Having learnt about the general process of drilling a borehole (here), the role of hydrologists in the process (here) and the role of environmental experts (here), in this piece we look at what the client should do to ensure the best results in a borehole drilling exercise.
In the context of borehole drilling, the client is the project proponent. He/she initiates the project, finances it, and is the primary user of the borehole installation upon completion. Unfortunately, in many cases, the client may not be conversant with the process of borehole drilling, more so the regulatory approval process and the technicalities involved in the drilling exercise. In this case, it is always advisable for the client to hire a reliable consultant to guide him/her through the process. The consultant should be a person with sufficient know how of borehole drilling-this may be either a hydrologist, an engineer or an expert with proven experience in the water industry. Usually, the client will enter into a drilling contract with a drilling company, referred to as the contractors, and the consultant will act as the project engineer or supervisor. Thus, first and foremost, the consultant should guide the client on the best type of contract to sign with a drilling company.
1. Checklist – Drilling contract type selection
Some of the common contracts worth noting include BQ contracts and lump sum contracts. The former type of contract is dependent on the quotation shared by the contractor. Once the quotation is accepted, the responsibility of striking water or failing is left squarely on the contractor. In that regard, failure to realize a water strike will result in no payments on the part on the client. Lump sum contracts, on the other hand, will have client’s agent (the consultant) as responsible for supervising the contractor. The client is only expected to make payments after a water strike. All other costs are covered by the driller and the client reimburses him/her upon striking water. The danger in this type of contracts is that some drillers may take advantage of the seasonal variations in the water table to drill a seasonal borehole so as to benefit from the pay- after-water strike clause in the contract. The consultant should be able to foresee some of this issues and act accordingly.
2. Checklist - Responsibilities of the consultant
Beyond guiding the client through contract selection, the consultant should be responsible for all the major decisions in the project together with any form of supervision required. Specifically, the contractor should:
a. Share and validate client requirements from the borehole survey and drilling all the way to equipping the borehole
b. Share with the client results from the hydrological survey and confirm the reliability of the methods used by the hydrologist in the survey
c. Facilitate the acquisition of any necessary documentation, including permits, before the drilling starts
d. Mobilize the assembly of the drilling rig on site and implementation of the schedule of works
e. Together with the contractor, he/she should select the proper casing and piping material based on the water type, drilling depth and geographical location of the project
f. Inform the client once at least 3 water strikes have been realized during the drilling exercise
g. Supervise pump testing to ensure that at least a 24 hour testing period for reliability of results and to prevent the use of fraudulent pump test results
h. Submit a comprehensive drilling report with information on water strikes, casing perforations, water quality etc.
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