# 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.