Water purification is a critical aspect of preparedness for anyone as access to clean, safe drinking water is essential for survival. In a disaster or off-grid scenario, municipal water systems might be compromised, making independent water purification skills and tools invaluable.
Here’s a breakdown of water purification for preppers, covering methods, considerations and common tools:
Why Water Purification is Essential for Preppers:
- Survival: The human body can only go a few days without water.
- Health: Contaminated water can cause severe illnesses (cholera, giardia, cryptosporidiosis, E. coli, etc.) that can incapacitate or even be fatal, especially in situations where medical help is unavailable.
- Hygiene: Clean water is also needed for basic hygiene, cooking and sanitation.
Potential Water Sources in an Emergency:
Before purifying, you need a source. Common emergency sources include:
- Stored Water: Commercially bottled water (with varying shelf lives based on container type), or water stored in food-grade barrels or containers.
- Rainwater: Can be collected from roofs or tarps.
- Natural Sources: Rivers, streams, lakes, ponds, springs.
- Household Sources: Water heater tank, toilet tank (NOT the bowl), melted ice.
- Less Ideal Sources (Use with extreme caution and only after purification): Puddles, stagnant water.
Primary Water Purification Methods:
There are several effective methods, each with pros and cons:
1. Boiling: Heating water to a rolling boil for at least 1 minute (3 minutes at altitudes above 6,562 feet) effectively kills most bacteria, viruses, and protozoa.
Pros: Highly effective against biological contaminants, simple, doesn’t require special equipment beyond a heat source and a pot.
Cons: Doesn’t remove chemical contaminants, heavy metals, or sediment. Requires fuel. Water can taste “flat” afterward (can be improved by aeration).
2. Filtration (Physical Removal): Water is passed through a physical barrier with pores small enough to trap contaminants.
Types:
- Ceramic Filters: Durable and effective against bacteria and protozoa. Some are impregnated with silver to prevent bacterial growth.
- Hollow Fiber Filters: Use bundles of microscopic tubes with tiny pores to filter out bacteria, protozoa, and microplastics. Examples include LifeStraw, Sawyer Squeeze/Mini, and Katadyn filters.
- Activated Carbon Filters: Excellent for removing odors, tastes, chlorine, and some chemicals. Often used in conjunction with other filter types.
Pros: Removes sediment, visible particles, and often improves taste. Portable filters are great for individual use or small groups.
Cons: Most filters alone do not remove viruses (unless they are “purifiers” designed for viruses, typically with very fine pore sizes like 0.02 microns or through chemical/UV post-treatment). Filters can clog and require cleaning or replacement.
3. Chemical Treatment: Chemicals are added to water to kill microorganisms.
Types:
- Chlorine Dioxide Tablets/Drops (e.g., AquaMira, Katadyn Micropur Forte): Generally considered more effective than iodine, kills bacteria, viruses and protozoa (including Giardia and Cryptosporidium, though some require longer contact times).
- Iodine Tablets (e.g., Potable Aqua): Effective against bacteria and viruses, but less so against some protozoa like Cryptosporidium. Can leave an unpleasant taste and may not be suitable for pregnant women or those with thyroid conditions.
- Unscented Household Bleach (Sodium Hypochlorite): In a pinch, regular unscented bleach (containing 5.25% to 8.25% sodium hypochlorite) can be used. Use a very small amount (e.g., 2 drops per liter for 5.25% bleach, or 8 drops per gallon for 5.25% bleach) and wait at least 30 minutes. Always research proper ratios.
Pros: Lightweight, compact, easy to use, effective against a broad range of pathogens (especially chlorine dioxide).
Cons: Can affect taste. Requires waiting time. May not kill all pathogens (especially with iodine against Cryptosporidium). Doesn’t remove sediment or chemicals. Bleach should be unscented and fresh.
4. UV (Ultraviolet) Light: UV light damages the DNA of microorganisms, preventing them from reproducing and rendering them harmless.
Devices: SteriPen is a popular example. Some gravity filters also integrate UV light.
Pros: No chemicals, no taste alteration, effective against bacteria, viruses, and protozoa. Relatively fast.
Cons: Requires batteries or a power source. Water must be clear for UV light to be effective (sediment will block the UV rays). Doesn’t remove sediment or chemicals.
5. Distillation: Water is boiled and the steam is collected and condensed back into liquid form, leaving contaminants behind.
Pros: Highly effective, removes virtually all contaminants, including bacteria, viruses, protozoa, heavy metals, salts, and most chemicals.
Cons: Energy-intensive, slow process, impractical for large volumes. Can be a complex setup.
Important Considerations for Preppers:
- Pre-filtration: Regardless of the purification method, always pre-filter turbid (cloudy) water through a cloth, coffee filter, or even a DIY sediment filter (layers of sand, gravel, charcoal, and cloth in a cut-open plastic bottle) to remove larger particles. This improves effectiveness and extends the life of other purification methods.
- Redundancy: Don’t rely on just one method. Have multiple options (e.g., a portable filter, purification tablets, and the ability to boil).
- Volume: Consider how much water you’ll need. Individual straw filters are great for personal use, but gravity filters or larger pump filters are better for groups.
- Storage: Purifying water is one thing, but storing it safely is another. Use food-grade containers and store them in a cool, dark place.
- Maintenance: Know how to clean and maintain your filters and other purification equipment.
- Practice: Practice using your water purification methods before an emergency strikes.
- Chemicals/Taste: Some methods can leave an aftertaste. Consider bringing flavoring packets if this is a concern.
- Beyond Pathogens: While most methods focus on biological contaminants, chemical spills or heavy metal contamination require more advanced filtration or distillation.
Popular Products & Systems for Preppers:
- Personal Straw Filters: LifeStraw, Sawyer Mini.
- Squeeze Filters: Sawyer Squeeze.
- Pump Filters: Katadyn Hiker Pro, MSR MiniWorks EX.
- Gravity Filters: Platypus GravityWorks, Sawyer Gravity Systems, LifeStraw Peak Gravity.
- Bottle Filters: Grayl GeoPress.
- Tablets: Potable Aqua, Katadyn Micropur Forte, AquaMira.
- UV Purifiers: SteriPen.
- Larger Home Systems: Berkey-style gravity filters (often ceramic/carbon).
For preppers, a multi-faceted approach to water purification combining storage, filtration, and disinfection methods, is key to ensuring a reliable supply of safe drinking water in any scenario.