FIELD NOTE 02 / Stay safe / First 72 hours
Water: the clear stuff can still betray you
Store a reserve, distinguish germ treatment from chemical contamination, and keep safe water safe after treatment.
Your objective
Identify a safe water source and keep a dated record of its storage or treatment.
Gather these
- Unopened bottled water if available
- Food-grade containers with lids
- Labels and pencil
- A safe way to boil water if needed
The procedure
Build a reserve
CDC recommends at least one US gallon (about 3.8 litres) per person per day for three days; aim for two weeks if feasible. Heat, illness, pregnancy, and pets can increase needs. This household reserve is not a complete community water-service standard.
Check the source
Use unopened commercially bottled water when possible. Follow local water advisories. Water containing fuel, toxic chemicals, or radioactive material cannot be made safe by boiling or disinfecting; use another safe source. Clear appearance and pleasant taste do not establish safety.
Treat germs when appropriate
For water without suspected chemical or radioactive contamination, filter cloudy water through a clean cloth or let it settle and draw off the clear water. Bring it to a rolling boil for one minute; above 6,500 feet (about 1,981 metres), boil for three minutes. Cool before use.
Protect the result
Store treated water in clean, sanitized containers with tight lids. Do not reuse containers that held toxic chemicals. Label the source and date. Keep stored water away from sunlight and chemicals; replace home-filled reserves every six months. Follow commercial water expiry information.
Keep separate records
Mark containers clearly as drinking water or non-drinking water. Record how much remains and who will arrange the next safe supply. If boiling is unavailable, consult the CDC source for disinfectant-specific instructions; do not improvise concentration or dosage.
Stop and get help when…
- Suspected chemical, fuel, or radioactive contamination: find a different safe source.
- A cloth removes particles; it does not disinfect water. An unknown filter does not guarantee pathogen removal.
A small, safe practice run
Calculate your household's three-day reserve and label one food-grade container. Record any practical gap without buying beyond your means.
Your field worksheet
Copy these prompts onto paper. Keep personal information private.
- People / days / planned litres or US gallons:
- Source / advisory / date:
- Treatment method / elevation if boiling:
- Safe volume remaining / next supply:
Sources and limits
Sources checked . The sources support the safety and reference facts; the worksheet and drill are Oikos planning suggestions.
Regional examples need local adaptation. For specialized treatment, building work, waste systems, or food processing, use qualified help and complete technical references.
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