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Safety snapshot of mobile work before merging upstream chat-v2: - Qortino AI: QDN pack discovery/download (Q-Share ids), external app storage, install validation, teach/report Q-Mail, PDF thumbs+zoom - Android share target "Quitter" with native ShareReceiver plugin - Categorized device saves (Images/Videos/Audio/Documents/Apps/GO state) - createNamedFile helper: cordova-plugin-file clobbers global File Co-authored-by: Cursor <cursoragent@cursor.com>
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Water: Storage, Treatment, and Sourcing
Educational preparedness information. Water safety mistakes cause illness fast — when in doubt, treat twice (filter + boil or filter + chemical).
How much you need
Plan 4 litres per person per day minimum: 2 for drinking, 2 for cooking and basic hygiene. In heat, exertion, illness (fever, diarrhea), pregnancy, or for large people, drinking needs alone can hit 4-6 litres. A family of four needs ~112 litres for one week — most households store a tiny fraction of this. Two weeks per person is a serious baseline; grid-down water utilities can fail within hours to days when pumps lose power.
Storage that keeps
- Food-grade containers only (HDPE #2): purpose-made 10-20 L stackable jugs, 200 L drums with pump and bung wrench, or factory-sealed bottled water.
- Never reuse milk jugs (protein residue breeds bacteria and the plastic degrades). Old soda bottles washed with a bleach rinse are acceptable.
- Store cool and dark; sunlight grows algae in clear containers. Off concrete floors on wood slats (chemicals can leach through plastic from concrete).
- Tap water from a treated municipal supply stores as-is; rotate yearly. For well water, add 2 drops of unscented 5-6% bleach per litre when filling.
- Emergency last-minute capture: fill bathtubs (a tub liner like a WaterBOB holds ~350 L clean), sinks, pots, and washing machines the moment trouble is announced. Your hot-water tank holds 100-300 L of drinkable water (turn off power/gas to it, let it cool, drain from the bottom valve) and toilet tanks (not bowls) hold a few litres of tap water if no chemical pucks are used.
Treatment methods, ranked by what they kill
| Method | Bacteria | Protozoa (Giardia/Crypto) | Viruses | Notes |
|---|---|---|---|---|
| Rolling boil 1 min (3 min above 2,000 m) | yes | yes | yes | Gold standard; costs fuel |
| Hollow-fiber filter (0.1 micron, e.g. Sawyer-style) | yes | yes | NO | Fast, cheap per litre; protect from freezing |
| Purifier bottle (filter + ion/adsorption media) | yes | yes | yes | Cartridge lifespan limited |
| Unscented bleach 5-6%: 2 drops/L clear, 4 drops/L cloudy, wait 30-60 min | yes | partial (NOT Crypto) | yes | Bleach loses potency ~1 year after opening |
| Chlorine dioxide tablets | yes | yes (4 h wait for Crypto) | yes | Best chemical option; long shelf life |
| UV pen / SODIS (clear PET bottle, 6 h full sun) | yes | yes | yes | Clear water only; UV pens need batteries |
To purify cloudy, muddy, or dirty water from a river, lake, stream, or puddle: pre-filter first through a tightly woven cloth, coffee filter, or a Millbank bag (a canvas drip bag that removes sediment), or let it settle and decant. Sediment shelters microbes from chemicals and clogs filters.
Practical toolkit
A resilient household covers three layers: a gravity or squeeze hollow-fiber filter for volume, chlorine dioxide tablets as compact backup, and the knowledge + fuel to boil. Add a dedicated "dirty" and "clean" bucket pair to avoid cross-contamination, and mark them permanently.
Rain and wild sources
Rain catchment: a clean tarp or metal roof section feeding a barrel yields about 1 litre per square metre per millimetre of rain — a 20 m² roof in a 10 mm shower collects ~200 L. First-flush the initial runoff (it carries roof grime and bird droppings) and still treat before drinking. Wild sources: prefer moving water, collect from the surface (not stirred-up bottom), upstream of trails, livestock, and settlements. Never drink untreated surface water no matter how clear — Giardia is invisible. Salt water and urine are never drinkable and dehydrate you further; distillation is the only way to reclaim them.
Winter and hot climates
Freezing destroys hollow-fiber filters (cracked fibers pass microbes with no visible damage) — sleep with the filter in your jacket or switch to boiling and chemicals in winter. Melt snow with starter liquid in the pot; ice yields more water per volume than snow. In heat, ration sweat, not water: rest in shade through midday, work at dawn and dusk, and drink what you have — people have died of dehydration with water still in their canteens.