Photography by Kerry-Ann Hamilton
The Howard University chapter of Engineers Without Borders has successfully installed four concrete biosand filters in Choimim, Kenya.
This rural farm community does not have running water and people often gather water from wells, rainwater harvesting and the river. Waterborne diseases such as cholera and typhoid are prevalent, mainly because of poor purification and sanitation. EWB-HU has conducted a series of trainings with community members to improve water treatment and storage.
Another solution for water purification is the biosand filter (BSF). The BSF is an adaptation of the traditional slow sand filter, which has been used for community water treatment for almost two hundred years. The biosand filter is smaller and adapted for intermittent use, making it suitable for households. The filter container can be made of concrete or plastic and is filled with layers of specially selected and prepared sand and gravel.
The EWB-HU Team worked with Isaac Soita, co-founder of Running Water International, to install the four biosand filters. The BSFs were placed in Siwo Dispensary, the Build the Village orphanage, and two homes. During the installation process, the EWB-HU team trained the recipients on proper use and maintenance. A team of community engineers also worked alongside EWB-HU to ensure knowledge transfer and sustainability.
The preparation of the materials involved the most work. The gravel and sand must be carefully sieved, sorted by size and thoroughly washed. The backbreaking process requires several days of work in the scorching heat. The two homes were small structures made of mud. The team worked carefully to install the filters. By far, the most difficult task was transporting the 200-pound concrete filter.
The owners will pour 20 liters of water in the morning and 20 liters in the evening for 14-20 days so the filter’s contents can form. After three weeks, the filter can extract 99 percent of pathogens in the water. The next steps involve monthly monitoring and evaluation of the water quality.
Dr. Kerry-Ann Hamilton, director of strategic communications and marketing, is traveling with EWB-HU on their service mission to Kenya. The blog “Water is Life” chronicles the travels and work of the 9-member delegation from Howard University.