Brazil court weighs authorising fracking

Brazil's Superior Court of Justice began debating Wednesday whether to authorize fracking for shale oil and gas deposits, with a nationwide decision expected on October 8.

The case concerns an extraction technique used for hard-to-reach oil and gas reserves. Fracking involves injecting water, sand and chemicals underground to break up rock formations where oil or natural gas has accumulated.

The dispute dates back 12 years, when Brazil's National Petroleum Agency auctioned several unconventional deposits in western Sao Paulo state. The public prosecutor's office blocked their exploitation.

Fracking has been used in thousands of Brazilian wells, but some states have passed local bans to prevent environmental damage, and courts have blocked projects on similar grounds.

The National Petroleum Agency argues that current environmental regulations are sufficient. The public prosecutor's office warns that there are scientific uncertainties about serious and potentially irreversible risks and wants fracking to depend on a prior study demonstrating its safety.

Environmental concerns linked to fracking include possible groundwater contamination and induced earthquakes. Brazil is the world's ninth largest crude oil exporter, and the oil industry considers fracking a new frontier.