How safe is rain water to drink?
Rain water is the only water we have. By definition, it’s distilled water. Even acid rain is minimally harmful for human drinking. The only real risk is contamination is collection, transport, and storage. The common solution for a rooftop collector is diverting the flow to a drain for the first few minutes of rain, so dust is washed away before collection. Store in a closed cistern to keep out sunlight and animals. If you have a particular problem with particulates that don’t settle out in the cistern, add a simple line filter.
