South Africa is reviewing its water regulations to guard against damage to the environment from the exploration and extraction of shale gas after opposition from green campaigners and farmers to the drilling technique.

“Our key priority is protecting the environment and our water resources,” Water and Environmental Affairs minister Edna Molewa told reporters today in Pretoria. “We will take every precaution to ensure that the possible impact of fracking on our water is carefully managed and minimized.”

South Africa’s shale reserves, concentrated in the semi- desert Karoo, may be the world’s eighth-largest, the U.S. Energy Information Administration said in June. Royal Dutch Shell Plc, Chevron Corp. and Falcon Oil & Gas Ltd. are among companies that have a applied for permits to explore for the gas. Campaigners say the industry may destroy the area’s fragile ecosystem.

Gas is pumped from shale using hydraulic fracturing, or fracing. The government estimates gas sales may generate 1 trillion rand ($97 billion) within three decades and help bring a country that imports 70% of its crude oil needs closer to supplying its own energy demand.

The government declared shale gas extraction a so-called controlled activity needing a water license that’s only issued once the effect on ground water is taken into account.

The water review will also include policies such as whether the state’s allocation of 25 liters (6.6 gallons) of free water a person each day is adequate. The country is also considering stripping parties of allocated water rights if they aren’t used within a specified period, Molewa said.