Words by Julienne du Toit
Photographs by Chris MaraisAlthough most of the furore over potential fracking has revolved around Karoo landowners, it is Karoo towns that are the most vulnerable to groundwater contamination if well casings should fail thanks to shale gas exploration or production, placing hundreds of thousands of people at risk.
Of the 34 sizable towns within or close to the Karoo Basin’s shale gas exploration concessions, 31 depend wholly or partially on underground aquifers for drinking water. Only Cradock, Cookhouse and Adelaide draw solely from rivers for drinking water.
In Shell’s exploration concessions which add up to 90 000 square kilometres of Karoo, there are 16 sizable towns – that depend partially or wholly on groundwater as their primary watersources.
Those that depend wholly on groundwater include Noupoort, Middelburg, Hofmeyr, Tarkastad, Sterkstroom, Richmond, Nieu Bethesda, Murraysburg, Victoria West, Loxton, Fraserburg and Williston.
Towns that draw from a combination of groundwater and rivers include Steynsburg, Somerset East, Bedford and Nelspoort.
In Falcon and Chevron’s concession of 30 000 square kilometres, Aberdeen, Jansenville, Rietbron and Leeu-Gamka depend solely on groundwater, with Merweville able to access a combination on the few occasions when the Van der Bylstroom is flowing.
In Bundu and Challenger Energy’s 3 200 square kilometre concession, Graaff-Reinet draws from a combination of surface water from Nqweba Dam, fed by the Sundays River, and groundwater. Pearston relies solely on groundwater.
In addition, there are also dozens of villages and hamlets that might be affected, as could thousands of farmers and farmworkers (Falcon’s concession alone has 2 500 farms) who rely entirely on groundwater for drinking.
During their public participation meeting in Cradock in March 2011, Shell representatives assured the people present that they would not drill shale gas wells within five kilometres of any town. But they were startled when a representative from the Department of Water Affairs stood up to point out that Hofmeyr, for example, obtains its groundwater 20 kilometres away from the town.
Other large towns that fall close to the boundaries of the various shale gas concessions include Beaufort West, Klipplaat, Venterstad, Prince Albert and Laingsburg (which depend on a combination of ground and surface water) as well as Hanover, Sutherland and Carnarvon, which depend completely on groundwater.
The late Professor Gerrit van Tonder of the Institute for Groundwater Studies at the University of the Free State said the fact that the Karoo Basin is under pressure, has many artesian wells (where water rises from great depth to the surface within days) and is riddled with dolerite faults, dykes and sills makes it uniquely vulnerable to groundwater contamination from drilling.
During 2012 Professor Van Tonder interviewed Andre Els, who used to work with Soekor in the 1960s. Els recounted an incident where the drill bit and drilling fluid with a very particular chemical signature was lost during about 4000 metres underground in a blowout on the farm Skietfontein near Aberdeen.
Six weeks later the same fluid was found to have polluted a farm borehole near Klipplaat, travelling nearly four kilometres upwards and more than 30 km along, probably along a dolerite fault. Dolerite is a known preferential pathway for liquids – farmers seek it out when drilling boreholes. (Find out more about dolerite and fracking here.)
It is uncertain what recourse residents and municipalities would have if their towns’ groundwater was contaminated during or after the shale gas drilling process.
- The water source information for Karoo towns was accessed from the Department of Water Affairs’s Integrated Water Resource Planning.