Chapter 6
Water: Purification Without a Filter
Printed in full here from the book.
Water Comes First
You can judge a blackwater source, clarify it, and produce safer drinking water with heat or sunlight when a filter is gone.
- Water Priority Bad water can take you out faster than hunger. Dehydration degrades judgment, strength, and body cooling, so make water a top priority after you reach a safe place.
- Blackwater Pathogens In blackwater, a pretty spring, a clear creek, or a fast run can still carry giardia, cryptosporidium, viruses, and other pathogens. Clear water is not proof of safety.
- Cleanest Source Choose the cleanest source you can reach. Flowing water, a spring, direct rain, and dew are better starting points than a stagnant pond or swamp. Avoid water with a dead animal, floating material, a strong odor, or a chemical sheen.
- Never Saltwater Never trust saltwater. Heat can control many disease organisms, but boiling does not remove heavy metals, salts, fuel, or most other chemicals. If the source may be chemically polluted, move to another source and follow local health guidance.
Check it. Pass: you can name the cleanest source and refuse saltwater.
Field check
- I choose the cleanest source I can reach.
- I avoid water with a dead animal, floating material, a strong odor, or a chemical sheen.
- I never trust saltwater.
- I treat water with tea color before drinking.
Safety. Clear water is not proof of safety.
Clarify Before Treatment
Clear is not clean. Treat every natural water source before drinking, and never expect boiling to remove chemicals.
- Settle Muddy Water Let muddy water settle before treatment. Pour the clearer water through a clean cloth, paper towel, or coffee filter. This removes grit and reduces cloudiness.
- Prefilter It does not make the water safe by itself. A gravel, sand, charcoal, and cloth column can clarify water, but it is still only a prefilter. Treat the clarified water with heat or another method made for drinking water.
- Keep Water Separate Keep raw water, dirty tools, and treated water separate. A metal pot is the best field answer. When metal is gone, a green leaf bowl, bamboo section, or hollow log can hold water while heated stones do the work.
- Sun Backups Sun methods are backups. A solar still can produce clean condensate from moist soil, plants, polluted water, or saltwater, but it takes time and energy and yields little. A clear bag around a leafy, non-toxic branch collects transpiration. Do not taste an unknown plant to make a bag still.
Check it. Pass: muddy water settles and passes through cloth.
Field check
- I let muddy water settle before treatment.
- I pour the clearer water through a clean cloth, paper towel, or coffee filter.
- I keep raw water, dirty tools, and treated water separate.
- I treat clarified water with heat or another method made for drinking water.
Safety. A gravel, sand, charcoal, and cloth column can clarify water, but it is still only a prefilter.
Repeatable Water Chain
The goal is a repeatable chain: choose the best source, clarify it, treat it, cool it, and store it covered.
- No Clever Trick The goal is not a clever trick. The goal is a repeatable chain: choose the best source, clarify it, treat it, cool it, and store it covered.
- Stop Chemical Water If the water smells like fuel or solvent, stop. Do not try to fix chemical contamination with boiling.
- Refuge Water Rule On the Okefenokee refuge, drinking or filtering swamp water is NOT recommended; bring all drinking and cooking water; one gallon per person per day is recommended.
You need: Tea Color Rule (Tea color from leaves and wood is normal in blackwater, but you must still treat it.)
Check it. Pass: you can state the chain from source to covered storage.
Field check
- I choose the best source.
- I clarify the water.
- I treat it and cool it covered.
- I store it covered.
- I bring all drinking and cooking water on the refuge.
Safety. If the water smells like fuel or solvent, stop.
Make the Safe Batch
Collect enough water for the whole task before you light a fire.
- Set Collection Point Collect enough water for the whole task before you light a fire. Set the collection point away from the fire site, latrine area, and animal traffic. A hot pot burns skin. Use a stable fire lay in an open place, never under or near a tarp or tent.
- Start Treatment Time When the water reaches a full rolling boil, start the treatment time. Keep that boil for at least one minute. Local health guidance can be stricter, so follow the local rule.
- Cool With Cover Cloudy water gets a cloth prefilter first. Heat the water in a metal container, then let it cool naturally with a cover. Pouring cooled water between clean containers can improve the flat taste.
- Finished Batch Do not add raw water to the treated container. Do not dip dirty hands, a used cup, or an unclean bandanna into the finished batch. Keep a second container for raw water if you have one.
Check it. Pass: the boil is full and timed, and raw water never touches the batch.
Field check
- I collect enough water for the whole task before I light a fire.
- I set the collection point away from the fire site, latrine area, and animal traffic.
- I keep the boil for at least one minute.
- I keep raw water out of the treated container.
Safety. A hot pot burns skin.
Rock Boiling Fallback
If you have no metal, rock boiling can work in a non-fireproof container.
- Choose Safe Stones If you have no metal, rock boiling can work in a non-fireproof container. Choose dry stones with no air pockets, and never use limestone, sandstone, or stones from the water. Heat them in the fire, move them with a stick, and lower them into the water.
- Keep Face Back Hot stones can crack or burst, so keep your face and hands back. Continue with fresh hot stones until the water reaches the required boil.
- Treat As Fallback This is slower and more dangerous than a metal pot. Treat it as a fallback, not a demonstration.
You need: No Safe Stones (If you cannot find safe stones, do not use this method.)
Check it. Pass: stones are dry with no air pockets, and your face stays back.
Field check
- I choose dry stones with no air pockets.
- I move them with a stick.
- I keep my face and hands back.
- I treat rock boiling as a fallback, not a demonstration.
Safety. Hot stones can crack or burst, so keep your face and hands back.
Solar Still Method
A solar still is a last-resort collector, not a replacement for a pot when fuel and a good source are available.
- Dig the Bowl Dig a bowl about 3 feet across and 24 inches deep in a sunny patch above the water table, place the cup in a center sump, cover the hole with clear plastic, seal the edges, and hang the center of the sheet over the cup. Condensation runs to the low point.
- Transpiration Principle A transpiration bag works on a different principle: leaves release moisture into the bag, where it condenses. The branch must be leafy and non-toxic.
- Clean Collection Both methods need a clean collection vessel and a plan for storage. A solar still can produce clean condensate from moist soil, plants, polluted water, or saltwater, but it takes time and energy and yields little.
You need: Do Not Taste Plants (Do not taste an unknown plant to make a bag still. If the water smells like fuel or solvent, stop.)
Check it. Pass: the bowl is about 3 feet across and 24 inches deep.
Field check
- I dig a bowl about 3 feet across and 24 inches deep.
- I place the cup in a center sump.
- I seal the edges.
- I keep a clean collection vessel and a plan for storage.
Safety. A solar still is a last-resort collector, not a replacement for a pot when fuel and a good source are available.
Clean Collection Vessel
Both methods need a clean collection vessel and a plan for storage.
- Clean Vessel Both methods need a clean collection vessel and a plan for storage. A transpiration bag works on a different principle: leaves release moisture into the bag, where it condenses.
- Leafy Branch The branch must be leafy and non-toxic. Do not taste an unknown plant to make a bag still.
- Store Covered The goal is a repeatable chain: choose the best source, clarify it, treat it, cool it, and store it covered. Both methods need a clean collection vessel and a plan for storage.
- Follow Local Rule Local health guidance can be stricter, so follow the local rule. A solar still is a last-resort collector, not a replacement for a pot when fuel and a good source are available.
Check it. Pass: the vessel is clean, the branch is identified, and the water is covered.
Field check
- I keep the branch leafy and non-toxic.
- I keep a clean collection vessel.
- I have a plan for storage.
- I follow the local rule.
Safety. The branch must be leafy and non-toxic.
What You Need
You can judge a blackwater source, clarify it, and produce safer drinking water with heat or sunlight when a filter is gone.
- Metal Canteen Metal canteen or pot with lid
- Clear Plastic Clear plastic sheet or clear bag
You need: Clean Cloth (Clean cloth)
Field check
- I have a metal canteen or pot with lid.
- I have a clear plastic sheet or clear bag.
- I have a clean cloth.
- I have a fire kit or safe heat source.
- I have clean covered containers.
Safety. Keep every stove and fire in an open area, never under or near a tarp or tent.
- Fire Kit Fire kit or safe heat source
- Covered Containers Clean covered containers
Field check
- I have a metal canteen or pot with lid.
- I have a clear plastic sheet or clear bag.
- I have a clean cloth.
- I have a fire kit or safe heat source.
- I have clean covered containers.
Safety. Keep every stove and fire in an open area, never under or near a tarp or tent.
Boiling in Metal
A metal pot is the best field answer.
- Choose Best Source Choose the best available flowing source, spring, rain, or dew, and avoid water with a strong odor, floating material, or a chemical sheen.
- Filter Into Pot Let cloudy water settle, then pour the clearer water through a clean cloth into a metal pot.
- Use Open Heat Place the pot on a stable fire or safe heat source in an open area away from any tarp or tent.
- Hold Full Boil Bring the water to a full rolling boil and hold it for at least 1 minute, following the local rule if it differs.
- Cool Covered Cover the pot, let the water cool naturally, and transfer it to a clean covered container without touching the treated water with dirty tools.
Check it. Pass when the water reached a full rolling boil for the correct locally applicable time, cooled covered, and entered a clean covered container. Fail if it was only steaming, if raw water touched the finished batch, or if chemical contamination was suspected.
Field check
- I let cloudy water settle.
- I place the pot on a stable fire or safe heat source.
- I hold the boil for at least 1 minute.
- I cool the water naturally with a cover.
- I transfer it to a clean covered container.
Safety. Boiling does not remove fuel, salt, heavy metals, or most chemicals.
Rock Boiling
If you have no metal, rock boiling can work in a non-fireproof container.
- Make Water Container Make a green-leaf bowl, bamboo section, or hollow log that holds water and sits away from the fire edge.
- Strain Muddy Water Strain muddy water through clean cloth before heating it in the improvised container.
- Heat Dry Stones Select dry stones with no air pockets, never limestone, sandstone, or stones from the water, and heat them in the fire with your face and hands clear.
- Move One Stone Move one hot stone at a time with a stick and lower it into the water without splashing yourself.
- Replace Cooling Stones Replace cooling stones until the water reaches a full rolling boil for the locally applicable treatment time, then cool it covered.
Check it. Pass when the container held water without leaking, the water reached a rolling boil, and the finished water cooled covered. Fail if a stone cracked near the face, the container touched flame, or the water never reached a rolling boil.
Field check
- I make a green-leaf bowl, bamboo section, or hollow log.
- I strain muddy water through clean cloth.
- I select dry stones with no air pockets.
- I keep my face and hands clear.
- I move one hot stone at a time with a stick.
Safety. Hot stones can burst.
Belowground Solar Still
A solar still is a last-resort collector, not a replacement for a pot when fuel and a good source are available.
- Dig Sunny Bowl Choose a sunny patch and dig a bowl about 3 feet across and 24 inches deep, checking first for roots, unstable soil, and flooding.
- Dig Center Sump Dig a center sump that lets the collection cup stand upright without touching the soil.
- Place Clean Cup Place the cup in the sump, add green vegetation if available, and keep polluted source water outside the collection cup.
- Seal Clear Plastic Lay clear plastic over the bowl, seal its edges with soil, and set a small stone over the cup so the sheet slopes to the center.
- Collect Condensate Collect the condensate without disturbing the sheet, then cover the cup and treat the water again if the collection surface or vessel was not clean.
Check it. Pass when the plastic is sealed, the low point sits directly over the cup, and condensate reaches the cup without touching soil. Fail when the plastic touches the sides, the cup is unstable, or the source water splashes into the cup.
Field check
- I dig a bowl about 3 feet across and 24 inches deep.
- I dig a center sump.
- I keep polluted source water outside the collection cup.
- I seal the edges with soil.
- I cover the cup.
Safety. Choose a sunny patch and dig a bowl about 3 feet across and 24 inches deep, checking first for roots, unstable soil, and flooding.
Transpiration Bag
A clear bag around a leafy, non-toxic branch collects transpiration.
- Select Safe Branch Select a healthy leafy branch from a plant you can identify as non-toxic, away from spray, dead animals, and foul water.
- Tie Clear Bag Tie a clear bag around the leafy branch so the seal is above the lowest point and the leaves have room inside.
- Set Lowest Corner Set the lowest corner toward a clean cup or place a clean cup under the bag’s low point.
- Prefilter Muddy Water For muddy source water, let sediment settle and run the clearer portion through gravel, sand, charcoal, and cloth only to remove sediment.
- Boil Before Drinking Boil all collected or prefiltered water before drinking unless an approved treatment label or local health authority gives a different instruction.
Check it. Pass when the bag is sealed around an identified non-toxic leafy branch and water collects without contact with soil. Fail when the plant is unknown, the bag leaks, or clarified water is treated as purified without boiling.
Field check
- I select a healthy leafy branch.
- I identify the plant as non-toxic.
- I tie a clear bag around the leafy branch.
- I place a clean cup under the bag’s low point.
- I boil all collected or prefiltered water before drinking.
Safety. Do not taste an unknown plant to make a bag still.
