For the field operation, first, background SEC at 25 °C in μS of the borehole water was taken with a Heron temperature, level, and conductivity (TLC) metre logger. Metal weighted hose pipe injectors were inserted into the 100- and 50-m deep wells. After this NaCl was dissolved in a calculated volume of water, mixed thoroughly, and injected uniformly along the water columns in the wells (see injection parameters in Table 1) via the injector.
Borehole and NaCl injection details
| Well coordinates/terrain . | Ground elevation (m.a.s.l.) . | Well depth/open section (m) . | Depth to water table (m)/Casing length (m) . | Borehole diameter (mm) . | Salt mass injected (g)/volume of water in well (L) . |
|---|---|---|---|---|---|
| 5°17′21.9″N 2°00′37.3″W/Hilly borehole | 103 | 100 m, 45–100 mbgl | 13, 45 | 140 | 1,000, 1,339 |
| 5°17′58.00″N 2°00′08.04″W/Valley borehole | 76 | 50 m, 10–50 mbgl | 8, 10 | 140 | 608, 639 |
| Well coordinates/terrain . | Ground elevation (m.a.s.l.) . | Well depth/open section (m) . | Depth to water table (m)/Casing length (m) . | Borehole diameter (mm) . | Salt mass injected (g)/volume of water in well (L) . |
|---|---|---|---|---|---|
| 5°17′21.9″N 2°00′37.3″W/Hilly borehole | 103 | 100 m, 45–100 mbgl | 13, 45 | 140 | 1,000, 1,339 |
| 5°17′58.00″N 2°00′08.04″W/Valley borehole | 76 | 50 m, 10–50 mbgl | 8, 10 | 140 | 608, 639 |