Now that a design has been decided upon, we put together a shopping list. We wanted to use both easily sourced materials as well as inexpensive ones. We thought scrap metals would be the best material for this and we went to the market. To gather all the materials, both for the framework and for the stirring apparatus, we spent about three afternoons at the market. On Wednesday, we met with Dr. Mkandawire, who said we were on the right track. Despite earlier discouragements that building would be a misguided project, she believed that we should still put forth efforts to devise a treatment system even if it might fail in the field because it would all be part of the learning process.
On Thursday, we had a scheduled trip to the Blantyre Water Board’s collection and treatment facility at Walkers Ferry. We hoped that by visiting the municipal water treatment system, we would have a better understanding of how water treatment works in general and what the standards are for the Southern Region of Malawi. A four-stage process—extraction, sedimentation (several sub-stages), filtration, and finally chlorination—was used to supply over 90% of the required water to Blantyre. A set of pumps, tanks, gages, as well as a large contact tank to store the chlorinated water before being pumped to Blantyre, proved the complexity of water treatment. Our system hopes to combine sedimentation and treatment into one bucket, filtration as a step between the two buckets, and then clean water in the bottom bucket.