Sunny solutions by Zahra Ali

Guilty of overindulging in bottled water? You’re certainly not the only one. The number of “health-conscious” people in Pakistan, who carry their bottles of mineral water while rushing off to work, sauntering in parks and shopping at malls, is on the rise. Bottled water is now ubiquitous in Pakistan — not only is it on the checklist of essentials of most people; it’s also served during conferences and business meetings. And there are figures to prove its rampant consumption. The use of bottled water — typically considered as high quality and safe drinking H20  — is growing by 40 per cent each year. In the year 2000 alone, Pakistan experienced an astonishing 140 per cent growth in bottled water usage — the highest in Asia. It is estimated that the cost of mineral water for one person is roughly Rs1,400 per month — equivalent to Rs. 16,800 per annum. That is a lot of money for something that is our basic right: drinkable water!

The increasing acceptance of bottled water has obviously made consumption of tap water — generally associated with nasty stomach bugs — unthinkable in today’s age. But what if I told you that you can purify water, straight from the tap? You won’t even have to filter or boil it.  All you need are some empty PET (Polyethylene Terephthalate) bottles, clear tap water and some bright sunlight and you can start the solar water disinfection (SODIS) process at home! This process, developed by the University of Beirut in 1985, has been practiced in many countries and regions around the world, including Pakistan.


To purify your water by using sunlight, simply follow these steps:

Find PET bottles with a resin identification sign of 1. Your plastic water or juice bottles are safe to be reused for this project. The bottles must not contain more than 3 litres of water.

• Wash the bottles thoroughly with soup.

• Fill them with tap water. Make sure your tap water is visibly                                            clean. This method is not very effective for hard water.

• Put on the cap and place the bottles in full sunlight for at least 6 hours. If it’s cloudy, keep them out there for two days.

Your water, without any added chemicals, is now ready to drink!

Despite being the simplest way to purify your water, SODIS has a few disadvantages:

• The process will only be fully effective on sunny days

• It does not work on hard water (water with high mineral con  tent)

• It takes time and effort.

But look at the bright side (pun intended) of the entire procedure. It’s a natural, eco-friendly and healthy way of disinfecting your water and will allow you to save money in the long-term. And as far as the exertion required in disinfection is concerned, a light workout never harmed anyone!

So go ahead: make use of nature and purify your water the sunny way!

Published in The Express Tribune, Sunday Magazine, December 11th, 2011.

You Might Also Like

Leave a Reply