Thanks for the interest and for the questions. The question about filtration is a common one because the in-line "Filters" often discussed by traditional hydration pack companies are simply "bad taste" removers and not real filters. The reason for this is because it is very difficult to suck water through a real filter. The President of KATADYN filters was very encouraged to see the GEIGERRIG and our in-line filtration because KATADYN has worked on in-line filters for Hydration Packs, but has had limited traction in that area because of the limitations presented by having to suck the water through the tube and in-line filter. The GEIGERRIG in-line filter is a real filter. It removes 99.9% of Giardia, 99.9% of Crypto and 99.9% of bacteria. It is rated for 50 gallons of filtration. So... Yes, the GEIGERRIG in-line filter works in streams, rivers, ponds, lakes, etc.