About the author

Engr. Azhar Qadri is in the field of rock drilling since last 17 years and looking after Deep Rock Drilling, Tubewell Division. His expertise and involvement in industry for maintaining proper water management system has been greatly enhance capacity utilization of ground water.

An industry, farm or a house without water supply is virtually unusable. The importance of water for daily life with modern conveniences bears this fact out. The most common water supply for the industry that is not served by a public system is a drilled well. Cost of a well is relatively small against the benefits one can tap out from a well. Do not overlook its importance when you are considering hiring a drilling contractor. This fact sheet discusses some important points to consider and investigate before you have a well drilled.

Determine water availability

The geologic conditions or the type of material beneath the ground surface will dictate how much water can be obtained from a drilled well. The ground water survey can provide general information on the ground water availability of an area and by reviewing existing well records and ground water studies on file.

This report will include information on the type of water bearing formation, expected well yield, static water level, and depth to bedrock. Local drilling contractors, drawing on their experience of drilling in a certain area, may be able to give you information on the probable depth of a well, and possibly the quality and quantity of water that can be expected.

Estimate your water needs

Once you know ground water is available, you must estimate how much water you need. To estimate your daily peak water demand, add the appropriate quantities of water for all uses, which would likely occur per day. The ground water may be used directly

where salinity is not the issue. However, generally the treatment is required to use in tailor made fashion.

Existing wells

Last summer, we have worked about 40 water wells. However, in many cases owners do not have full information on their wells. We have never been provided a complete well driller's log or pump curve chart.

The only information available is water system operator experience in operating the well and its GPM. It is very difficult to troubleshoot a well without knowing the depth, the placement of the pump, location of screens, plus other original design specs like pumping capacity and well drawdown.

What to ask

Maintaining the driller's log and pump information is very important. It is the only way to really tell what is going on. A measurement of the water level before and while the pump is running along with amp readings, size of motor, etc. just does not tell you much. When a new well is properly designed (pump size, screens, gravel pack), constructed and developed, for the area alluvial or aquifer and geological formation, the well should have almost 100% efficiency. It should be free of sand and air. After the well is placed in production, there is usually an initial period in which efficiency remains constant. This initial period may continue for many years.

Cost impact

A properly designed well would take less energy requirement comparing to poorly designed. Where hydro geological parameters are considered in proper manner, it is noteworthy that a saving of 2.5 to 7.5 KW hour could be saved.

Quality construction cost would offset immediately, however, in another case the over pumped wells dies very rapidly and hence the return on investment would be poor.

A list of don'ts

n Don't take an individual word that an ample supply of water is available from a well without first sharing information with professionals.

n Don't locate a well too close to sources of contamination.

n Don't drill a well drilled after the building is built.

n Don't hire a well drilling contractor without inquiring about his reputation.

n Don't compare drillers abilities and proposals merely on the per foot prices they charge.

n Don't give the job without a written contract.

n Don't buy a cheap well and poor materials and workmanship may prove to be more costly at later time.

Water management systems must be carefully designed to minimize pumping costs and to prevent excessive drawdown of the well. Like anything a well has a life and it should exist for 25 to 20 years, if no hydro-geological changes are encountered. Poor construction would lead to poor return on investment.