(CNN) Natural gas had been spewing out at a rate of up to 100,000 pounds per hour from a spot above Christy Rocco's home for weeks, and her family had been getting sick.

So, when California Gov. Jerry Brown declared a state of emergency Wednesday over the colossal leak near the Los Angeles suburb of Porter Ranch, it felt a little late.

SoCalGas reported the leak from its Aliso Canyon storage well on October 23.

"Why didn't it (the state of emergency) come 12 weeks ago?" Rocco asked. "When they came forth with it?"

Smell of propane

Rocco's family first noticed an annoying eggy smell.

"It started just kind of being frantic and wondering why our house smelled like a propane tank for weeks on end -- looking for it." But since natural gas is invisible, they could not see it gushing skyward right up the mountain from them.

Rocco's husband and son came down with profuse nosebleeds, her daughter had recurring headaches and nausea, and Rocco herself had nagging respiratory problems.

Around Thanksgiving, when the family heard about the leak, to them, the source of their ailments was obvious, so they moved into a hotel.

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For months to come

In the meantime, SoCalGas was figuring out how to plug the deep pipe that sprang the leak.

It could take until late February or late March to properly find the leaking pipe and drill down 8,500 feet to plug its source with concrete, the governor's office has said.

Drilling must proceed slowly, in part so it doesn't puncture adjacent pipes and spring new leaks.

The California Air Resources Board sent up planes multiple times to measure the amount of natural gas gushing out.

'BP spill on land'

The board measured 97,000 pounds per hour of methane in early November; markedly higher later in the month. 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. Aliso Canyon is the largest gas storage well in the western United States, and before Thanksgiving, the leak had expunged about 2% of its contents, the Environmental Defense Fund said.

Methane is a greenhouse gas much more potent than carbon dioxide, and the environmentalists said the leak had already contributed as much to the greenhouse effect as nearly 3 million metric tons of carbon dioxide.

The Environmental Defense Fund called the Aliso Canyon outflow a "mega-leak."

She rose to fame when she fought another natural gas company over water pollution in the 1990s. Her struggle was made into a feature film.

Brockovich lives in Agoura Hills, some 20 miles away, and has taken up the cause of local residents' concerns.

'Gas is not toxic'

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As to health complaints like those Rocco's family experienced, SoCalGas has said the leak doesn't pose an imminent risk.

"The well is located in an isolated, mountain area more than a mile away from and more than 1,200 feet higher than the closest home or public area. Scientists agree natural gas is not toxic and that its odorant is harmless at the minute levels at which it is added to natural gas," the gas provider said in a statement.

That odorant is mercaptan. It smells like rotten eggs and it is added to natural gas, which is odorless, to alert people to its presence to prevent them from inadvertently igniting it.

SoCalGas apologized for the smell but said it posed no threat.

Dizziness, nausea

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"As far as scientists currently know, methane is not a long-term health hazard," it said. "However, more research is probably needed to completely understand the long-term effects of methane exposure."

In high concentrations, methane exposure can decrease oxygen intake and cause headaches, nausea, vomiting and dizziness, the U.S. National Library of Medicine has said.

California's health department held a community meeting in Porter Ranch on exposure to methane and mercaptans, saying nausea, dizziness, vomiting, shortness of breath and headaches are among the health complaints "consistent with inhalation exposure to mercaptans."

'Sick all the time'

Brockovich bristled at SoCalGas' message that the leak poses no imminent danger.

"This 'can't hurt you' has got to stop," she said. The leak has also been spewing traces of oil, and residents have complained about residue, she said.

SoCalGas has installed a mesh around the leak site to catch it.

Brockovich organized a town hall-style meeting for concerned Porter Ranch residents to put their questions to lawyers and health experts.

A woman stood up in the crowd of hundreds seated in an auditorium and was handed a microphone.

"I've been smelling rotten eggs at the school since the beginning of the school year," she said. "I have a 1-year-old; my baby's sick all the time, runny nose all the time. My 5-year-old that goes to that school wakes up congested in the middle of the night crying all the time, wakes up and is stuffed up. So, is this all from the gas?"

A local trauma doctor tries to help her with an answer. Aside from the mercaptan, natural gas often contains trace amounts of hydrogen sulfide, which can cause respiratory damage, he said.

Resident Yitz Dekel had "inexplicable fatigue" before he left his home for a hotel, he told CNN a month ago. He said his wife experienced some dizziness.

"And my neighbors, some in ill health, had major coughing and irritation in the eyes and throat. Some had nose bleeding," he said.

'So disoriented'

Rocco pulled her daughter from school after she had nosebleeds there. The children were not allowed to go outside, and some became nauseated and vomited, she said.

She and her family are no longer in the hotel, as SoCalGas has provided them with a leased house. Altogether, residents of nearly 2,290 households have been moved.

"We've been so all over the place and so disoriented," Rocco said. The company regularly sends her apology letters, she said.

She has lived in Porter Ranch for 25 years and loves it there. "I'm devastated at the thought of never being able to go back there," she said.

Her family recently drove by to have a look at their house. There was a white film on the sidewalk. She looked up at the work zone surrounding the leak. "It's directly above us," she said. "We look right up at it."

Rocco's worst fear is having her home transformed into an irreparable health hazard.