A lake keeps everything it is given.
Water that stays put for years is water where this summer's decision is still in the basin in 2033, and where treatment held in place year round compounds instead of evaporating.
How a lake differs from a bay
No tide, no flush, no second chance at the same water.
A coastal basin exchanges part of itself twice a day. A river reach has replaced its volume by Thursday. A lake does neither. Inflow and evaporation are the only doors, and in a deep basin the water arriving this spring may not leave within the career of the engineer responsible for it.
Two consequences pull in opposite directions. A lake accumulates: nutrients, metals, salts and organic material that arrive are filed instead of carried away. And a lake holds a result. Treated coastal water is partly next door by tomorrow; treated lake water is still there, still yours, still measurable, so a before-and-after is possible.
Then the season arrives. Surface water warms, a thermocline sets up, and the layer beneath it stops exchanging with the atmosphere. Everything decomposing down there keeps consuming oxygen and nothing replaces it until autumn turnover. That sealed lower compartment fails first, and no surface aerator, fountain or paddlewheel has ever reached it.
So a lake is worked by depth. The layer under the thermocline comes aboard and goes back to the same layer after the reactor, with draw and return depths taken off the temperature and oxygen readings down the column, on the day. The first thing we ask for is a profile.
The order it goes wrong in
Four failures, and the one that reaches the public is third.
Lake managers rarely get called about the first two. They get called about the third, by which point the fourth is already being drafted.
- The deep layer runs out Oxygen under the thermocline falls through the summer with nothing to restore it. Fish leave the cool water they need and crowd into warm water they cannot use for long. Nobody photographs this stage.
- The bloom takes the surface Warmth, light and available nutrient produce a mat that changes the color of the whole basin, visible from a satellite, a bedroom window and a boat club car park in the same week.
- The intake and the beach Taste and odor compounds reach a drinking-water treatment plant, or a toxin reaches a swimming area. In August 2014 a bloom on Lake Erie reached Toledo's intake and about half a million residents were advised not to drink the tap water.
- The notice Somebody signs a document, and a water-quality problem becomes a political one. The person holding the pen will want to know who took the readings and whether anybody independent saw them.
The published freshwater record
The strongest result on record for this class of treatment is eight acres.
Eight acres. Fresh water. Another company's equipment.
In 2018 NOAA's National Centers for Coastal Ocean Science validated an ozone nanobubble aeration system on a pond near Fort Myers Beach in Florida, reporting algae eliminated inside 48 hours, oxygen properly restored and no apparent harm to the aquatic life in it. Roughly three hectares.
Between three hectares and a working reservoir lies real engineering distance: wind fetch, depth, inflow, basin shape, and how much of the volume has to be turned over to hold a result. That last one is answered by fleet sizing, and commercially by whether the reservoir's worth to its owner carries the hulls it would take. Nobody in this business holds a published result at reservoir scale.
A lake program therefore opens with a calibration phase sized between the two: a bay or an arm of the basin, viability parameters agreed in writing before a hull moves, and a result that misses them closing the phase. The institution holding the live feeds sees those readings as they land, which is what makes the number worth carrying to a board.
Who you are actually dealing with
On a lake, the owner and the regulator are often two doors apart.
Coastal work means a coalition in which nobody can commit the others. Lakes are usually simpler and occasionally harder. A municipal water utility, a dam operator, a lake district, a national park authority or a private estate tends to hold the abstraction license, the recreation season and the compliance obligation on the same desk.
So lake decisions can move quickly once they move at all. They also stall, because one office carries the whole political risk of trying something, with no partner to share the explanation if it disappoints.
The arithmetic is unusually clean. A basin that files everything it receives gets harder to treat every year it is left alone. Material dealt with steadily, in the quiet months, never becomes the mat that shuts a swimming area or the taste-and-odor complaint that reaches a treatment plant with a journalist behind it. The subscription runs through the year, and is priced as service. A rescue is the same equipment bought in the worst week of the worst month.
The compensating advantage is the record. Lakes are the best-monitored water bodies on earth: somebody has usually sampled the same stations monthly since the 1980s, and a university has built a career on the dataset. We ask for that institution by name at the site read, to take the crew's live stream for the whole program. The second treated year shows whether the lake is drifting the right way.
Where a different instrument is the right one
Four lakes that need something other than a vessel.
The site read checks for all four in week one.
- A lake whose inflow nobody can point at. Where the loading arrives at a hotspot, a firewall can sit on it. Where it seeps off a whole watershed and nothing on the water needs protecting meanwhile, in-water work buys nothing worth its price, and the money belongs on the land.
- A lake that is drying. Falling levels turn the problem into exposed lakebed and airborne dust, a land duty. That work sits with SoilScrubber: a different vehicle, crew and regulator.
- A reservoir where the fix is engineering. Where the outlet works can draw from a different depth, or aeration can be installed permanently at the dam, a fixed asset usually beats a contracted fleet. Fluid Nano covers the mounted version of the same treatment stage.
- A lake with no owner of record. Until a body will hold the record, agree the parameters and put its name against the oversight, a program has nowhere to report, and improving the water does not settle that.
Asked at every first meeting
Four about lakes specifically
Where has this worked on a water body like ours?
The nearest published result is the eight-acre Florida pond NCCOS validated in 2018, on another company's equipment.
So the calibration phase comes first, with parameters signed by both sides before a vessel moves and the institution holding the readings named in the same document.
Will treatment stop the blooms coming back next year?
Not by itself. Nutrient already in a lake keeps cycling long after the inflow is reduced, so the catchment answer takes decades and still has to be started.
The subscription holds the condition of the water through every month while that runs, because a basin left alone starts accumulating again from the day the last hull leaves. Where the load enters at a hotspot, the firewall can go on the inflow itself. Dr Peter Moeller of NOAA saw an effect on nitrogen and phosphorus in this work; we are still studying it, so no figure is published.
What about a lake used for drinking water?
Then the drinking-water authority answers the compliance question first. Any oxidative duty near a raw water intake is agreed with that authority in advance, and its figure is the one the service level agreement carries and the inline instruments hold to.
What is consented is a discharge with a figure on it: water treated in a closed reactor aboard and returned to the same lake. Nothing is impounded on the hull. We expect that discussion before the commercial one, and arrive with the method statement and discharge plan written.
Who would hold the data on a lake program?
Whichever institution already answers for that lake: a university limnology group, a water authority laboratory, a lake district's own scientists.
They hold the live feeds our crews steer by and keep them once the last hull leaves. Set against thirty years of their own sampling, a treated year is something your board can check without us in the room.
Bring the depth profile
Send us the lake and its depth readings.
Volume, maximum depth, when the thermocline sets up and breaks, and what the last three summers did to the intake or the beach. If somebody has sampled it for thirty years, tell us who.