Outbreak of Giardiasis Associated with Drinking Surface Water Along a Hiking Trail [Aquamira]

I carry 2 water treatment methods:

1. Steripen adventurer-> For fast treatment of bike bottle water (electrolyte drink bottle)

2. Katadyn Micropur chlorine dioxide tablets-> For OVERNIGHT hydration bag water treatment

3. FULL boil of untreated cooking water-> I use boiling only for cooking and cleanup water, including face wash or PTA "bath".

So far in 7 years this methods has proven very effective, including taking water over 4 days from a beaver dam in the Ruby Mountains of northern Nevada.

I believe the 4 hour treatment time is for Crypto (not common in the US I understand) and the worst water conditions (cold, dirty). I recall reading that Giardia in clear water needs at most 30 mins for cold water, less time in warmer water. There's an EPA document that covers all this, including dose-time relationships, don't have a ref at the moment…