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Groundwater mapping for safer fracking CA Oil & Gas

Concerns over the dangers of fracking might have found a solution in groundwater mapping.

What is fracking?

Fracking is the process of drilling down into the earth before a high-pressure mixture of water, sand and chemicals is directed at a rock to fracture the rock and release the gas inside. Fracking allows for greater gas extraction as difficult-to-reach oils and gasses can be reached. The process is very popular in the United States of America, where shale gas extraction production has increased from about 1 to nearly 16 trillion cubic feet (tcf) over the past 25 years. It has also lead to the lowering of oil prices worldwide. This process could help alleviate South Africa’s dependence on coal for energy. The Karoo in South Africa has been earmarked as an area with shale gas potential. Guesses put the upper limit for gas in the Central Karoo at about 20 tcf, which is small in comparison to global standards. However, even a small gas find has the potential of transforming the national energy economy. There have been many concerns raised over the introduction of fracking in the Karoo.

The dangers of fracking:

With fracking, extraction can often include aquifer damage. An aquifer is an underground layer of water-bearing rock from which groundwater can be extracted using a borehole. During oil and gas extraction, an aquifer can experience dewateringdeformation, and contamination. Often, this damage is irreversible, and leads to the contamination of the locations. As such, fracking can lead to environmental damage. Research done into the effects of shale gas extraction in South Africa have found that there were no extra groundwater resources available in the country and that fracking operations would impact existing ones. This report also found that shallow groundwater resources in these water scarce areas may be contaminated by fracking operations. In addition, fracking could lead to social disruption, the increase of small earth tremors as well as the accompanying habitat fragmentation and disturbance.

The importance of groundwater

Whilst groundwater only contributes about 13% of the total water supply of South Africa, two thirds of South Africa’s surface area and more than 300 towns depend largely on groundwater for drinking water. As such, groundwater is incredibly important to many South African communities.

The proposed solution: groundwater mapping

Scientists have developed a groundwater vulnerability map to help alleviate some of these concerns of damage. Groundwater mapping will provide the location of sites where the groundwater resource is at risk due to a potentially damaging event linked to fracking, which could cause pollution or destruction of this resource. Baseline monitoring of groundwater resources and the development of baseline vulnerability maps that show the location of sensitive groundwater resources are important tools that may assist governments in their decisions to allow, or not allow, Unconventional Oil & Gas (UOG) extraction in certain fragile areas and may aid in the regulation of UOG extraction in sensitive aquifers. This information can also directly feed into an adaptive management plan by reducing uncertainty in our understanding of the effects of UOG extraction and risks to natural resources and humans.

The map ranks areas on a scale of very low to very high vulnerability. Those marked as having very high vulnerability should not be explored. The map also shows the location of geological structures where groundwater is more vulnerable to oil and gas extraction, because contamination from for instance spillages can enter the groundwater easier at these locations. Protection zones have been drawn around these vulnerable geological structures and no oil and gas development activities should occur within these zones. As such, groundwater mapping will be beneficial in protecting the vulnerable environment.

Government’s role

The risks associated with shale gas extraction would need governmental intervention. Government would need to create an enabling environment to encourage investment in the industry while also ensuring that the state and local communities benefit. Governmental structures should facilitate and coordinate extraction activities. It is also critical that there is clarity regarding the pricing structures that may prevail. This is crucial when the industry begins to exploit the shale gas reserves, and obviously requires a clearer understanding of the potential quantum of the known reserves.

What do you think? Should fracking in the Karoo go ahead? Let us know in the comments below!

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