the clearest examples Marco gave was around non-revenue water.

Most utilities know they are losing water. The question is where.

We already reviewed the main common technologies that main utilities use in their daily operations, in some previous episode.

And that gap, between knowing a problem exists and knowing where to act, is exactly where digital tools can make a transformative difference.

InfoTiles connects SCADA readings with network GIS data to model risk across every pipe in a district metered area.

The resul is “these specific pipes, in this specific area, near the river, carry a substantially higher risk than their neighbours, start there.”

That is the difference between sending a team out with a general brief and sending them with a precise target.

And in an industry where budgets are highly stretched and operational time is precious, precision is key.

The same logic applies underground, in the sewer

What surprised me most was seeing the same framework applied to wastewater.

The challenge there is inflow and infiltration, unwanted water entering the sewer system through cracks, faulty joints, or groundwater intrusion (countries such as UK, Italy, Poland, Belgium, have real issues in this aspect).

You might know the problem exists at the treatment plant level, but when the network connected to that plant covers 1,000 or even 2,000 kilometres of pipe, “somewhere in the network” is not actionable.

What InfoTiles does is map every pumping station to the pipes it serves, run a risk model, and express the result in terms of cost and even CO2 footprint.

Suddenly you are looking at a real operational and financial decision.

In their demo, four stations out of 150 accounted for 50% of the total unnecessary cost.

That kind of prioritisation is what turns a problem into a plan.

The silver tsunami and what we are about to lose

Marco used a phrase I had heard before but that hit differently in this context: the silver tsunami.

The wave of experienced operators approaching retirement, taking with them decades of tacit knowledge about how their specific networks behave, knowledge that was never written down, never digitised, never transferred.

This is one of the most underappreciated crises in the water sector, but actually applies to all societies with certain demographic population status.

And it is not just a human resources problem. It is a decision quality problem.

When the person who knew intuitively that “that pump always acts up after heavy rain in October” retires, and that knowledge is not documented anywhere, the next operator starts from zero.

The goal of a well-designed digital platform is to capture that institutional knowledge — in the data, in the models, in the alerts — so that a newly qualified engineer and a 30-year veteran arrive at the same decision when facing the same problem.

The real barriers are not technical

I asked Marco directly: what is stopping this from scaling faster?

His answer was honest and revealing. In the early days, it was access to data, utilities were reluctant to share because of uncertainty about data quality, or simply because they had never been asked to trust an external platform with their operational information.

But the deeper barrier is cultural. The water sector is, by nature, risk-averse. And the consequences of getting it wrong can be serious. But that same conservatism can slow the adoption of tools that would dramatically reduce operational risk in the long run.

There is also the feedback loop problem. In digital advertising, you run a campaign and see results in hours.

In water infrastructure, you invest in pipe rehabilitation and measure the impact over months or years.

That long feedback loop makes it harder to build the internal business case even when the data is sitting right there, ready to be read.

Questions worth asking in your own organisation, for operators and utility managers:

1. Do we know not just how much water we are losing, but where, and in which part of our network is the risk highest right now?

2. When an experienced operator retires this year, what decision-making knowledge leaves with them and where is it documented?

3. Are our SCADA and GIS systems talking to each other, or are we still doing that join manually in a spreadsheet?

4. If we fixed the top five most critical zones in our network today, what would be the year-on-year cost saving, and do we even know what those zones are?

5. Is our reluctance to share operational data with a digital platform about genuine risk or is it inertia?

A note on AI, and keeping it honest

We also talked about the role of AI in all of this.

The temptation in any industry is to layer generative AI on top of everything and call it innovation.

But in water, where the data is complex, the formats are non-standard, and trust takes years to build, the smarter question is: where does AI genuinely add value and where does it just add noise?

I’m preparing a specific workshop and course with Sandro Hanseen about AI in water. If there is any topic you’d prefer us to focus on, let us know in this poll so we can prioritize what the audience needs most.

Imagine an operator asking, in plain language, “what should I do today?” and receiving a prioritised, evidence-based answer drawn from real-time sensor data, network models, and historical performance.

That future is closer than most utilities realise.

Wait, wait… the future has already caught up with us! Do you realize how fast everything is evolving, and how important it is to stay updated in our industry?

A Large Language Model (LLM) on top of PipeFusion, reading the outputs of our graph-based network (GNN) analysis and converting them into plain-language decisions.

Water and wastewater networks are complex. A single utility may manage tens of thousands of pipe segments, valves, sensors, and connections across ageing infrastructure with highly variable data quality. We have spent years building tools grounded in graph theory to model flow, detect anomalies, and quantify risk across every asset in a network.

The persistent challenge has been the last mile. Our models can identify that a specific asset carries elevated failure probability. What they could not easily do, until now, is tell an operator what to do about it, in the context of budget constraints, operational history, and comparable interventions.

By connecting the LLM to our risk and graph outputs, the system can reason across thousands of assets simultaneously. It surfaces the interventions most likely to reduce risk per unit of spend, explained in language a decision-maker can act on directly.

This work is part of a formal R&D programme supported by Norges forskningsråd (the Research Council of Norway). That backing matters. The work is structured, independently held to standard, and built to go well beyond proof-of-concept.

We are in early conversations with utilities who want to be part of this journey. Security, compliance, and data governance are not afterthoughts, they are part of the process from day one. Critical infrastructure demands that standard, and we hold ourselves to it.

This was a controlled test, not a production deployment. But the results were clear enough to give us genuine confidence that we are building something useful for the people responsible for delivering water to our homes and taking it away again.

What I took away

There is a phrase Marco used early in our conversation: water first, software second. It sounds simple, but it is actually a reframing of what digital transformation in this sector should mean.

The best digital tools in this space are the ones that get out of the way and let skilled operators do their jobs better.

They do not replace expertise, they amplify it. They do not add complexity, they reduce it.

And they do not promise miracles, they make the next right decision a little clearer, a little faster, every single day. Like The Water MBA :)

That, to me, is what transformative digitalisation actually looks like in the water sector. An evolution, quiet, rigorous, and deeply necessary!

This workshop pairs perfectly well with episode with Harry Polman last Sunday, so you can have the a full picture.

If the intake pipelines aren’t maintained, the plant cannot run at full capacity, as we already mentioned.

This leads to penalties, unhappy clients, and, most importantly, a lack of water for the people and industries that need it.

Pigging is a tool that prevents these failures, yet it is often overlooked during the design phase! It looks simple, but it is quite tricky in certain aspects.

So here I try to share the main lessons to consider in your projects when approaching pigging systems.

The reality of marine growth

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Biofouling, maybe the most addressed word in desalination (after energy consumption).

I wanted to attack this topic from different angles, one of them is today with Harry Polman from H2O Biofouling Solutions.

Harry has spent over 30 years studying how marine life interacts with industrial infrastructure.

We talk a lot about membranes, but we rarely focus on the very beginning of the process.

Harry’s perspective is refreshing because he looks at the biology of the ocean to solve engineering problems.

We are working with nature, not just against it.

The hidden biology of our pipes

Seawater intakes are perfect habitats for marine life. Organisms like mussels, oysters, and barnacles enter our systems as tiny larvae. Once they find a surface with a good flow of water, they attach and grow rapidly.

I am aware of a real-world case where seawater did not reach the intake pump station at the expected flow rate.

Why?

Because inside the intake pipe, instead of having the intended internal diameter (let’s say 1600 mm), the effective diameter was much smaller due to marine growth.

As a result, head losses became so significant that the water did not arrive as expected.

Consequently, the desalination plant could not produce the expected amount of water.

In just a few weeks, these larvae become hard-shelled organisms.

This increases the “wall roughness” of the pipe, creating resistance and head loss.

Cases where the effective diameter of a pipe was reduced by 30%.

When you can’t get enough water into the plant, you simply cannot meet your production targets. It is a physical bottleneck that starts long before the water reaches a single membrane.

As illustrated in the sketch below by one of the world’s leading experts in intakes & outfalls (remember our course ;)), Eloy Pita from Increa, the scenario suggests that the piezometric level (shown in green, representing the worst-case condition) is actually lower than expected. As a result, water would either not flow (or would flow at a reduced capacity) from the intake riser to the lifting pump station.

The unintended consequences of chlorination

A loyal member of our community, Ms. Guadalupe, who operates a desalination plant in Spain, once told me they had serious biofouling issues in their membranes.

Interestingly, the problem disappeared when they stopped applying shock chlorination at the intake, which had originally been used to control marine fouling inside the intake pipe.

Instead, they chose to invest in divers and frequent mechanical maintenance, as they found it to be the most cost-effective life cycle solution.

However, Harry shared a perspective that many operators struggle with: the balance between the intake and the membranes.

If you have an intake already full of marine life and you start a heavy chlorination program, you end up killing that organic material and releasing it into the water.

This dead organic matter often causes more fouling downstream on the RO membranes.

It shouldn’t be a choice between a clean pipe or a clean membrane.

The goal is to understand the local biology well enough to maintain a clean system from the very start without overloading the downstream process.

The previous case made me curious, as I was not entirely sure about the relationship between chlorination and membrane biofouling.

So, I asked our friend Arian Edalat, and he told me:

He also recommended a book by what is probably one of the world’s leading experts on the subject, Nikolay Voutchkov (and, by the way, I was honored to receive a LinkedIn connection invitation from him a few days ago!).

Moving beyond “copy and paste” engineering

One of the biggest hurdles we discussed is how we design these plants.

I remember asking a process engineer in a previous project:

“How do you size chlorination dosing in different projects?”

He replied:

“It is mostly standard practice, based on common industry norms. In many cases, it is directly requested by the end users in the RFP.”

So, we simply request the equipment from approved vendors, sometimes for projects where the investment reaches the scale of millions. I remember thinking: what a great business for those companies…

Typically, a developer or utility follows a standard template: they buy a large electro-chlorination unit and hope for the best.

Harry advocates for studying local conditions during the feasibility or environmental study phase.

By understanding the specific species and their breeding cycles, we can design dosing systems that are much smaller and more efficient.

This saves on CAPEX and prevents the scaling issues often caused by over-dosing.

We need to stop seeing biofouling prevention as an “add-on” and start seeing it as a core part of the design.

Anyway, as the current reality is that many of us are—and will continue to be—facing the design, procurement, installation, and testing of these systems, I leave you here with a webinar where you can take a look at what these systems actually look like:

The human barrier to innovation

When I asked Harry about the biggest barriers to better solutions, he didn’t point to technology. He pointed to human behavior (what else…).

Many people in our sector are resistant to change because “this is how we have always done it.” There is also a fear of admitting that a current system isn’t working.

Working as a consultant in this space requires a lot of “emotional intelligence.”

You have to show operators and owners that there is a better way without making them feel at fault for the current situation.

It is about creating a win-win scenario where the plant runs more reliably and the operator has fewer headaches.

Whether it is a project in Saudi Arabia or Spain, the technical challenge is often easier to solve than the cultural one.

European Desalination Society

Harry and I will be in Marrakech on June 2026 in Euromed, he has a couple of sessions, so I look forward to meeting him, as well as any other reading this and may be there, write me in!

Desalination Plant in Barcelona

Last year at the AEDyR (Spanish Desalination and Reuse Association Congress), there was a very interesting technical session on this topic.

One case presented described a plant that experienced a massive proliferation of organisms—specifically mussels—within its intake system.

The accumulation of biological material caused occasional pumping shutdowns due to the reduction of the water passage section, reaching critical safety levels for the pumps.

These are gregarious organisms (they accumulate on top of one another), resistant to chlorination, and their growth is favored by a constant flow rich in nutrients and oxygen.

Various strategies were described to combat fouling in the intake pipelines:

• The use of divers.

• pigging systems (internal mechanical cleaning, next Tuesday specific episode about this).

• the use of ROVs (remotely operated vehicles) equipped with tools for inspection and pipe scrubbing.

Other preventive measures such as:

• Dosing of sodium hypochlorite (chlorine) and air. Shock chlorination treatments of up to 15 ppm for 24 hours.

• Application of anti-fouling coatings (rich in copper and nickel) on the intake windows and the first meters of the intake tower, where there is more light and a higher tendency for organisms to attach.

• Microbubble screens around the intake to prevent contaminants and organisms from reaching the system, a technique imported from the salmon farming industry.

• Ultraviolet light treatments at the intake system.

Al-Khafji Solar Desalination Plant

I talked to Harry about this plant that they have as project references to assess biofouling.

Back in 2014, the project came with requirements far beyond what we were used to—long intake and outfall pipelines, complex hydraulics, and demanding performance expectations, redundancy criterias, oversizing aspects, etc.

When we put the numbers together, the estimate reached around 120 million dollars for a 60 MLD plant.

My proposal manager looked at me and said, “120 m$ for 60 MLD? That rate is out of market! I prefer not submitting a bid, it will jeopardise our reputation!”

It felt like we were completely out of the game. And yet, we went ahead and submitted.

When the results came back, we were L1, by a significant margin.

Mmarkets don’t always behave as expected, and that sometimes what looks “too expensive” is simply a more realistic reflection of the challenge in front of you.

Thank you!

These past few weeks, the momentum has been real.

We’re seeing more and more interesting people joining the community, many of you actively sharing valuable insights, technical knowledge, and business perspectives.

I especially enjoy how the networking chat is evolving, real conversations, collaboration opportunities emerging, and even roles and career moves starting to flow organically.

This is exactly the kind of ecosystem we hoped to build: a place where water professionals from around the world can connect, learn, and create value together.

I’m genuinely excited about what we’re building, and even more about where it can go if we keep this energy and generosity.

Next Sunday, we shift gears into a key topic: DIGITALISATION.
Get ready!

Thank you to Harry, as well as to Patricia González and Catalina Iglesias, for helping me get this learning piece done.

*Note: Due to a cloud recording issue, from minute 18:00 onward you’ll notice no captions and lower audio quality, as I had to rely on a backup cloud file instead of the high-quality recording. Apologies for the inconvenience!

It appears on the courses in risk management, ethics, and infrastructure governance.

Following our hydropower episode released last Sunday, it’s a story I find fascinating, I’ve also watched the film (only found the spanish version as uploaded above).

I’ve written about the story, which caused probably the biggest tsunami on earth (it seems it reached 250 m height wave…) and its lessons, and surprisingly (or not), many of the takeaways still hold true today.

This is what many stakeholders, decision-makers, and entities face in water today. Accountability is often diffused across many areas, as this story clearly shows.

There’s a Spanish saying, “Entre todos la mataron y ella sola se murió,” which is roughly equivalent to the English idea of “Everybody’s responsibility becomes nobody’s responsibility.”

I hope this piece of writing helps you see above the fog, gain a clearer view of how things sometimes work, and reflect on what we can do to improve.

What happened

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We had UPS systems, so a few minutes passed without major disruption.

Then I started hearing that there was no electricity in other cities from messages I was receiving.

The first person that came to mind was José Manuel. I opened LinkedIn and sent him a message, and he replied shortly after.

It was in Spanish, but interestingly, within just a few minutes, José Manuel already had a very clear idea of the origin of the blackout, while the media and political discussion took weeks of “we need to investigate” and “we are looking into it”.

As José Manuel also pointed out, we are pro-renewable, pro-hydropower, pro-batteries, and pro-nuclear, but always with the understanding that each has its own role, mix, and constraints.

A national blackout is something you have to experience to fully understand.

because in many areas it depends on electric pumps. In fact, many parts of the city were without water, and people were queuing in supermarkets to buy bottled water, without even asking the price…

Our workshop

So, in the workshop we held with José Manuel and SENER, as one of the most reputable teams worldwide in hydropower and pumped storage (no doubt about this fact), we focused the discussion first on how the energy market actually works, what happens with high shares of renewables, and then on building a clear visual understanding of what that “giant battery” really is in a reverse pumped hydro system.

The energy transition is often framed through installed capacity targets and technological progress.

However, the real transformation is happening at a deeper level:

the way electricity systems must operate under increasing shares of variable renewable energy, particularly solar and wind.

What emerges is a system where the central challenge is no longer generation, but integration.

And within that challenge, hydropower, especially in its reversible pumped-storage form, is our player :)

The duck curve

One of the most illustrative concepts in modern power systems is the “duck curve,” which describes the mismatch between solar generation and demand over a typical day.

At midday, solar PV floods the system with energy, often exceeding demand. This creates a deep valley of net demand.

Then, as the sun sets, solar generation collapses while consumption rises sharply, requiring fast and flexible ramping from other sources.

But as discussed in the sector, this curve is becoming more extreme. It is no longer just a “duck,” but something closer to a cliff.

The midday oversupply is increasingly accompanied by price collapses, while the evening ramp becomes steeper and more operationally stressful.

“Receiving the PV”

A key operational insight from system operators is that the challenge is not simply producing solar energy, but receiving it.

When photovoltaic production peaks, the system must have somewhere to send that energy.

If demand is insufficient and storage is unavailable, the system is forced into curtailment or near-zero pricing conditions.

In other words, solar generation is not limited by sunlight, but by the system’s ability to absorb it.

This is why flexible assets, pumped hydro, batteries, and responsive demand, are becoming essential. They are the infrastructure that allows PV to actually be integrated.

The economics of zero-price hours

A consequence of high solar penetration is the increasing frequency of hours with extremely low or even zero electricity prices.

In some scenarios, investors in renewable assets discover that a significant portion of future revenue is concentrated in fewer and fewer hours.

In extreme cases, a plant designed under traditional assumptions of 2,000 operating hours per year may find that a meaningful share of those hours are now worth zero euros per megawatt-hour.

This leads to a paradox: investment in renewable capacity continues, but the marginal value of energy during peak production periods declines sharply.

In practice, the system compresses value into narrower time windows, and profitability becomes increasingly dependent on flexibility and timing rather than volume.

This is why planning horizons matter so much.

Hydropower and pumped storage

In this context, hydropower and pumped storage may act as the system’s natural stabiliser.

Pumped storage systems absorb excess energy when prices are low, often during midday solar peaks, and release it when the system is tight, typically in the evening.

This makes them the ideal complement to solar generation, which follows the opposite pattern.

Unlike batteries, which are typically limited to shorter durations, pumped hydro provides large-scale, long-duration storage.

It is, in many ways, the only technology currently capable of shifting energy across daily and multi-hour cycles at system scale.

Spring is coming, when water becomes the competitor

Jose Manuel wrote a few weeks ago “spring is coming” as the renewable game of thrones.

During wet periods reservoir levels rise and natural inflows are abundant.

Over the past two springs, photovoltaic generation has been capturing significantly less value, and 2026 does not look set to improve.

Spring combines lower electricity demand with rapidly increasing solar production. Year after year, more PV capacity enters the system precisely when consumption is weakest, leading to midday oversupply.

The result is clear in the market: frequent zero or negative prices, increasing pressure on PPAs…

Average captured prices have dropped from €72/MWh in spring 2023 to just €17/MWh in spring 2025.

And high hydropower output in recent springs has added further supply, concentrating competition among renewables in the same hours.

In 2026, the system enters with an additional 8 GW of solar capacity installed in 2025.

The consequence is increasingly persistent: solar-hour prices tending towards zero for long periods during spring.

Around the world

China is not hesitating in investing heavily in this water infrastructure.

The Fengning Pumped Storage Power Station in Hebei Province, China, is the world’s largest pumped-storage hydroelectric plant, with a total installed capacity of 3,600 MW.

As of December 31, 2024, the facility became fully operational following the commissioning of its 12th and final turbine unit.

In US, Jose Manuel published a few days ago about this interesting project.

LG&E and KU Energy LLC, subsidiaries of PPL Corporation, have partnered with Rye Development to evaluate a 266MW pumped storage hydropower project in eastern Kentucky.

If completed, it would be the first pumped storage facility in Kentucky and among the first new projects of its type built in the US in more than three decades.

“Pumped storage hydro has been used for decades around the world, and we’re proud to be part of an effort that could introduce it here in Eastern Kentucky.”

The proposed facility would operate as an eight-hour storage system, generating up to 266MW of electricity by cycling water between two reservoirs at different elevations. The project is intended to provide dispatchable capacity during periods of peak demand.

“Large-scale energy storage systems like Lewis Ridge not only strengthen the grid; they are significant long-term investments, providing economic benefits to communities and stabilizing energy prices for decades,”

Rye Development estimates the project cost at $1.3bn, including $81m in funding from the US Department of Energy. Construction is expected to support approximately 2,300 jobs over four years and generate around $1.65m annually in local tax revenue once operational.

The project received a preliminary permit from the Federal Energy Regulatory Commission in 2022 and is currently progressing through the federal licensing process.

Construction could begin in 2027, with commercial operation targeted for 2031.

The utilities currently operate more than 7200MW of generation capacity across coal, natural gas, solar and hydro assets, including the Ohio Falls and Dix Dam hydro plants in Kentucky.

So…

I personally really value this type of infrastructure.

Water and hydropower are among the oldest renewable energy sources humans have developed, and they remain a fundamental part of any country’s energy portfolio.

In some countries such as Brazil, Venezuela, Ecuador, and Norway the water–energy nexus is especially evident.

In these cases, energy security is tightly linked to hydrological conditions: when rainfall is scarce, hydropower output drops, which can directly lead to energy shortages and even blackouts.

At the same time, in regions with strong solar and diversified renewable mixes, pumped-storage hydropower can act as the “giant battery” the system needs, storing excess electricity and releasing it when demand peaks or when solar and wind are not available.

Soon, I’ll also share a specific insight on the relationship between nuclear energy and water, another highly relevant and increasingly discussed topic.

Thanks for being there!