Johannesburg - Government must stop the legislative process underway to regulate shale gas exploration until it has considered all the evidence, the Treasure Karoo Action Group (TKAG) said on Monday.
This follows the US state of Pennsylvania's department of environmental protection releasing information that indicated drinking water had been contaminated by fracking, TKAG CEO Jonathan Deal said in a statement.
The Associated Press reported on Thursday the department had released details of 243 cases where companies prospecting for oil or gas were found by state authorities to have contaminated drinking water.
The 243 cases, from 2008 to 2014, included some where a single drilling operation affected multiple water wells.
AP reported that the problems listed included methane gas contamination, spills of wastewater and other pollutants, and wells that went dry or became undrinkable.
Fracking, or hydraulic fracturing, involved pumping a pressurised mixture of water and chemicals deep into the ground to extract natural gas trapped in shale layers.
Deal said the TKAG had written to mineral resources minister Ngoako Ramatlhodi in connection with the Pennsylvania cases.
"There are many reasons why this information has been concealed and continues to be concealed from the public", he said.
"As with all issues of this nature the truth will eventually emerge, as has happened now in Pennsylvania."
The TKAG said the cases in Pennsylvania had emerged at an important time.
The mineral resources department's director general Thibedi Ramontja told Parliament's mineral resources portfolio committee on Wednesday that public consultations on draft regulations for shale gas exploration would begin in September.
Ramontja said technical regulations for fracking would be finalised after the consultations. After final regulations had been determined, licences would be processed and issued.
Applicants would be bound by strict regulations to ensure government mitigated against any environmental impact, including ground water contamination.
"I am confident that in the event there are problems, they will be picked up quickly if there's any threat to water in that area [Karoo]", Ramontja said.
"I'm confident water will be protected."
Deal said not only did the information from the US disprove claims by companies and government that fracking was safe, it validated concerns the TKAG had raised since 2011.
Julius Kleinhans, environmental affairs head at civil rights group AfriForum, said while the department emphasised drilling would take place, it had not provided adequate answers on its ability to monitor the industry.
"It concerns us greatly that [Ramontja], failed to acknowledge the limits of the department when it comes to monitoring and law enforcement", Kleinhans said.
"Monitoring alone will not protect water resources and the draft regulations for shale gas mining are questionable at best and inadequate at worst. It is a recipe for disaster and a huge uncalculated risk."