SaWa Bag
SaWa Bag's Usability and Efficacy
SaWa Bag Feedback
User and Partner feedbacks are methodically collected throughout all SaWa Projects and National Programs.
The high scores, multiple endorsements, and strong partnerships with Governments and NGOs underline the need for SaWa’s efficacy in providing safe drinking water to people in low-income communities.
“SaWa Bag is especially good as it provides a closed loop solution that enables water purification for the individual family, while providing safe storage, and easy dispensing, ensuring no recontamination and only safe water.
– Godfrey Peterson Baguma UNHCR WASH Officer, Kyangwali Refugee Settleme
SaWa Bag Technology
SaWa Bag’s purification technique is based on the 40 year old Solar Water Disinfection (SODIS) process by PET bottles, which has been endorsed by the World Health Organisation (WHO) as a safe way to purify water. It works by harnessing UVA and UVB rays as well as heat from the sun.
The combination of these three processes kill the organic pathogens of concern present in water. More specifically, the UVA forms reactive oxygen species (ROS) in the water which play a critical role in inactivating the microorganisms. UVB directly damages the organism’s DNA and RNA. The heat initiates a heat pasteurization that works with the UV processes to accelerate the entire disinfection process.
SaWa Bag further improves the purification process by using a specialised plastic foil and construction that greatly increases the solar penetration and makes the process faster, killing a wider range of bacteria, viruses, and protozoa to a performance of 99.9%11. The model illustrates the sun emitting the UV rays that reach the bag, which initialize the SaWa product’s purification process.
SaWa’s increased UV Penetration
The graph below illustrates the results of UV measurements of SaWa Bag and a normal PET water bottle.
The significant difference is the instant onset of increased UVB (lower wavelength) penetration for the SaWa Bag, as this is the radiation that will purify the water faster.
SaWa’s Construction
SaWa Bag is constructed to hold 4 litres of water. Filled with water, the bag will form 3 cavities that ensure a rigid product and optimal solar exposure. SaWa Bag weighs 100g and takes up little space, making it easy to transport. SaWa Bag’s closed eco-system storage prevents the cleaned, safe drinking water to become recontaminated.
Certifications
Global Certification
The performance efficacy for SaWa Bag has been assessed according to international standards set by the World Health Organization (WHO) and U.S. Environmental Protection Agency (US EPA) for removing three different classes of microorganisms, i.e., bacteria, virus, and protozoa in drinking water.
SaWa Bag is CE marked and conforms with the provisions of the Machinery Directive 2006/42/EC under EEA legislation.
Local Verification
SaWa Bag’s performance efficacy has been rigorously tested during its design and development phases. Furthermore, SaWa Bag has been tested and verified by government-approved laboratories in the countries with SaWa Projects and SaWa National Programs.
Dependencies for SaWa Bag
The water is biologically contaminated.
The water is consumed within 3 days of solar exposure.
The water has a turbidity of less than 30 NTU (if SaWa logo can be seen through the lid with water in it, cleaning can proceed).
The water is exposed to the full recommended consecutive period of sunlight.
The water is not recontaminated by, for example, introducing it to a contaminated container.
SaWa Bag is placed facing the sun with the transparent side up.