What settles a dose, and what stops one.
Each instrument settles one question. Any one voice can halt a pass, and outside institutions hold the record while it runs.
The layers
Four sources of truth, and they answer different questions.
The common failure is letting the most impressive layer answer a question it cannot reach.
Earth observation
Sets the search area and the priority order across a zone, days before a shore sample would notice anything. It cannot see under the surface, name a species or set a dose. HABscan covers where these products bend and why.
Moored instruments
Continuity at a fixed point: the overnight crash nobody was on the water for, and whether a treated volume held its gains a week later.
Profiles at the working site
Dissolved oxygen, temperature, salinity, pH and turbidity through depth, before and after the pass, at the same depths. This layer settles which depth to draw from and what the reactor runs. No other layer can substitute.
Samples and assay
Cell counts, toxin assay and the discharge parameters a probe cannot read, sent to an independent laboratory. Slow, and the only thing that answers what a bloom was carrying. A falling count is a weak proxy and is not the verification step.
On the day
The standard is written down before the vessel moves.
What is fixed in advance, and what stays adjustable, separates a controlled operation from an improvised one.
Fixed before departure
What the effluent has to meet at the outlet, agreed with whoever consents the work, set against a measured background, and written as a discharge limit in the units a regulator already inspects.
Decided on arrival
Which depth to draw from, how many passes, transit order across the tasking. All of it from the profile taken on site, because a water column three days old is a guess with a timestamp on it.
Settled ashore, held at sea
The standard. If the water needs more than it allows, the pass ends and a new plan is agreed ashore with the oversight party before anything resumes. An inspector can reconstruct this from the log.
Organic background decides a great deal. Oxidant is consumed by whatever is already dissolved before it reaches the target, so two bays with identical cell counts can need very different plans. It is measured at the intake on the day, and the figure goes into the log beside the pass it governed.
Stop conditions
Any one condition halts a pass, and so does any one voice.
The set is defined in writing before the first pass, while everyone is calm. Nothing in it is ranked. A single item stops the work.
Among them: a discharge assay outside the standard; dissolved oxygen at the outlet or around it moving the wrong way; a large animal at the bar-rack; an intake drifting into a mapped exclusion area; distressed or dead marine life near the vessel; and two instruments that ought to agree failing to, with nobody yet able to say which is wrong.
The inline interlocks cut the oxidant themselves, the fastest stop on the boat. The treatment operator, the master, the duty analyst ashore and the oversight scientists can each stop it too, without persuading anybody else.
All four have to agree before it resumes. Stopping is cheap and reversible, and continuing through an unexplained reading is neither.
Thresholds
The numbers a duty engineer actually needs.
Each value goes into an operating procedure with the qualifier its source attaches.
The value an alarm must never be set from
A figure of 0.5 to 1.0 mg/L circulates widely as an approximate lethal dissolved-oxygen threshold for fish, and it traces back to the same Delaware River Basin Commission review. It is a nineteen-hour result for juvenile White Perch alone, sitting in an appendix table. The review's own conclusion is the 4 to 6.4 mg/L band.
A night alarm set from the appendix figure would be an order of magnitude low, and the first sign of it would be dead fish. Program alarms are set against the review's conclusion, then against what the species and the season in that water demand.
Routing
Hull-hours are the scarce thing, and routing is how they get spent.
A zone rarely has one problem at one time. It has four, ranked badly.
Every morning: which water, in what order, for how long. The answer comes from the forecast, what has already been worked, what sea and weather allow, and what the crew and hull have left.
The output is a tasking, never written from yesterday's complaint. A program that spends its hours on the loudest item keeps arriving after the fact. The Deep Strike in the base subscription arrives before, tasked at whatever water the trouble is building in.
Data services
What a program produces, besides treated water.
A running program generates evidence either way. Designed in advance, the record holds up in the year something goes badly.
The pass record
Position and time, the depth drawn from and returned to, the throughput sustained, the duty the reactor ran, the readings on influent and effluent, and the profile either side. One row per pass, written as it happens, readable cold by a regulator who was never aboard.
The water-quality series
Continuous telemetry from moored instruments and vessel profiles, unbroken through the year, at fixed stations as well as treatment sites. Untreated control locations included, because a change without a comparison is an anecdote.
The zone risk surface
Forecast conditions across the contracted area for the coming days, from earth observation, in-situ data and meteorology. It drives tasking, and it is handed over so the client can plan around next week.
The program account
What was treated, where, when, and what the water did, against the parameters agreed at the outset, including the missed ones. The quiet months are reported too. Independent laboratory results sit inside it under their own dates.
The second copy sits outside this company
Independent oversight is an access arrangement, named in the program schedule with the date its feeds go live. Local scientific institutions, engaged for the life of the subscription, read the telemetry the duty crew steers by, at the same moment, and may moor instruments we have never touched. They start before the first pass and keep their copy afterward.
What that changes
Nothing, on a good day. On a bad one, the pass that missed, the patch that came back overnight and the assay nobody expected land on two desks at the same moment.
If a program's targets and the health of the water ever pull against each other, the institution can say so publicly and needs no sign-off from us. The documents behind a program are listed in one place.
Where the decision stays with a person
Three things the control layer leaves to somebody who signs.
Instruments narrow a question. They do not close it.
- It does not set its own limits. Interlocks can cut the oxidant without asking anybody. Deciding what the effluent must meet, and signing it, stays with a named person.
- It does not forecast a bloom with any useful precision more than a few days out. Risk surfaces narrow a search and rank a tasking. They do not reach from March into August.
- It does not replace your own monitoring obligations. Whatever a regulator requires of you, you still owe. Our feeds add to that record and are available to whoever you report to.
Asked by data teams and duty engineers
Four about the instruments
What dissolved-oxygen number should an alarm be set at?
Higher than the number that defines hypoxia. NOAA's 2 mg/L is a classification threshold, not a safe operating level, and treating it as one is how a stocked pen gets lost overnight.
The Delaware River Basin Commission review puts lethal-level requirements for sensitive estuarine species at 4 to 6.4 mg/L. Set against that band, then against your own species and season.
Who can stop a pass?
Any of four people, acting alone: the treatment operator, the master, the duty analyst ashore, or an oversight scientist.
The interlocks are faster than all of them, cutting the oxidant when a reading crosses the line. Restarting requires all four.
Does the oversight body get the raw feeds or a report?
The feeds. Live, as the crew sees them, plus any instruments they moor themselves.
An operator's summary and a telemetry stream are different artifacts, and only the stream can be independently checked.
Can a satellite decide what the reactor runs?
No. It sets a search area and a priority order, and stops there.
What the treatment stage runs comes from the profile taken on site and from the instruments watching the intake and the outlet, on the day.
Where the detail lives
Bring your monitoring people
Send the record you already hold.
With the water body and the season. The site read comes back with the stations we would want, the thresholds we would set, and the gaps in the existing data that would have to be filled first.