A system is needed to assess the potential of a site for well construction. The system should provide approximations of the depth required to dig and any other insightful and relevant information. The solution should also be portable, low-cost, and simple to operate. It should also be possible to manufacture the solution using locally available materials and tools.

If appropriate, the electrical principals and construction of the device would also be used as a teaching aid for the students studying at Vigyan Ashram.

This system would reduce the number of poorly positioned wells, which are either too deep or empty, saving the cost of unnecessary digging, the cost of which is 1000 - 1400 Rs./ft.

Monday 0900 - 1300, 1700 - 2100
Tuesday 1100 - 1500, 1900 - 2300
Wednesday 0500 - 0900, 1300 - 1700
Thursday 0700 - 1100, 1500 - 1900
Friday 0900 - 1300, 1700 - 2100
Saturday 1100 - 1500, 1900 - 2300
Sunday 0700 - 1100, 1500 - 2100

There are also occasional power surges.

Modern well construction is done in three distinct stages. Firstly a hole is cut of diameter 11-15ft to a depth of normally 10ft, and then a narrower shaft is dug on the same centreline to a depth of up to 35ft by either crane pile-driver or blasting (dependant on the geology). The reason for the change in diameters is to allow the excavation equipment to be positioned and to operate below ground level. The last stage is to remove the excavation equipment and brick up the top 10ft or so of the well to give a uniform diameter all the way down the well.

A 35ft depth well will take approximately 1½ months to complete at a cost of 1000-1400 Rs./ft depending on rock hardness. Greater depth and rock hardness leads to a greater cost. Smaller diameter wells situated in homes are not normally done by modern machines.

An electronic system exists already at Vigyan Ashram (a local NGO) for the assessment of well sites and is in active use, though it has limitations. Mr. Anil Gadhe operates the current system and explains that it measures the resistivity of the soil to deduce its water content is in use. The electrical circuit was devised in 1983, and 2405 assessments of potential well sites had been conducted as of 16 July 2005 at up to 200km away. The general test procedure involves inserting two steel pegs 30cm into the ground at varying distances apart and passing current through the earth to measure its resistivity. The current can pass as low as 150 ft below the surface.

However the device is not without its limitations. The test will produce inaccurate results in wet weather or when an electrical charge is nearby (i.e. a pylon). The fieldwork, which is only done in the dry session, takes 2 hours to perform and then the data is manually calculated, plotted and analysed - which is open to human error. The accuracy of the assessment conclusion is approximately 85-90%.

Please refer to the engINdia Final Report for information about the geology of the region.

Vigyan Ashram is home to Fab Lab, a project set up by the Centre for Bits and Atoms at MIT (U.S.). Fab Lab provides hi-tech equipment in developing areas to promote technical know-how and development. A full list of the equipment provided to Fab Lab is provided in the Pabal Document.

Basic household electrics are taught to students at Vigyan Ashram. Relevant staff are capable of assembly of basic electrical circuits, and have a solid understanding of the electrical principals in these circuits. Vigyan Ashram is a learning institution and as such, new concepts are not shied away from if proper educational material is easily assessable. The electrical components and equipment, along with all other materials available, are listed in the engINdia Final Report.

For more information on this project, please contact engindia@mit.edu.