The success of the water well drilling operations increasingly led to clients asking Drilcorp to provide additional services related to water wells eventually prompting management to create a new division of the company dedicated to non-drilling services. Borehole Engineering Services division was established. This division of the Company has fully trained engineers dedicated to specialist testing, monitoring, surveying, borehole referbishment and remediation and decommissioning of boreholes. The division is also a distributor for borehole equipment and pump manufacturers.
A major UK water supply company approached Drilcorp’s Borehole Engineering Services division (BES) to rehabilitate two of their supply boreholes in the Chalk Aquifer, where elevated turbidity in raw water was causing issues and knocking off the supply. The main objectives of the project were for BES to: (i) assess the extent of the issue at hand and the source of turbidity; (ii) remove iron-oxide slime using their flagship borehole jetting system the Borestorer; (iii) airlift/remove debris and sediment build up at the base of the boreholes; and (iv) disinfect the borehole. Any water produced during the project had to be treated to stringent water quality standards before it could be discharged into a river nearby.
BES carried out the following sequence of operations at the boreholes:
The airlifted water was de-silted in a series of settlement tanks and any free chlorine was neutralized with sodium thiosulphate.
The sequence of operations delivered outstanding results:
No environmental impact on the nearby stream.