Water Purification
Waterborne illness will ruin your trip or worse. Never drink untreated wild water in the UK — even clear-looking streams can contain giardia, cryptosporidium, and agricultural run-off. Multiple methods, carried together, give redundancy.
Professional instructor covers all methods with UK-relevant advice on water sources.
Boiling (1 minute at rolling boil) is the most reliable method. It kills everything. If you can make fire, you can make safe water.
A Sawyer Squeeze filter (about £30) filters down to 0.1 micron — removes bacteria and protozoa. Lightweight and field-serviceable. One of the best pieces of outdoor kit you can buy.
Purification tablets (chlorine dioxide, e.g. Aquamira or Katadyn Micropur) handle viruses too, but taste worse and take 30 minutes.
Always filter BEFORE purifying for best results. Pre-filter through a bandana if the water is visibly murky.
ASSESS the source: flowing water is better than stagnant. Avoid water downstream of farms or settlements
PRE-FILTER: If water is murky, filter through a bandana, t-shirt, or coffee filter to remove sediment
METHOD 1 — BOILING: Bring to a rolling boil for 1 minute (3 minutes above 2000m). Most reliable
METHOD 2 — FILTER: Use a Sawyer Squeeze, LifeStraw, or similar pump/gravity filter
METHOD 3 — CHEMICAL: Chlorine dioxide tablets. Follow packet instructions (usually 30 min wait)
METHOD 4 — UV: SteriPEN or similar UV purifier. Fast (90 seconds) but battery-dependent
For maximum safety: filter THEN chemical treat — covers bacteria, protozoa, AND viruses
Carry water containers: a Nalgene bottle or collapsible Platypus bag
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