The biosand water filter is a proven and highly effective clean water filter that works very well, particularly in the rural and underserved communities PWW serves, removing up to 99% of water-borne, disease-causing pathogens (read more about the filter here). However, recontamination of the stored water that has come out of the filter is possible. For this reason, PWW’s Water Quality team in Haiti is conducting tests to identify feasible solutions that support comprehensive disinfection of stored filtered water in family homes to protect it against potential, unintended recontamination.
During filter installation, families receive training about dispensing water into the top of the filter daily, collecting filtered water in a bucket with a lid, and applying chlorine tablets to the filtered water to reduce the risk of recontamination. Follow-up testing has revealed that some families do not fully comply with this protocol, in particular, the regular use of chlorine tablets. There are a variety of reasons for the non use of the chlorine tablets, including: families lacking funds, lack of availability of the tablets, and undesirable taste to name a few.
In an effort to better understand and resolve the challenges, PWW’s Haiti team is conducting a experimental study that encompasses a community survey, laboratory experimentation for possible alternative disinfection solutions, and field-testing with a focus on the initial 2-week period of filter activation.
As part of this study, PWW seeks to understand the effectiveness of a new product, MadiDrop, as a potential replacement to chlorine tablets, as well as to gauge user acceptance.
MadiDrop is a product developed and produced by US-based company, MadiDrop PBC. A ceramic disc, approximately the size of a bar of soap, the MadiDrop is infused with microscopic silver clusters (colloidal silver) and, when submerged in water, it slowly releases silver ions. The silver ions kill most pathogens in the water including E. coli, Vibrio cholera, Salmonella, and Shigella. Additionally, viruses like poliovirus and norovirus, as well as the protozoa Cryptosporidium parvum and Giardia lamblia, are susceptible to inactivation by the silver. Once submerged, there are no further steps to using the tablet, which will continue to release ions for at least six months.
To assist with this research project, the PWW Water Quality team has enlisted the help of Rachel Gray, a volunteer in Haiti with a background in environmental water quality. Below, Rachel shares about her experience in Haiti thus far:
By Rachel Gray, PWW Volunteer, Haiti
In August 2017, I joined the Pure Water for the World team in Haiti as a volunteer, making the perilous journey all the way from Sydney, Australia to the Caribbean. Despite noticing a distinct lack of hammocks, I have enjoyed my time here thus far, contributing to the design and implementation of an experiment within the walls of PWW. With a background in environmental water quality, I have much to learn about water in the context of drinking water in a developing world.
The MadiDrop experiment has kicked off without a hitch (knock on wood) aiming to determine the practicality and community acceptance of the newly emerging technology as a disinfectant and safe storage solution for filtered water.
The study also has a field component and field survey, both of which will inform PWW about user compliance with methods for correct chlorine use, as well as community acceptance and compliance with methods for MadiDrop use. Results are expected to inform training and future project implementations.
I feel very privileged to have this opportunity to contribute to the fantastic work that Pure Water for the World is doing. Haiti has really blown me away (more that Irma almost did) with the rich culture and unique lifestyle.
I look forward to seeing how my work here will positively influence the future of Pure Water for the World and the families they serve.