Plastic bottles and lots of sun—these are all that poor people need to purify contaminated water, according to a nongovernment organization in Indonesia. By following a simple process called solar water disinfection, slum communities can have clean, inexpensive, drinking water within their reach. But why are some slum residents still reluctant?
Poor residents in Bintaro, South Jakarta know that the sun and plastic bottles are all that they need to make unsafe water potable. They simply clean used transparent plastic bottles, refill them with water from deep wells, screw the bottle caps back on, and leave them under the scorching rays of the sun for 6 hours—and they get water safe for drinking.
The process is known as solar water disinfection—using the sun’s natural radiation to kill a variety of water bacteria which cause common water-borne diseases such as diarrhea, typhoid, cholera, and dysentery.
“We don’t have to spend money anymore to have clean drinking water,” said Dewi, a 29-year-old housewife and mother of three. Dewi’s family is among the 52 poor households living near a dump site on Jalan Bintaro Permai in Pesanggrahan who were taught the process by Yayasan Emmanuel, a nongovernment organization in Bogor. They have been sterilizing water using this process for the past two months now.
“The solar water disinfection process is not complicated. One just has to make sure that the bottles are filled to the brim to keep air out, as air can deflect the sun’s ultraviolet rays and prevent them from killing bacteria in the water,” said Mindy Weimer, Yayasan Emmanuel’s Water Program director. “If the bottles are laid on a piece of black cloth, the water will absorb heat faster,” Weimer added. But Bintaro residents just place the bottles on the roofs of their shacks with much the same results.
“It’s like drinking bottled water,” said 40-year-old village head Mulyani, who was at first skeptical and scared to drink the water that she sterilized under the sun.
Dewi and her neighbors used to sterilize contaminated water by boiling it, spending Rp45,000 (US$5) a month on kerosene for her stove. This is a huge amount for Dewi whose husband earns only Rp10,000 (US$1) a day from foraging trash in the dumpsite.
Indonesia’s health ministry says more than 90 percent of the country’s population boil water everyday, but the ministry is against the practice as it causes air pollution. Zainal Nampira, head of the sub-division water sanitation directorate of the health ministry, said, “The smoke from burning kerosene or firewood causes eye irritation and lung problems.” Nampira also added that disease-causing organisms will not be killed if water is not boiled properly. To make it safe for drinking, water should be allowed to boil for one minute.
Data from the ministry shows that about 80% of Indonesia’s population gets water from contaminated sources, and that groundwater is contaminated by fecal coliform. Boiling was then the only option for Bintaro residents, until solar water disinfection was introduced.
Since she started using the process, Dewi has been able to save money on kerosene. From 15 liters of kerosene per month, Dewi now buys only 6 liters for cooking, saving Rp27,000 (US$3) monthly. The money she saves goes to the schooling of her 12-year-old daughter. Bintaro residents are also able to save money on medication, as their children no longer suffer from persistent diarrhea.
While Yayasan Emmanuel continues to introduce the process to other communities, people are still reluctant to use solar water disinfection for several reasons.
A very basic reason is the lack of plastic bottles, since they also sell them to earn money. Dewi, for example, only uses three large plastic bottles, but her family consumes about four bottles of water a day. “If we’re really thirsty, we just drink water straight from the well,” Dewi said.
Another reason is the long disinfection period. During sunny days, people have to wait for 6 hours for the water to be disinfected. However, if the weather is cloudy, they have to expose their plastic bottles to the sun’s rays for two days. “We cannot rely on the weather. Sometimes, it’s not sunny,” Syarief, another resident, lamented.
Yayasan Emmanuel public health engineer Arum Wulandari also warns, “Exposing water to solar radiation does not kill all kinds of bacteria.” She advises people using the solar water disinfection process to wash the plastic bottles before refilling them with water.
The organization also does not recommend water treated through solar disinfection to children below two years old and people with HIV/AIDS because they have weaker immune systems.
Although solar water disinfection is a cheap way of purifying water, few communities currently practice the process. Well-to-do Indonesians simply buy gallons of mineral water, which costs over a dollar per gallon—something that Dewi’s family could not afford. They just wait for used plastic bottles from rich people’s trash. Outside Jakarta, the process is used by some residents in earthquake-stricken Yogyakarta and in East Lombok province.
To promote its practice, the Yayasan Emmanuel distributes comic books on the solar water disinfection process to school children, particularly to those living in slum areas. Mita Sirait, the organization’s public health promoter, said, “We believe that children can influence their parents to treat water through solar disinfection.”