Field KitL1-WAT-03 — Backup water treatment
“A second treatment method independent of the primary filter — chemical tablets, or the ability to boil.”
L1-WAT-03 requires a treatment method independent of the primary filter. Every filter on this page fails in a different way — freezing, clogging, cracking — and the redundancy clause exists precisely because those failures happen on the coldest, wettest days. Tablets are the standard answer for winter sessions where a hollow-fibre filter is a liability.
Same clause, different answers
Katadyn
A 0.1-micron hollow-fibre filter in a collapsible flask. Fast flow, field-cleanable by shaking, and light enough that people actually carry it.
L1-WAT-02 asks for a filtration method rated to 0.1 micron or finer that a student can clear in the field without tools. The BeFree meets both and its flow rate is high enough that students keep using it instead of quietly drinking untreated water, which is the real failure mode.