RWSN Topic

An Introduction to Manually Drilled Wells

Hand drilling is also known as manual drilling, human powered drilling, and is sometimes referred to simply as low cost drilling. As the names suggest, hand drilling technologies primarily utilise human energy.

The cost of a manually drilled well can 10% to 50% of machine drilled or hand dug well to similar depth. Hand drilling equipment can often be readily taken to sites which larger, more conventional drilling cannot access. However, it is important to note that hand drilling techniques are extremely effective in appropriate ground conditions. They are not suitable beyond their hydrogeological limitations. In cases where the formation is too hard, or the water bearing formation too deep, conventional drilling is the preferred option.

The videos below illustrate just one example of an approach to manual drilling:

To see the full set of videos go to the Manual Drilling: Water4 Training page.

Courtesy of Water4 Foundation

 

Unlike hand digging, which requires a person to be physically below ground to dig the well (of at least one meter in diameter), hand drilling enables the operators to remain above the ground and drill a narrow diameter borehole (50 to 200mm). Hand drilling can provide highly affordable improved groundwater sources for households and communities for both domestic and productive use. Drilled depths depend on the technology and formation, but can extend to 30m and sometimes more.

 

The auger method involves penetrating the ground with a small-diameter borehole with a cylindrical or helical soil auger. This method can penetrate certain sands and silts and some clay formations.

Hand percussion and stonehammer drilling involve the lifting and dropping a cutting tool suspended at the end of a rope. They are dry techniques, only adding a little water in order to remove the spoil (drill cuttings).

In contrast to the above, the jetting and sludging methods use considerable amounts of water to wash out the spoil. Jetting (also known as washboring) and the EMAS technology inject water down and out the bottom of a drilling pipe to wash the spoil up to the surface. Self-jetted well-screens are an improvement of the original jetting technique. The use of a cutting point when jetting enables more compact materials to be drilled. A tripod (or derrick) enables the technique to penetrate deeper. The EMAS technique uses a percussion action coupled with back and forth rotation of the drill bit to break the formation, whereas jetting is designed to penetrate mainly sands and silts with the force of the jetted water.

Sludging and its more recent modifications (Baptist, Rota Sludge and Pounder Rig) are all continuous drilling methods that allow the drilling fluid to flow down the annulus (ie the gap between the drill pipe and the drilled hole) and carry the cuttings up through the drill pipe. The Baptist method, Pounder Rig and Rota sludge have all tried to penetrate harder formations, with varying success. The Pounder Rig places the more emphasis on drilling of a vertical hole, whereas the Baptist and Rota Sludge techniques emphasise very low cost wells. The Baptist and Rota Sludge techniques can be combined with stonehammer drilling to penetrate harder formations (eg laterite) whereas the Pounder rig is already designed for this.

For a comparison between different hand drilling methods and other drilling techniques see:

  • Human Powered Drilling Technologies.  An overview of human powered drilling technologies for shallow small diameter well construction, for domestic and agricultural water supply by R.C. Carter, Cranfield University at Silsoe, UK
  • Simple drilling methods.  A technical brief which outlines simple, low cost drilling methods which may be used in different situations by B Elson and R Shaw, WEDC, Loughborough University, UK
  • Low-cost shallow tube well construction in West Africa by M. Sonou, FAO, Italy.

Hand drilling techniques are extremely effective in appropriate ground conditions but are not suitable beyond their hydrogeological limitations.

These webpages are intended to enable more information exchange and discussion on hand drilling.  They are by no means exhaustive.  Please tell us more about your hand drilling experiences, projects that you know about or equipment suppliers.


Related Resources

Professional Water Well Drilling

A UNICEF Guidance Note

This guidance note provides practical guidance for organisations and individuals that are trying to raise the professionalism of groundwater development in Africa. The guidance note is mainly concerned with rural and small towns’ water supplies but is mindful of the huge challenges faced by supplies in many growing African cities dealing with problems of groundwater quantity and quality.

DOI: 10.13140/RG.2.2.21914.64964 | more information »

Upgraded Family Wells in Zimbabwe (2012)

A study of Upgraded Family Well technology and training

Several years ago Zimbabwe embarked on a program of upgrading family owned wells. This program was fully endorsed by the GOZ and operated under the MOHCW. The program has been well documented in papers and other publications. This program was based on the fact that for many decades individual families had chosen to upgrade their own wells privately and outside the formal GOZ rural water supply and sanitation program. In the early 1980’s the number of family owned wells in Zimbabwe was estimated to be at least 100 000. Many of these were lined with bricks and had some form of head works. Many were fitted with windlasses – a legacy from the mining industry. The windlass made the bucket easier to lift and also retained the rope or chain in a hygienic position above ground. However the majority of family owned wells were poorly protected and open and were subject to contamination, especially during the rainy season and were also dangerous for children. | more information »

Evaluation of Hand Augered Well Technologies’ Capacity to Improve Access to Water in Coastal Ngöbe Communities in Panama

MSc thesis submitted to University of South Florida 2014

In Panama, the indigenous Ngöbe people in the ÑöKribo coastal area are a group disproportionately affected by a lack of improved access to drinking water and challenges to the feasibility of piped gravity fed water systems that typically serve the rest of the country. An NGO aiming to ameliorate this situation introduced two improved groundwater supply technologies to the region: bailers and EMAS hand pumps. This study assesses the comparative performance of these systems while evaluating the respective performances of existing water sources, using the wide variety of quantitative and qualitative data obtained.

DISCLAIMER: This is a non-RWSN publication and endorsement by RWSN or any of its member organisations should not be inferred. | more information »

Hand drilling a shallow tube-well in Zimbabwe and fitting a simple “Bailer-bucket” for water lifting

The construction of the lighter duty, simple hand operated drilling rig has been described in another manual and was designed for drilling shallow tube wells in softer soil formations, which occur in some areas of Zimbabwe. Currently the drilling stems extend to a maximum of 12m. Staff members of the Ministry of Health and Child Welfare are familiar with local shallow ground water conditions in Zimbabwe. A depth of 12m is suitable for the use of this simple rig in combination with simple water raising devices like the “Bailer-Bucket” Pump and Blair Pump.
This manual describes the test drilling of a tube-well in Epworth, near Harare, Zimbabwe and the construction and fitting of a PVC casing and filter mechanism. It also describes the construction of a simple “Bailer-Bucket” pump and the head works at the head of the tube well. Of particular significance is the part played by the family itself by making the water raising device – a tubular bucket fitted with non-return valve and handle. The design of the “pump” is very simple and easily made within the home. The chances of continued operation and maintenance are this considerably improved. | more information »

- Atelier Final, Dakar, Senegal, 8 Avrill 2015: Utilisation de la télédétection et de la modélisation du terrain pour l'identification des zones favorables aux forages manuels

- Final Workshop, Dakar, 8 April 2015: Remote sensing and terrain modelling to identify suitable zones for manual drilling in Africa

This set of presentation was given at the closing workshop in Dakar, 8 April 2015 of the UPGro Catalyst project : "Use of remote sensing and terrain modelling to map manual drilling potential in Senegal and Guinea" | more information »

Chad’s Growing Manual Drilling Industry

In Chad, manual drilling is a growing industry. This report provides an overview of manual drilling in Chad today. The report is intended to stimulate interest in more research, documentation and action regarding the diffusion of manual drilling within the country and its implications. The technology is increasing in popularity and spreading within Chad, including in the capital N’Djamena. Private enterprises and non-governmental organisations are promoting manual drilling and water users are investing in their own manually drilled wells. | more information »

Manual Drilling Compendium 2015

RWSN Publication 2015-2

Manual drilling refers to several drilling methods that rely on human energy to construct a borehole and complete a water supply. The various techniques can be used in areas where formations are quite soft and groundwater is relatively shallow.

Manual drilling can provide safe drinking water. The equipment can easily be transported to remote, or difficult to serve populations which would otherwise be left behind. The lower costs compared to machine drilling are appreciated by households, businesses and governments. Manual drilling also provides local employment.

Manual drilling methods are being used to provide water for drinking and other domestic needs at least 36 countries around the world. In some places, manual drilling methods are well established.

The compendium provides a useful overview for those wishing to further examine the impacts and challenges of manual drilling, and, more importantly, improve practices on the ground. It is hoped that the document will spur others to undertake fur-ther studies as well as research to document stories and analyse the promotion, uptake and use of manually drilled boreholes. In addition, the compendium should also enable those promoting manual drilling to realise that they are certainly not alone in their endeavours! | more information »

RWSN Webinar Series 2015

Presenters from more than 25 different organisations, working in over 20 countries share their practical experiences and research findings. Participants have the opportunity to ask questions, and meet others with similar interests at the events. Topic covered include:
- radio for rural water supplies, drawing on practical experiences from Kenya and Tanzania.
- Self-supply in emergency and development contexts, and we shall be hearing from Sierra Leone as well as Ethiopia, and on the costs and quality of self-supply as well as government roles.
- a series of webinars on groundwater.
- experiences about dealing with gender, violence and access to WASH
- rainwater harvesting
- etc.

All of the presentations and links to the recordings will be posted here within two to three days of each webinar. | more information »

Manually Drilled Boreholes: Providing water in Nigeria’s Megacity of Lagos and beyond

The Rural Water Supply Network (RWSN) is continuing its work on cost-effective boreholes under its theme of Sustainable Groundwater Development. The network is supporting stakeholders to improve borehole drilling policies and practices. As part of this effort, UNICEF and Skat Foundation are collaborating on manual drilling in Africa. The 2012 to 2014 collaboration documented and facilitated exchange on the introduction and professionalization of manual drilling in more than 20 countries.

This report is about the role played by manually drilled boreholes in meeting water needs in Lagos city, Lagos State and more widely in Nigeria. By examining Nigeria, the report draws out key lessons for those who are promoting, or trying to regulate manual drilling in other countries. It is hoped that this report, and the accompanying photo/video documentary and blogs will trigger action to better support manual drilling efforts in Lagos, in Nigeria and in other countries. | more information »