Have you ever wanted to drink rainwater? You imagine yourself running outside when it is raining, looking up with your arms stretched out, opening your mouth wide open and taking in that clean, fresh and cool rainwater! Whilst doing all this in slow motion – life is great!

Hold your horses, reality may not be as rosy as that. Generally rainwater is considered safe but there are some precautions that you need to consider just to be on the safe side. Remember, sustainability is not about saving water and then getting sick with E.Coli in the process.

So you read the previous article on How To Collect Rainwater The Simple And Professional Way and you started collecting rainwater. Good for you! Now you have used it to water the indoor plants, wash the porch and get your children to wash the car for you (Since they are on their school holidays and they need time away from their devices anyway!).

Now you are getting excited! There is all this rainwater and you start thinking of all the DIY projects that you can do around the house but the Wife quickly reminds you of all the other projects that you started and never finished. You give in this time (as with many other times before) but in your heart and your mind you know they are all going to be finished – it is just waiting for the right time.

Back to rainwater and how safe is it for drinking?

Riffat Shaheed and Wan Hanna Melini Wan Mohtar of Universiti Teknologi Malaysia ran a study in 2014 looking at the Potential Of Using Rainwater for Potable Purpose in Malaysia with Varying Antecedent Dry Intervals and the results were encouraging. In their conclusion, they said:

Analysis shows that with simple treatment and disinfection, utility of rainwater in Malaysia can be extended to potable uses from its current non-potable uses.

It is recommended to take the following 3 steps to ensure that the harvested rainwater is safe for potable use:

  1. Keep the piping system between the rainwater and treated water from the mains separate as you would not want to run the risk of contaminating the treated water from the mains
  2. Keep the rooftops, rain gutters, rainwater pipes, storage tank and any other parts in contact with the water clean from any mold, debris or any other possible contaminants
  3. Ensure that the first flush and main screen filters are in good working condition at all times
  4. Always treat rainwater first before using it for potable use. You will need to run it through several filters:
    • a fine fiber filter and carbon filter to remove very fine particles
    • a chemical or a UV filter to disinfect the water

Do note that this is just a general guideline, please do consult with the rainwater filtration experts for a proper and comprehensive solution such as DD Techniche Sdn Bhd.

Now we know that:

It is important to collect rainwater – Article 1

We can easily collect rainwater – Article 2

Using rainwater for potable use is also possible!

Next we will get into some technical details and simple calculations with the help of NAHRIM!