Purify Water in an Emergency

Key takeaways

• Boiling is the most reliable method — a rolling boil for one minute.
• Unscented bleach works when boiling isn't possible.
• Filter cloudy water first so treatment can work.

Step-by-step

1. Pre-filter. Pour cloudy water through a clean cloth or coffee filter to remove debris.
2. Boil. Bring to a rolling boil for at least one minute (three minutes above 2,000 m), then let cool.
3. Or chemically treat. Add 2 drops of unscented household bleach per litre, stir, and wait 30 minutes. A slight chlorine smell is normal.
4. Store treated water. Keep it covered in a clean container and use within a few days.

• Cloth or filter for pre-filtering
• Pot and heat source for boiling
• Unscented bleach + a dropper
• Clean covered container for output

Next guides to read

• Store Water Safely at Home →
• Collect Rainwater Responsibly →