The leak at the Aliso Canyon natural gas storage facility has given rise to lots of questions and rumors among residents of Porter Ranch and adjacent communities.

Here is a rundown of some of the most persistent rumors and what we've been able to find out.

Did the leak really begin Oct. 23?

SoCalGas says the uncontrolled leak of natural gas from a well known as SS-25 was discovered Oct. 23. Some residents have posted on a Porter Ranch gas leak Facebook page that they had been experiencing symptoms and illnesses before that.

Here is what L.A. County Public Health Department says:

"Odors may have existed in this community at a lower level before this gas leak was discovered. Public Health has never received a health complaint associated with an odor from Porter Ranch before this event. However, Public Health will continue to monitor this issue for a period of time after this leak has been sealed, so that we can determine the baseline of odor complaints in the community, and further determine the potential sources of these odors."

Did "fracking" cause the leak?

At an state Assembly Utilities and Commerce Committee hearing in January, a state official testified that hydraulic fracturing (injecting fluids at high pressure underground to increase the flow of oil or gas) had occurred at the Aliso Canyon gas field, but not within one-quarter mile of the leaking well known as SS-25.

Is radiation coming from the leak or the underground gas field?

A recent Forbes article about uranium extraction in Texas got people talking about the potential for radiation poisoning in the Porter Ranch area. Another article from a website called Superstation95 said "lethal levels" of uranium and radon gas were poisoning the area. Also, a company has been mailing radon detection service offers to are residents.

A SoCalGas spokesman declined to address the topic of radiation at Aliso Canyon, saying the rumors were started by a very inaccurate news article that he declined to identify.

There is no evidence or concerns about uranium radiation coming from the Aliso Canyon gas storage field, said Dr. Cyrus Rangan, director of the Toxics Epidemiology Program of L.A. County Department of Public Health. He said reports to the contrary on the website Superstation95.com was not scientifically sound or reality-based.

“It’s a lot of very complex equations thrown up on a piece of paper and then citing a bunch of organizations and scientists that I’ve never heard of,” Rangan said.

Rangan said county health officials are keeping an eye on radon levels. Radon is a radioactive gas formed underground by the decay of radium, and it has been linked to lung cancer in cases where it seeps up into living spaces and accumulates. The Public Health Department expressed concerns over an early plan by SoCalGas to dig 8,000 feet down, with the potential to release radon to the surface where workers might be exposed. In tests, the site was shown to have 1.7 picocuries per liter, which was not a hazardous level to workers in an outdoor environment, Rangan said. A level of 4 picocuries per liter concentration is potentially hazardous, he said.

He said no homes were at risk from radon.

What are the long-term health effects of the gas leak?

The Los Angeles County Department of Public Health says it doesn't have all the data and studies it would like to have to give a 100 percent guarantee that there are not any serious long term effects. But regional air regulators have ordered SoCalGas to pay for an independent study, so it's possible more information might emerge.

Are animals getting sick?

The Public Health Department visited 22 local veterinarian offices and several shelters in the Porter Ranch and surrounding areas and could not substantiate reports of widespread pet illnesses, health officer Jeffrey Gunzenhauser told the Board of Supervisors on Tuesday.

Must I leave my SoCalGas-paid relocation hotel or rental within 48 hours of the leak being plugged?

No. SoCalGas and the Los Angeles City Attorney announced an update this week to their previous agreement that residents would have 48 hours of continued housing relocation assistance after the leak is declared fixed. The new version gives residents eight days and seven nights of added time in their hotels and short-term rentals. The Los Angeles County Board of Supervisors on Tuesday called on SoCalGas to consider extending relocation assistance to 30 days.

SoCalGas says it will honor any longer-term leases they have entered into or agreed to reimburse, some of which extend to the end of March or later. About 1,700 relocated families have such longer-term leases.

The company will pay $500 in moving expenses to return families to their homes. It will also continue to pay mileage costs for parents who take their kids to the two LAUSD schools that were relocated outside Porter Ranch for the remainder of the school year.

Has there been a death from the Porter Ranch fumes?

An older woman who had previously been diagnosed with fourth stage lung cancer died. She had been functioning fairly normally for a few months after her diagnosis, but got sick after the leak began. The family has filed a wrongful death lawsuit naming SoCalGas, but the burden of proof might be very steep for the family given her underlying diagnosis.

Who's making robocalls to Porter Ranch families?

Residents relocated from their Porter Ranch and surrounding homes have been getting repeated calls from the same number, and when they answer, it turns out to be a questionnaire about the leak. It's unclear who is making the calls.

What's this leak costing SoCalGas?

As of Jan. 6, the company told shareholders they had spent $50 million. The company filed a cost breakdown with the California Public Utilities Commission. According to that document, the company had spent $23.6 million on relocations, $2 million on air quality testing and $1.4 million on public relations and communications.

Proposals from Gov. Jerry Brown and state legislators call for the cost to be borne by shareholders and not consumers, but that's not settled yet.

Will the region run out of gas or power this summer if Aliso Canyon closes?

Aliso Canyon's operations are near-stalled right now. It has been barred from injecting more gas since the leak began, and it won't be able to resume until a time-consuming set of safety tests is completed on the other 114 or so active gas wells there. The California Public Utilities Commission estimates it could be months before it starts operating normally. So, will we run out of gas?

Let's look at the numbers.

Normally the gas field can hold 86 billion cubic feet available for delivery to customers. The gas is held underground at very high pressure by these wells, which act like valves. Today, the field holds only 15 billion cubic feet of gas that could be shipped to customers, so the pressure is much lower. That's the lowest amount of gas that the CPUC estimates the gas company can keep underground and still serve the L.A. basin enough gas to heat on a streak of very cold days or serve L.A. Department of Water and Power's electric generating plants this summer on the hottest days.

If there demand spikes higher due to extended cold or hot weather, SoCalGas would have to curtail gas deliveries to outside customers, like LADWP's power plants, which has its gas delivered through SoCalGas pipes. The company is working the the CPUC and the California Independent System Operator to prioritize which LADWP plants would have first call on limited supplies of natural gas.