HOW TO DRINK ANY WATER

IN THE AFTERMATH of natural disasters, contaminated drinking water is one of the biggest dangers. “There’s a ton of pathogens in water that cause moderate to life-threatening gastroenteritis,” says Bruce Gordon, co-ordinator of water, sanitation, hygiene and health at the World Health Organisation. Areas with on-site sanitation, such as septic tanks, are most likely to put faecal matter into circulation in post-hurricane or -tsunami floods. But the breakdown of infrastructure is also a threat. An earthquake or tornado can destroy a pipe system and cut off delivery altogether, and even minor cracks can allow in contaminants. When quality is in question, Gordon recommends filtration and then chlorine dioxide tablets. Microfilters are the easiest personal water treatments. Water passes through an ultra-thin membrane, the pores of which are small enough to keep out dirt, bacteria and protozoan cysts. Viruses are too small for most filters, says Gordon, but chlorine dioxide will knock them out. The filters we tested and picked are sturdy, portable and intuitive; as useful on long backpacking trips as they are after a hurricane hits.

KATADYN BE FREE SYSTEM

The Befree’s 0,1-micron (0,0001 mm) membrane catches all pathogens except viruses. Sans water, it’s a mere 50 g, and the bottle rolls up for compact storage between refills. katadyn.com

SAWYER ONE- GALLON GRAVITY FILTER

Hang the 3,5 litre bag and gravity forces the water down through tubing and the Sawyer MINI filter, rated to 0,1 microns. The MINI filter can also be removed and screwed onto a standardsize disposable water bottle. sawyer.com

MSR GUARDIAN

The Guardian’s 0,02-micron filter is among the only to block most viruses in addition to larger pathogens. The floating prefilter and hand pump let you move more water, faster. And the self-cleaning filter eliminates maintenance. msrgear.com