No, chlorine is not naturally present in rainwater. Rainwater is considered pure and natural because it doesn't contain added chemicals or contaminants like chlorine, fluoride, and other substances often found in tap water. This makes it a popular choice for those sensitive to these additives.
However, it's crucial to understand the context. While rainwater itself is chlorine-free, chlorine can be added to rainwater harvesting systems for disinfection purposes. This is often done in rainwater storage tanks to prevent bacterial growth, particularly if the water is intended for consumption or other uses requiring sanitation. The addition of chlorine is not a natural occurrence, but rather a deliberate act of treatment.
Examples of Chlorine Use (Non-Natural):
- Rainwater Harvesting Systems: Chlorine bleach, often in diluted amounts, might be added to storage tanks to eliminate harmful bacteria. This is a common practice in off-grid living or situations where rainwater is the primary water source. See this article on using chlorine in rainwater storage tanks
- Water Treatment Plants: Some larger-scale rainwater collection systems used in municipalities may use chlorine for disinfection as part of a broader water treatment process. This is outside the scope of natural rainwater.
It is important to distinguish between the naturally occurring composition of rainwater and the potential for human intervention in the form of disinfection. Un-treated rainwater will not contain chlorine. Rainwater used for drinking or other purposes must be treated and disinfected to make it potable.
