To understand differences in water taste and quality, it’s helpful to understand the contrasting treatment regimens mains water and rainwater undergo.
In Australia, mains water treatment typically involves different forms of filtration and the addition of various chemicals, disinfectants and fluoride. Occasionally, UV disinfection is used in place of chemical disinfection. In areas with “harder” water, desalination is also used.
In contrast, drinking water harvested using a well-designed Rain Harvesting system passes through various filters before receiving UV treatment to kill any bacteria. Contaminant-laden water from the first “flush” of rainfall is diverted to reduce treatment requirements.
Unsurprisingly, these different treatment processes result in different tasting water.
Many people who prefer rainwater feel that the taste is “cleaner”, “purer” or even “sweeter”. It’s certainly much “softer” than desalinated “hard” water, and the taste is not altered by chemicals, disinfectants or fluoride.
While mains water treatment delivers water that’s fit for human consumption, many people see rainwater as a higher quality alternative because no additives are used to treat it.
Several public health authorities acknowledge that when rainwater comes from a well-maintained Rain Harvesting system – and it is clear and has little taste or odour – it’s also of a quality that is fit to drink.