Prosecutors allege the gas company didn't notify authorities immediately after it learned of the leak. If convicted, SoCal Gas could be fined up to $25,000 a day for each day it failed to notify state authorities about the leak.
After the arraignment, Southern California Gas Company spokesman Mike Mizrahi said, "When we discovered the leak, we made prompt notification to multiple agencies. ... We do not believe a criminal prosecution is warranted here."
SoCalGas reported the leak from its Aliso Canyon storage well on October 26. Prosecutors said in a criminal complaint that the leak began "on or about" October 23.
The flow of natural gas leaking from the well at the facility near Los Angeles was stopped late last week.
The gas company announced that a relief well had "intercepted the base of the leaking well" and operators were pumping fluids to temporarily keep the gas from leaking.
Video recorded Friday showed the leak and emissions in the Porter Ranch area had indeed halted.
"We will continue to work around-the-clock to seal the well with cement," the company said, adding the process will take several days.
In January, California Gov. Jerry Brown declared a state of emergency in the area.
Since the leak was discovered, the California Air Resources Board sent up planes multiple times to measure the amount of natural gas gushing out.
The board measured 97,000 pounds per hour of methane in early November. By late December, about 66,000 pounds per hour were still spewing out.
In December, activists from the Environmental Defense Fund were using thermal photography and video to make the gas plume visible.
Residents of more than 2,200 homes have temporarily relocated.
The gas company, which has been paying for hotels for some, said those residents will have eight days to return home once authorities rule the area safe. People in apartments and rental homes can finish out their leases if they choose.