The following short notice by Mark Jenkins appeared in NG (Apr 2010) concerning an easily, low-tech water treatment procedure:
“Retrieve a discarded water bottle. Tear off the label and fill with any water that’s not too murky from a creek, standpipe, or puddle. Place the bottle on a piece of metal in full sun. In six hours the UVA radiation will kill viruses, bacteria, and parasites in the water, making it safe to drink.
SODIS, the acronym for this Swiss-pioneered water-disinfection program, is now being used all over the world to provide drinking water for some 4 million people. “It’s simple, it’s free, and it’s effective,” says Ibelatha Mhelela, principal of the Ndolela Primary School in Tanzania. In 2006 her school started using SODIS to disinfect its contaminated tap water, placing bottles on the building’s corrugated metal roof. The result? Absenteeism due to diarhea dropped considerably, and examination scores soared. “Before we started SODIS, only 10 to 15 perceont of the children passed the national 6th-grade exams,” says Mhelela. “Now 90 to 95 percent of the students pass.”"
When I read this, I automatically shriveled up my nose and went, “ew”. It sounds too good to be true. It must be psycological, but I would have a real hard time drinking bottled water that I knew came from a llama’s (or whatever–fill in the blank) watering trough. Then again, that shows my spoiled brat white girl mentality. Other people in the world, and organizations who are fighting to make a difference, must truly appreciate what appears to be a fairly simple solution to a huge problem.
Continuous, strong sunlight does all the hard work of SODIS. But the following tips help the process along: (1) Use bottles of clear PET plastic rather than glass. Studies show water from sun-warmed PET is safe to drink; (2) Do not disturb bottles while they sit in the sun; and (3) store water in bottle to prevent recontamination.
A somewhat related effort is being proposed by students at BYU:
Three graduate students at Brigham Young University want to bring another option (beside expense bottled water) to Kenyans: plastic pouches of clean water than everyone can afford. They’ve seen it in action in western Africa, and are sure the social venture can be equally successful on the continent’s untested eastern coast.
They’re calling the project Marere Pure Water — “marere” means fountain in Swahili, which is spoken alongside English in Kenya. Marere Springs is also the anme of the Mombasa, Kenya, natural municipal water source into which they’ll be tapping for their supply.
Decent water bottles in Kenya currently go for about 20 shillings, or 25 cents, while the top-shelf bottles sell for a buck apiece. Marere will sell 17-ouce polyethylene bags for 10 shillings, or 12 cents, each. The simple sachet design–the corner of which is bit into for a drink is exactly what Kenyans need, and nothing more.
In Ghana and Cameroon, this is a proven business model, according to Marere co-founder and BYU MBA student Zac Clarke, who witnessed the success firsthand while working with the Peace Corp in Cameroon.