Steps Ventures · treatment plant screen · North America and Europe
Every treatment plant on three continents where a process retrofit has a business case.And the 41,713 where it does not.
The finding
Anyone can pull the public permit files and sort treatment plants by flow. That list is wrong, and it is wrong in a way you cannot see from the flow.
A utility does not buy chemistry. It buys capacity it does not have to build, and an operation that stops causing trouble. So the question is not which plant has the largest chemical bill. It is which plant is close enough to its design flow, or fighting enough wet weather, that a capital project is already being discussed, and is still free to choose what to do about it.
All of that is on the public record, in three different regulatory systems that do not talk to each other and do not use the same units.
Four gates, and what each removes
Every gate is applied independently. A plant has to clear all four, because a strong number on one dimension does not make up for a disqualifying one on another. That is a filter, not a ranking.
Below 5 MGD a plant cannot fund a retrofit. Above 120 it has in-house process engineering and a procurement cycle measured in years.
Either the utility has filed a capital need with its regulator, or the plant is near its design flow, or it carries wet-weather flow its clarifiers were never sized for, or it is already failing to separate solids.
A lagoon has no sludge blanket to work with and no clarifier to defer. This is not a small exclusion: 679 of Quebec’s 879 stations are aerated lagoons or wetlands, against 113 on activated sludge.
A plant deep in enforcement already has a remedy specified and an engineer of record appointed. It cannot pilot anything.
Coverage
of 16,481 screened
of 23,987 screened
of 3,401 screened
32 countries. Four regulatory systems reconciled to one schema: the US permit and compliance record, the US capital-needs survey, the European reporting directive, and the Canadian effluent regulations plus Quebec’s own station file. They disagree on almost everything, including whether a plant is measured in flow or in population, and each is missing something the others have. Europe reports no combined sewers. Canada reports no design capacity. Only the US files a capital need in dollars.
What is already budgeted
Capital need the utilities in this list have already documented with their regulator, across secondary treatment, nutrient removal and combined-sewer correction. Not a market estimate. Their own filed numbers.
Qualified plants carrying a documented need. For the rest the case rests on capacity and sewer type, which are proxies for the same thing.
Plants with measured cold-month effluent temperature rather than an assumption. That measurement replaced a latitude proxy which, checked against it, missed 201 of the 281 genuinely cold plants.
Three things it corrected
An earlier version ranked on enforcement, on the theory that a plant in trouble buys fastest. It scored two known reference sites in the 85th percentile, which is to say it missed them. A plant deep in enforcement has a remedy specified and an engineer appointed. Enforcement now counts against.
Cold degrades settling through filamentous bulking below roughly 15 °C. But it is the wastewater that has to be cold, not the air. Measuring it directly showed the latitude proxy caught only 80 of the 281 plants that actually run cold, so the proxy is now a fallback and the measurement decides.
A single permit filed a placeholder flow that would have made it the second largest plant in the country. It carried more than a third of an earlier national total and it sorted first, which is exactly why it got checked.
Not on this page
The 2,156 plants. Their names, permit numbers, flows, capacity headroom, sewer type, receiving water and operations contacts. That is the deliverable, not the teaser.
I do this kind of screening work for water and energy companies selling into municipal and institutional buyers. The value is not the list. It is knowing which doors are physically closed before anyone knocks on them.
Mike German · mike@stepsventures.com
Sources and method
US: EPA ECHO Clean Water Act facility and compliance record, including combined-sewer flags, permit status and past-calendar-year average flow. Europe: EEA Waterbase reporting under the Urban Waste Water Treatment Directive, 13th call, 2023. Canada: Environment and Climate Change Canada effluent regulatory reporting, including the combined-sewer overflow register. All public. Population equivalent is converted to flow on a design convention, not a measurement, so cross-continent size comparisons inherit that. Screening grade throughout: every entry is a first call, not a qualified opportunity.