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Water

5 min read

Part of Phase 0: First 72 Hours

Water Purification is the overview for 25 of this hub’s children, and its own prerequisite field is empty — nothing in Phase 0 needs to happen before this, which matches the domain’s own framing: locating, lifting, storing, and purifying water happens before anything else gets built.

Water Finding, Source Risk Rating, Surface Sources, Ground Sources, Spring Location, River Assessment, and Water Testing cover locating and judging a source before committing to it. Three days without water is roughly the survival limit, and finding it sooner is less about luck than reading where the landscape collects and channels it. A five-level risk scale runs from a protected well needing only filtration to industrial runoff boiling can’t fix, starting with a 200-meter upstream survey, and no field method detects viruses or dissolved chemicals, but a five-sense check and a sediment test still rank which sources are safer to drink. Spring water, filtered through soil and rock for months or years, emerges cleaner than any surface stream, while digging a well takes days and surface water is the fastest path to hydration at the cost of wider contamination risk.

Rain Harvesting, Catchment Systems, Atmospheric Sources, Well Digging, and Well Lining cover actually getting water once a source or method is chosen. Ten square meters of roof catching one 25 mm rainfall yields 250 liters, enough for weeks, provided a first-flush diverter discards the dirty runoff first, and doubling a catchment doubles its yield, with metal or plastic roofs running 90-95% efficient. A ground solar still yields only 0.5-1.5 liters a day even in good conditions, which is why dew, fog, and transpiration call for building three to five at once. Digging a one-meter test pit first confirms a well site works before the real shaft starts, and lining it as you descend is what prevents the cave-ins that kill most well diggers — dry-stacked stone needs no mortar and lasts twenty years or more.

Water Purification, Boiling Purification, Rolling Boil Method, SODIS Method, and Solar Disinfection cover treating water with heat or sun. A full minute at a rolling boil below 2,000 meters, three above it, is the gold standard, because heat kills pathogens by unraveling the proteins every organism depends on. SODIS needs a clear PET bottle, shaken 20-30 seconds to oxygenate and laid flat in sun, disinfecting by UV alone in 6 hours, or 2 overcast days — a method the WHO endorses and millions already use daily, speeding up once the water itself reaches around 50°C.

Filtration Methods, Sand Filtration, Ceramic Filtration, Charcoal Filtration, Chemical Treatment, Chlorine Sources, and Filter Maintenance cover filtering and dosing. Giardia and Cryptosporidium cysts resist chemical disinfection but get trapped by a good filter, treated here as the first barrier, not the only one. Coarse 0.5-1 mm sand removes sediment fast; a slow filter’s fine 0.15-0.35 mm bed grows a bacteria-removing biofilm instead, and scraping away only the top 1-2 cm once flow drops removes the clog while keeping that biofilm alive. A ceramic filter’s pores come from burnout material, roughly half the clay mix by volume, fired at 850-1,000°C, and a charcoal filter strips chemicals, taste, and turbidity but not bacteria, so it has to be paired with boiling. Chlorine stays the most practical chemical disinfectant after collapse, and household bleach at two drops per liter with a 30-minute wait is the simplest of the three chemical options.

Water Storage and Contamination Prevention close the loop: purified water can recontaminate three ways — bacterial regrowth, insects and dust, or leaching from the wrong container — and the thirty seconds right after treatment are the most dangerous moment of all, when a dirty rim or an unwashed hand can undo the entire process.

Finding and Assessing a Source

Judging where water is, how much, and whether it’s safe before committing to it.

Collecting Water

Rain, dew, and the wells that reach what’s already underground.

Treating Water: Heat and Sun

The gold-standard boil, and the no-fire sun-based alternatives that reach the same result slower.

Treating Water: Filtering and Chemicals

What a filter catches that chemicals can’t, and what chemicals catch that a filter can’t.

Storing and Protecting Purified Water

Keeping treated water safe in the thirty seconds after treatment, and for as long after that as it’s stored.

28 items under this folder.