He recently returned from Khulna, Bangladesh, where he witnessed a hand-drilling water well operation and sent this brief report.
This past spring I had the opportunity to do some work in the City of Khulna, in the southwest part of Bangladesh. On one of my daily morning walks, I came across a drilling crew at a hand-drilling operation. I had read about these local drilling techniqes in Bangladesh where wells were hand drilled in alluvial deposits to many hundreds of feet. The drill pipe (1.5 inch diameter) is being lowered by a pulley and turned by hand with a pipe wrench, and the mud pump in the background is being operated by two young men. The well was at a depth of 900 feet and near completion which takes about a week. The cost of drilling is about $300 - $400 USD, and about $200 USD for well completion and pump installation.
Wells in the region are drilled to these deep depths because the “Deeper Aquifer” in southwest Bangladesh is free of the arsenic levels that are problematic in the shallower aquifer systems. Because of the shallow water levels in completed wells and productive aquifer systems, centrifugal pumps can be used for pumping. This particular well will be used to supply a small apartment complex in the City.
Photo 1: Wellhead at Hand Operated Drilling
Operation in Southwest Bangladesh
Here is a PDF of his report (same as contained in this post):
Hand drilling is used quite a bit in the developing world. I have had limited experience with them but know some people who swear by them. This method does have limitations. Here are a few posts about manual well drilling: the Waller and BYU methods and the EMAS concept, which includes more than just manual drilling.
"Half truth is more frightening than falsehood." - Bengali proverb