water
Let an agent treat water as a substance with a source and a quality rather than an undifferentiated supply, and decide whether a particular water may be drunk, used or discharged.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify
Researched by: Claude
Purpose and description
Let an agent treat water as a substance with a source and a quality rather than an undifferentiated supply, and decide whether a particular water may be drunk, used or discharged.
The compound of hydrogen and oxygen that is liquid at ordinary temperatures, essential to all known life, and the substance most human infrastructure exists to move, hold and treat.
What it is for: Sustaining life, and in use: drinking, washing, cooking, cooling, transport and carrying away waste.
It can be drink it, if its quality allows; wash and clean with it; heat and cool with it, which is most industrial use; move it through pipes, channels and vehicles; contaminate it, which is the failure that matters; treat it, moving it between qualities.
Distinguishing features
A pure compound, so its constants are fixed and its quality is entirely what is dissolved or suspended in it
Drinking, process, waste and environmental water are four regulated categories of one substance
Quality is a claim about a sample at a time, never a property of a supply
What it looks like
Colourless and transparent in small quantity. Colour in a body of water comes from depth, suspended matter and what lives in it, not from the water.
Physical character
freezing point: 0 C - pure, at standard pressure
boiling point: 100 C - falls with altitude, which matters for disinfection by boiling
density: 1000 kg/m3 - maximum near 4 C, which is why ice floats
household use: 100-200 L per person per day - varies by region more than by anything else
How it is recognised
Clarity says little about safety: dangerous water can be clear and safe water cloudy
Source and treatment history identify a water, and neither is visible
State - ice, liquid, vapour - is the one thing appearance settles reliably
Related models
is a kind of - inherits composition, purity and hazard questions
needs - in human use it is inseparable from what delivers it
regulated by - decides what may be supplied as potable
is confused with - a lake is a place; water is a substance
In practice
Families and kinds
by regime: potable, process, irrigation, waste, environmental
by source: surface, ground, rain, desalinated, recycled
by treatment: raw, filtered, disinfected, demineralised
by state: ice, liquid, steam
Identifiers
CAS 7732-18-5 names the compound, not any particular water
supply zone identifier utility-specific the unit quality is actually reported against
Standards and regulation
WHO Guidelines for Drinking-water Quality, from which most national standards derive
National drinking water regulations, which set enforceable limits and monitoring
Discharge consents, which govern what may be returned to the environment
Failure modes and hazards
Microbial contamination, the fastest-acting and most common failure
Chemical contamination, including from the pipes rather than the source
Scarcity and interruption, which makes everything downstream fail at once
Scalding and drowning, hazards of the substance rather than its quality
Also called
+86
Where this came from
wikidata · CC0 1.0
Also registered as vr.tr.water-food
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.
Quality and fitness for a use What is in this water and what that permits.
The same water is fit for one use and unfit for another, and a single quality flag hides that.
What is in it
Dissolved and suspended content.
Contaminants and limits
What is measured, against what limit, by whom.
- What is measured in this water, at what concentration, against whose limit? measurement
- When was the sample taken, and what has happened to the supply since? provenance
Fitness by use
Potable, process, irrigation and discharge.
Use-specific acceptance
Which uses this water is currently fit for.
- Which uses is this water fit for, and which is it not? boundary
- What must an agent refuse to permit on a general quality claim alone? action
Source and treatment Where it came from and what was done to it.
Treatment history explains both what is absent and what the process itself introduced.
Source
Surface, ground, rain, desalinated or recycled.
Source and its typical burden
Where it came from and what that implies before treatment.
- What is the source of this water, and what contamination is typical of it? definition
- How is the source recorded and verified? provenance
Treatment
Processes applied and what each removes or adds.
Treatment train and residuals
What was done and what the process leaves behind.
- What treatment has this water had, and what does each stage remove? definition
- What does the treatment itself add, and is that within limits? measurement
Delivery, storage and continuity How it arrives and what happens on the way.
Most water problems in practice are problems of the pipe, the tank and the interruption rather than of the source.
Conveyance
Pipes, channels, tankers and what they contribute.
Conveyance effects
How delivery changes the water.
- How is this water delivered, and what does the conveyance add or remove? definition
- Which materials in the system constrain what may be supplied through it? boundary
Continuity of supply
Interruption, pressure and what depends on both.
Interruption and consequence
What fails when supply stops, and how fast.
- What is the continuity of this supply, and what interruptions are recorded? measurement
- What must an agent arrange ahead of an interruption that is already known? action
Discharge and environment What happens to it after use.
Water leaves as waste, and the rules about leaving are stricter than the rules about arriving.
Waste water
What use added and what must be removed before return.
Discharge quality
What may lawfully be returned, and where.
- What does this use add to the water, and what limits apply to returning it? definition
- Under whose consent is discharge permitted, with what monitoring? provenance
Environmental effect
Abstraction and discharge as effects on a place.
Effect on the receiving body
What taking and returning water does where it happens.
- What effect does abstraction or discharge have on the receiving environment? measurement
- What must an agent refuse to plan because of that effect? action
What the second pass must settle
- How should the model separate the substance from the supply, given that quality claims belong to the supply?
- What is the right unit for a quality claim: the sample, the zone, or the moment?
- How should recycled and desalinated water be represented when regulation treats them differently from the same water by another route?