What USAID, SKAT, RWSN and UNICEF don't do, costs human life.

There is no doubt that USAID, SKAT, RWSN and UNICEF have done more to improve water access and save life than any organizations in history. However, we all could use a little improvement (especially me). When one looks at the shear volume of literature that these organizations have produced regarding water and wastewater, it is staggering.

There is a problem that all these organizations share. They all fail to give sufficient instruction on how to avoid producing a well with a high probability of failure. Looking at years of publications by these organizations, one can find no consistent instruction on when to change drilling method, when to stop drilling and abandon a well, when to use drilling mud, when to avoid drilling mud and generally what to do when things go wrong. There is also poor guidance with regard to well development and pump installation. There is really no guidance with regard to what to do when a well produces sand, is too shallow or the type of pump is not ideal. These are all serious problems, and resolving them can cut the water point failure rate from 30 percent to a much lower percentage.

There is no mention in these organization's literature of the best method of hand drilling boreholes, which is air lift reverse flow. The air lift reverse flow method can be used in nearly every situation to repair the damage caused by the initial use of a risky drilling method.

Because of the omitted information regarding well failures, by all of these organizations, we find ourselves at the high failure rate we have today. Not because the publications are poorly written, but because the subject matter is incomplete. Each organization needs to have a "borehole risk section" in their literature where they focus on the fact that 30 to 60 percent of boreholes fail. They need to clearly and concisely define why boreholes fail and how to repair them ---during the development stage, pump installation or at the end of the drilling process while the original crew is on site. And some boreholes need to be abandoned, because water cannot be guaranteed to be available at every location. The organizations do not need to recite the methods that may be used, or any other information within the borehole risk chapter except for information regarding the verified facts of the cause of failure and the weaknesses of the systems of installation. People need to be informed as to the risk of failure, failure modes, the weaknesses in the installation methods and the fact that borehole sites are not uniform models. And they need to be warned about the facts regarding well development, the impact of drilling mud and a thousand other problems that will pop up once a plan is made to drill a borehole. Drillers and inspectors that are informed as to causes of an increased probability of a borehole failing are less likely to continue to install poorly placed or installed boreholes.

-----------------------------------

This is an example of the guidance that should be provided in the various manuals or within addendums that are available to be used in drilling courses.

Example:

• A small village needs a source of water in an emergency and has limited funds. Local codes require at least a 200 mm casing with a 5mm wall. A crew is hired during the rainy season to use the auger method of drilling, entirely due to a perceived cost advantage over other methods. Recorded drilling logs indicate that in this area there is 3 meters of soft clay, followed by a first aquifer defined by a seam of 1 meter of silt followed by 2 meters of fine sand then 5 meters of clay above an second aquifer with a 10 meter thick seam of <2" gravel and course sand. Total depth of the well is to be 16 meters. The anticipated static water table is at 2 meters during the rainy season. Local wells founded in the first aquifer have increased risk of contamination and normally produce little water in the dry season.

A borehole drilling crew is hired with the understanding that their price is based upon using the auger method to drill a borehole to a depth of 16 meters with 5 meters penetration into the second aquifer.

An astute observer would look at the above outline of the drilling report and advise the village that the chances of obtaining a high quality water point with the auger system, under the conditions outlined above would be unlikely. First the method of auger drilling is not ideal when one must drill through one aquifer to get to a second aquifer.

In fact choosing a method of borehole drilling in this situation would be tricky. The presence of clay and multiple aquifers limits the cost effectiveness of most methods of drilling. For example the percussion and bailing method would require expensive casing and there would be a chance of flowing sand. The auger method would require casing as well along with the risk that the silt and fine sand would flow into the casing. And the jetting method would have difficulty with removing the 2 inch and smaller gravel. Because of the gravel, the sludging method would be unsuitable. In addition, the jetting method could inject thixotropic materials into the gravel and course sand aquifer and increase the risk that the aquifer would no longer be dependable. Using the current guidelines of the above organizations, there is no option to drill with a reverse flow, so that is not in the mix.

After some discussion within the village , and because they are unaware of the reverse flow method, the village will likely take a risk and go forward with the use of the auger system. As a result the village is likely to own a failed borehole within a short period of time and will have wasted its time and money. It is highly likely that using the auger system with casing will lead to a well where the final depth will only touch the second aquifer because of flowing sand and the inability of the auger system to bring up the large gravel. Water will be found at that location, however it will likely go dry in the dry season and the borehole will likely pump fine sand and ruin any hand or power pump that is installed.

It is important to note that - had- the major organizations listed above notified their drillers that the reverse flow method was allowable, the entire drilling process would have been easily accomplished. The reverse flow process will penetrate the clay, silt, gravel and sand easily and the cost is actually less than using the auger method in this situation.

The photo above is of a crew using the reverse flow method to drill 120 ft. deep and 8 inches in diameter in India.