Maintenance & Repairs
The life of a borehole will be limited unless it is constructed in a manner which permits both, high initial efficiency and the possibility of periodical redevelopment, and only if it is pumped at the proper design rate. With the use of appropriate materials and with careful maintenance, a borehole may be productive for 20 years or more.
Boreholes may decline as a response to:
i) Lowering of water table levels;
ii) Inefficient pump operation caused by worn, corroded or plugged parts;
iii) Deposits of scale, corrosion products or micro-organism growth on the screens and casing;
iv) Clogging of the screens by mud, silt or sand.
Borehole maintenance and rehabilitation actions help in recovering lost production if the decline is due to any of the last three causes. Repair and maintenance work can be accomplished at opportune times and complete breakdowns avoided. Most groundwaters are only mildly corrosive, if at all; corrosion may be offset by using protective coatings or corrosion-resistant materials for the screens and casing.