askvity

Contaminants in Rainwater

Published in Water Safety 3 mins read

Is Rainwater Drinkable?

No, rainwater is generally not safe to drink without proper treatment. While seemingly pure, rainwater can contain various contaminants that pose health risks.

Rainwater, while initially pure as it falls from the sky, becomes contaminated as it travels through the atmosphere and interacts with various surfaces. These contaminants include:

  • Bacteria and Viruses: These microorganisms can originate from animal waste, decaying organic matter, and airborne pollutants. They can cause various illnesses.
  • Chemicals: Industrial pollutants, agricultural runoff, and air pollution can introduce harmful chemicals into rainwater. Examples include forever chemicals (PFAS), which are persistent and potentially toxic.
  • Pollutants: Airborne particles, dust, and other pollutants can dissolve in rainwater, impacting its quality and safety.

Several sources confirm that rainwater isn't safe for consumption without treatment. The CDC explicitly states, "Rainwater is not necessarily safe to drink without first removing germs and chemicals from it."1 Studies show that even remote areas now exhibit unsafe levels of contaminants such as PFAS in rainwater. [2, 3](#ref2, #ref3) One study even suggests that "rainwater is no longer safe to drink anywhere on Earth." 4

Making Rainwater Safe to Drink

To make rainwater safe for drinking, several treatment methods are necessary:

  1. Collection: Using a clean collection system is crucial to minimize initial contamination. Roof surfaces should be clean, and the collection tank needs regular maintenance.
  2. Filtration: Filters remove solid particles, larger microorganisms, and some chemicals. Multiple filtration stages may be required for optimal results.
  3. Disinfection: Disinfection methods, such as boiling or using UV sterilization, kill remaining bacteria and viruses.

Conclusion

While rainwater might appear clean, it's crucial to understand that it's not safe for consumption without proper treatment to remove contaminants. Always treat rainwater before drinking, cooking, or bathing with it.


1 CDC: Collecting Rainwater and Your Health: An Overview | Drinking Water. https://www.cdc.gov/drinking-water/about/collecting-rainwater-and-your-health-an-overview.html


2 Popular Mechanics: Rainwater Is No Longer Safe to Drink, Study Says. https://www.popularmechanics.com/science/a40859859/rainwater-not-safe-to-drink/


3 CNET: I've Been Drinking Rainwater the Past 2 Years. Is It Time To Stop? https://www.cnet.com/science/ive-been-drinking-rainwater-the-past-2-years-is-it-time-to-stop/


4 Reddit: Rainwater is no longer safe to drink anywhere on Earth, scientists say. https://www.reddit.com/r/OffGrid/comments/wk1bwe/rainwater_is_no_longer_safe_to_drink_anywhere_on/

Related Articles