Amathole municipality resumes drilling programme

IN A desperate attempt to find an alternative source of water to stave off the severe drought in and around Butterworth, Amathole district municipality has resumed with a ground water drilling programme.

ADM announced it spent more than 50% of a R9-million allocation from its operational budget for ground water exploration.

The programme, launched in August, has had little success so far mainly due to unfavourable conditions.

ADM spokesman Siyabulela Makunga said Butterworth was underlain by a thick layer of dolerite, an extremely hard rock containing little or no water, so engineers had to drill through the dolerite to depths of 200m to 300m to establish boreholes.

He said a number of the boreholes had either low or no yields.

It was also found that three of the higher yielding boreholes were extremely high in fluoride and therefore unsafe for human consumption.

The ADM said it was still exploring ways to treat the water.

Makunga said engineers had already identified areas with the highest potential in and around Butterworth for boreholes.

“Another area that was initially targeted was around the Xilinxa dam in the hope of supplementing the Kotana Treatment Works.

“The drilling in this area also experienced limited success,” Makunga said.

Scientist at EOH Coastal and Environmental Services Dr Alan Carter said: “Dolerite generally has a very low permeability but it can be a good aquifer if it is highly fractured.

“Dolerite sills can also trap groundwater beneath them to form aquifers, but these aquifers tend to be ‘isolated’ as the dolerite prevents the lateral movement of water underground.”

EOH Coastal and Environmental Services has conducted an Environmental Management Plan for Mnquma Local Municipality.

It revealed that Mnquma (Butterworth) is mainly underlain by red and grey mudstone and sandstone of the Tarkastad Subgroups of the Beaufort group and the Karoo super group.

Certain areas of Mnquma are also characterised by intrusion of Karoo dolerite dykes and sills. The soils in the inland areas of the municipality are generally highly leached soils.

Carter further said it was possible to remove fluoride from water via reverse osmosis.

Other proposed ways to source water in Mnquma included building a 16km pipeline to transfer water from the Tsomo River to the Xilinxa dam. — malibongwed@dispatch.co.za