EL DORADO, Ark. (AP) — The Arkansas Oil and Gas Commission voted Wednesday to close a well that’s used to dispose of natural gas fluids and ban others from being drilled in a gas-rich area north of Conway where hundreds of earthquakes have struck.

Commissioners voted 6-0 to close a disposal well between Greenbrier and Enola that’s operated by Deep-Six Water Disposal Services, a subsidiary of Oklahoma City-based Hurst Oil Investments Inc., the Arkansas Democrat-Gazette reported.

The moratorium would not affect the drilling of natural gas wells, but it would change how fluids from the process are disposed.

Gas companies have tapped reserves of natural gas in the Fayetteville Shale in central Arkansas by injecting water and chemicals under high pressure to fracture the shale, a process known as hydrofracking. Those fluids are injected into separate wells for disposal.

With a moratorium, companies would have to use trucks to get the fluids to injection wells elsewhere in Arkansas or in Oklahoma or Texas, Commission Deputy Director Shane Khoury said before Wednesday’s vote.

The commission pinpointed four wells in central Arkansas that it said needed to be closed. Companies operating three of the wells agreed to close them voluntarily by Sept. 30. Deep-Six, which operates the fourth, says its disposal well doesn’t cause any seismic activity, the Democrat-Gazette reported.

Haydar al-Shukri, director of the Arkansas Earthquake Center at the University of Arkansas-Little Rock, testified Wednesday that his testing recorded nearly 10,000 small seismic events near the Deep-Six well. Most were too small for humans to notice.

Only 280 of those seismic events happened within three miles of the well, a sign that the well wasn’t the cause of most of them, al-Shukri said. “Because of this, I believe at this point, with this data, that there is no correlation,” al-Shukri said.

But Commissioner Mike Davis said the commission had to act to close the well after hearing two days of testimony on whether the injection of fluids was causing earthquakes. A magnitude-4.7 earthquake in February near Greenbrier was the most powerful to hit the state in 35 years. “Our first and foremost obligation is to the safety of the citizens of the state of Arkansas,” Davis said.

And commission director Lawrence Bengal said the Deep-Six well was within the “geologic fabric” of the region and could contribute to earthquakes near Guy and Greenbrier even if the well was several miles from the fault.

“As director, it is not my desire to permit another Guy-Greenbrier swarm to occur,” Bengal said. “I have made my recommendation on a proactive effort in the case of Deep-Six that that not be allowed to occur.”