Kevin McCray sent me this MS thesis from Mercer University, The Development of a Low-Cost Lead Free Wellpoint Drilling System For Use in Household Well Systems in Coastal Areas of Madagascar by Andrew A. Wohlrabe.
The title suggests the approach is appropriate only for coastal Madagascar conditions but that has to do primarily with the materials employed, not the technique, which could be modified for use in other regions.
In eastern Madagascar Pitcher Pump systems containing leaded components in the pump head and the drilled well are widely used. The ingestion of lead (Pb) in any form can be very harmful to humans. Previous research has measured lead in these systems, and recommended a way to eliminate the use of lead in the pump head. The purpose of the current study is to develop a cost-effective, lead-free alternative drilled well system. Three alternative methods, the Cased System, Exposed-Screen System A, and Exposed- Screen System B, were designed and tested. A total of nine wells were drilled over a span of two drilling phases at USF’s GeoPark in Tampa, Florida. Of the three methods, the Exposed-Screen System B Method, a modification to Exposed-Screen System A, proved to be the most successful. It was also the simplest design, required the least amount of equipment, and was the most cost-effective. This method was modified for testing in Madagascar. Modifications were necessary to accommodate for material availability. The newly developed method was called the Madagascar Exposed-Screen System. Two wells were successfully installed, removed, and examined using this method. Future recommendations include further research into specific materials to be used in drilling and additional testing in eastern Madagascar.
"Learn what is to be taken seriously and laugh at the rest." - Hermann Hesse (in The Week)