Process and Chemical

Groundwater Supply and Wellfield Management

Groundwater schemes are commissioned on a yield measured over a few days and then operated for decades, which is why so many boreholes that tested well are now pumping air by the end of the dry season. This course covers managing the resource properly. Delegates work through aquifer types and what each means for sustainable abstraction, then through siting, drilling supervision and the construction decisions that determine borehole life. Test pumping is covered including step and constant rate tests, and interpreting drawdown rather than accepting a driller's figure. Pump selection and setting depth follow. Wellfield operation is addressed, including rotating abstraction and interference between boreholes. Water quality issues specific to groundwater are covered, including iron, manganese, fluoride, nitrate and salinity. Borehole deterioration, screen clogging and rehabilitation follow. Monitoring water levels and abstraction is addressed. The course closes on protection zones, on abstraction licensing and on planning for a failing source.