Nothing is built, nothing is owned, and nothing is left behind.
That sentence is either the most attractive or the most alarming thing about in-water remediation, depending entirely on which appraisal template an institution reaches for first.
Water finance is built around structures. Plants, networks, reservoirs, interceptors, treatment works: assets with a book value, a design life and a decommissioning obligation. That template has moved an enormous amount of capital, and it is the correct instrument for the source of nutrient pollution.
It is the wrong instrument for the condition of a receiving water body during the decades that source work takes. Applied there it produces a familiar outcome: a proposal appraised against criteria it was never designed to satisfy, failing on residual value and asset security rather than on whether it delivers anything.
So it is worth putting the two side by side properly.
Comparison
Two instruments, both legitimate, doing different jobs.
| Dimension | Catchment capital works | In-water remediation |
|---|---|---|
| What is acquired | Structures, land, easements, network | Contracted capacity in a defined volume of water for a defined window |
| Time to first benefit | Years to decades, after construction and behavioural change upstream | Within a season, measurable on instrumentation during the same window |
| What it solves | The source of nutrient and sediment loading — permanently, if sustained | The condition of the receiving water — temporarily, and only while contracted |
| Reversibility | Low. Built infrastructure commits a corridor and a budget for decades | High. Capacity can be scaled, relocated or stopped between seasons |
| End of term | Residual value, handback condition, decommissioning liability | No residual asset, no handback, no decommissioning — and no security either |
| Underwriting basis | Physical asset and regulated revenue | Contracted service and measured outcome, which requires verification design |
| Principal risk | Construction, cost overrun, upstream compliance over decades | Efficacy at scale in open water, which is currently unproven in public literature |
The last row is the one that matters, and it is stated here rather than buried in an annexe. See the diligence position further down this page.
Precedent
Water services have industrialised before, and quickly.
The scepticism an operating water service attracts on cost grounds is worth testing against the recent history of the sector it sits in.
The World Bank reports that the cost of desalinated water has fallen from around US$5.00 per cubic metre in the 1980s to as little as US$0.40 to US$0.50 in recent projects. That is roughly an order of magnitude, driven by membrane development, energy recovery, scale and operating discipline rather than by any single breakthrough.
Operating discipline alone can move remarkable amounts. Dubai's water authority cut non-revenue water losses from 42 per cent in 1988 to 4.6 per cent by 2023 — a change in what a utility manages, not in what it builds.
Neither precedent proves anything about in-water remediation costs. What they establish is that the appraisal instinct to treat a novel water service as permanently expensive has been wrong before, in this exact sector, within the professional memory of the people doing the appraising.
Demand
The addressable problem is growing on a documented curve.
Diaz and Rosenberg's 2008 study in Science counted more than 400 coastal hypoxic zones worldwide, covering roughly 95,000 square miles, and found the count had approximately doubled every decade since the 1960s. Few environmental trends are that clean, and none of them are encouraging.
The Baltic is the instructive case for anyone modelling how long a regional recovery takes. Across 1961 to 2005 its hypoxic zone averaged something like 50,000 square kilometres of bottom water below 2 millilitres of oxygen per litre, with substantial seasonal and inter-annual variation. That is a semi-enclosed sea with nine states on its shores, decades of monitoring and one of the longest-running coordinated nutrient efforts anywhere.
An institution planning across decades should read those two facts together. Demand for this capability is not speculative, and the alternative pathway is slow even where governance is strong and money is available.
Sources: Diaz and Rosenberg, Science, 2008 · Conley and colleagues, Environmental Science and Technology.
What no instrument in this class fixes
Boundaries first, because an allocation made on an inflated scope produces a write-down and a reputational problem at the same time.
Ocean acidification is not addressable by any vessel programme. NOAA reports aragonite saturation state falling by about a fifth since the pre-industrial era across much of the ocean surface, and its own dataset puts the working numbers plainly: above a saturation state of 3, calcifying organisms are more likely to survive and reproduce; below 1, aragonite shells begin to dissolve. Local pH support inside a bounded nursery or hatchery intake is real and defensible. Reversing a basin-wide trend is not on offer from anybody.
Basin-wide marine heatwaves are the same category. Bleaching-level heat stress affected 21 per cent of reefs in the first global bleaching event of 1998, 37 per cent in the second, 68 per cent in the third and 84 per cent in the fourth. In-water cooling addresses local hot spots. It does not address the trend those figures describe.
And nutrient loading is generated on land. It will be reduced on land, by agriculture and wastewater capital, or it will not be reduced. A national programme that funds in-water work while abandoning catchment reform has bought itself time and then wasted it.
The diligence position, in full
Institutional capital will commission technical and commercial diligence on this. Below is what that exercise finds, including the parts that do not help us. We would rather an adviser confirmed our own account than discovered a gap between it and the record.
What is established
Nanobubbles are a characterised class of object rather than a marketing term: gas-filled bubbles below roughly 1,000 nanometres, with high stability, negative surface charge, very high specific surface area and enhanced gas–liquid mass transfer. The performance consequence has been measured in peer-reviewed work. None of that is proprietary to us, and none of it is contested.
What is validated, and by whom
Two NOAA National Centres for Coastal Ocean Science validations exist in this space: a freshwater algal remediation trial at pond scale in 2018, and a ballast-water invasive-species evaluation in 2020. Both name other companies' technology and other partners. They support the approach and its safety at those scales. They do not validate any particular vessel, and any document presenting them as company-specific validation is misrepresenting them.
One trap in that 2020 release is worth naming before an analyst walks into it. The system it describes is another party's Nanobubble Ozone Technology, which shortens to NBOT — the same four letters this network uses for Nano Bubble Oxidation Technology. Two different systems, two different owners, one abbreviation. A citation that leans on the collision is either careless or deliberate, and neither is a good sign in a data room.
What only the operator can attest
Alarivean holds a Cooperative Research and Development Agreement with NOAA. Agreements of that kind are not published, so there is no filing to pull and no register to search, and a diligence exercise that treats the empty search as a red flag has misunderstood the instrument. Under it, work with the NOAA scientist Dr Peter Moeller addressed inorganic toxins: the treatment sterilises them by disabling the functional groups responsible for the toxicity, which is a different result from precipitating a metal out of solution. Say what that is and is not. It is a research relationship with a federal science agency. It confers no endorsement, and we would object to a document that implied one.
What is unresolved in the science
Whether nanobubbles themselves generate hydroxyl radicals is genuinely disputed. A 2020 study from Moleaer and Arizona State University reported reactive oxygen species including hydroxyl radicals from injected nanobubbles. A controlled 2023 study by Chae, Kim, Kim and Fortner in ACS ES&T Engineering found generation to be minimal, if it occurred at all, under the ambient conditions tested. Programmes should be built on the mass-transfer result and the engineered oxidation stage, both of which are measurable, rather than on radical chemistry a reviewer can reasonably challenge.
What our own diligence could not confirm
Unverified claims in the operating company's public material
- An $11 billion figure for Lake Erie property-value loss. The NOAA Fisheries material we can retrieve cites $10.05 million in lost shoreline property-value services for the 2014 event — four orders of magnitude apart, and we use the smaller documented figure.
- A $2.5 trillion annual value for ocean goods and services attributed to the World Bank, which we could not verify against a primary World Bank source. The OECD figures used on this site are what we can stand behind.
- Vessel infusion rates of 4,000 and 2,000 gallons per minute, which are company-stated. No independent test report, regulatory filing or third-party measurement was located.
- A repeated citation to "Tabla-Hernandez et al., 2020" supporting pollutant-precipitation claims, which we could not locate in academic search.
What the field record actually is
In September 2024 Alarivean, Inc. of Scottsdale, Arizona received Florida Department of Environmental Protection permit FLOA00062, issued under Chapter 403 of the Florida Statutes with a five-year window, to field-test an ozonated-seawater craft for red tide mitigation, conditioned on active Karenia brevis above 100,000 cells per litre. The Sarasota Bay Estuary Programme and the Florida nonprofit START both documented it independently. The estuary programme has said publicly that open-water efficacy is not yet proven, and that remains true.
The framing an institution should take from that is the operator's, offered as such. On Alarivean's account the estuary programme backed the permit application with technical input and, deliberately, with none of its own funding — the deliberate part being the funding, since a body that has paid for nothing is free to publish whatever the water turns out to show. It has put no evidence on the record against efficacy. What it wants is the measuring role in open water, so that any endorsement reaching past the bay is built on data its own people gathered. That is the position we want it to hold. And it defines the next evidence step precisely: instrumented open-water work, with the local science body reading the results.
Meanwhile a permit to test is not evidence of scale, and an institution should structure accordingly: assessment, then bounded calibration with pre-agreed viability parameters, then contracted capacity, with a genuine option to stop after each.
Sources cited on this page
- World Bank — From scarcity to sustainability: the GCC's journey towards water security, March 2024.
- Diaz and Rosenberg, Science, 2008 — global count of coastal dead zones.
- Conley and colleagues — Baltic Sea hypoxia extent, Environmental Science and Technology, 2011.
- NOAA Ocean Acidification Program — acidification is more pervasive than previously thought, for the fifth decline in aragonite saturation; and NOAA Science On a Sphere — the saturation-state dataset, for the values of 3 and 1.
- NOAA Coral Reef Watch and ICRI — the global bleaching event comparison across all four events, and the bleaching alert levels keyed to Degree Heating Weeks.
- Chae, Kim, Kim and Fortner — reactive oxygen species generation from nanobubbles, ACS ES&T Engineering, 2023.
- NOAA NCCOS — freshwater HAB validation, 2018 and ballast-water validation, 2020.
- Sarasota Bay Estuary Programme and START — public documentation of FDEP permit FLOA00062, 2024. Operating company material at alarivean.com.
Oversight as an underwriting term
The record has a custodian who is not us.
Every programme is built with continuous independent oversight inside it, and on an instrument underwritten against measured outcome that is not a governance nicety. It is the security.
Alarivean insists that relevant local scientific bodies are engaged for the life of a programme, with access to every water-quality feed the operator works from and to any others those bodies bring themselves. Human and environmental safety sit ahead of throughput in the risk controls, and somebody outside the company has to be positioned to say whether that held on the day.
For a committee, this is the line between a fundable service and a services contract taken on trust.
- Continuous, not bookended Not a consultation at mobilisation and a report at handover. The engagement runs through every season the vessels are in the water, including the quiet ones.
- Live feeds, not a digest The oversight party reads the same instrumentation we read, at the same moment we read it. A quarterly summary compiled by the supplier is a different product wearing a similar name.
- Local, because local is answerable A university department, a fisheries institute, an estuary programme — bodies that already carry a reputation in that jurisdiction and will still be carrying it in year six.
- Custody, which is where these instruments usually fail Outcome-based structures rarely come apart on the measurement. They come apart on who kept it. From the first treatment pass the record sits in more than one pair of hands.
- Required, not permitted A programme nobody independent is watching produces results nobody is obliged to believe. That is worth little to an investment committee and rather less to the minister who approved it.
From an investment committee
Five questions, answered without hedging
Where does this sit relative to catchment investment?
Alongside it, and second to it in permanence. Catchment work is the only durable answer to nutrient loading and should be funded on its own merits.
In-water remediation holds the condition of the receiving water across the fifteen to thirty years that work takes. Presented as a substitute, it is a false prospectus and should be refused.
What is the residual value at the end of a concession?
None, by design. No structure, no land, no plant to hand back or decommission, and therefore no stranded-asset risk and no residual-value negotiation.
The corollary is real: there is no physical security to underwrite against. The instrument has to be underwritten against a contracted service and a measured outcome, which puts unusual weight on verification design.
How is performance verified, and by whom?
In-situ profiles through depth at the point of treatment — dissolved oxygen, temperature, salinity, pH, turbidity — before and after each pass, with earth observation covering the wider zone.
Some of the standards already exist in public. NOAA Coral Reef Watch publishes an alert scale keyed to degree heating weeks: reef-wide bleaching risk from 4, mortality among heat-sensitive corals from 8, multi-species mortality from 12, and two further levels above that added in December 2023. Verification should sit with a party whose fee does not depend on the reading.
What did your own diligence fail to confirm?
Three figures, listed in full above: an $11 billion Lake Erie property number against $10.05 million we can document; a $2.5 trillion ocean-services figure we could not trace to a primary World Bank source; and vessel throughput rates that remain company-stated.
The NOAA cooperative agreement is not on that list and should not be. It exists, its text is private in the ordinary way, and an empty search result is what a private agreement looks like from outside.
We publish the list because an adviser will assemble it anyway, and the only question is whether they assemble it from our material or against it.
Who is watching the operator while the programme runs?
Local scientific institutions, continuously, reading the same live feeds we read and any others they choose to add. Alarivean requires this rather than allowing it, and it is written into the design of a programme rather than conceded during one.
The consequence for an allocator is narrow and worth a lot: the performance record is not held solely by the party being paid on it.
Structured staging
Fund the assessment before funding the programme.
The coastline, the exposed sectors, the horizon and the counterparty structure you would use. Alarivean returns a staged assessment with the uncertainty attached rather than removed.