Porter Ranch Natural Gas Leak
Since the well began leaking Oct. 23, thousands of people in the Porter Ranch area say they have suffered headaches, nosebleeds, nausea and other symptoms from the escaping gas. The smell comes from an additive called mercaptan that is used to warn people of leaking natural gas, which is ordinarily odorless.
Southern California Gas Co. is paying to relocate those who say they are being sickened.
On Oct. 23, gas company employees noticed a leak out of the ground near a well called SS-25. It was late afternoon, so they decided to come back in the morning to fix it.
The next day, however, their efforts were unsuccessful. Gas was now billowing downhill into Porter Ranch, an upscale community on the northern edge of the San Fernando Valley. Customers were beginning to complain about the smell.
Gas leaks are not uncommon, and it took a couple weeks for this one to become news. When Anderle heard about it, in early November, she pulled up the well record on a state website. The file dates back to when the well was drilled in 1953. As she looked it over, she zeroed in on a piece of equipment 8,451 feet underground called a sub-surface safety valve.
If it were working properly, the gas company would be able to shut down the well. The fact that SoCalGas hadn’t meant, to her, that it must be broken. The records indicated that it had not been inspected since 1976.
SS-25 was cemented only from the bottom up to a depth of 6,600 feet. The rest — more than a mile of steel pipe — was left exposed to the rock formation. At the top, the 7-inch casing is surrounded by an 11¾-inch surface casing, which is cemented to the rock. But a new well also would have a layer of cement between those casings to provide greater strength and protection from corrosion.
Gas is now leaking through a hole in the 7-inch casing at 470 feet down to the bottom of the outer casing at 990 feet, and out through the rock to the surface.
The corporate culture of SoCalGas is nothing if not deliberate. And so, in 2014, the company proposed a methodical effort to check each well for corrosion. It would take about seven years and cost tens of millions of dollars. The plan was part of a request to the Public Utilities Commission to increase customers’ monthly gas bills by 5.5 percent. The alternative was to fix leaks only as they occurred, which one executive warned could be dangerous and lead to “major situational or media incidents.”
The SoCalGas plan went well beyond the requirements imposed by the state Division of Oil, Gas and Geothermic Resources, or DOGGR. Steve Bohlen, the outgoing head of DOGGR, has said several times that it does not appear that Southern California Gas violated any regulations.
Gas has now been spewing out of the ground at Aliso Canyon for two months. The gas company expects it to continue for up to another three months. Methane is a potent contributor to climate change. By one estimate, the leak is producing greenhouse gas emissions equivalent to the tailpipes of 2.3 million cars.
The Aliso Canyon leak has increased the state’s methane emissions by 21 percent. As of now, 2.3 percent of the state’s entire carbon footprint is coming from one hole in the ground above Porter Ranch.
“This is an environmental disaster,” said Mayor Eric Garcetti, who stopped by Porter Ranch Community School in November, just before flying to Paris for the United Nations climate change conference. “It’s devastating. It makes you question the long-term sustainability of a carbon-based power system.”
The local impact also has been severe. About 30,000 people live in Porter Ranch, a bedroom community of gated developments with 4,000-square-foot homes that sell for $1 million or more. The neighborhood offers good schools, clean air and a sense of security. All of that has been disrupted. Many residents have experienced headaches, nosebleeds, nausea or other symptoms. Some 2,000 families have been moved to hotels or short-term rentals to escape the gas.
Mercaptan
is also known as methanethiol and is a harmless but pungent-smelling gas which has been described as having the stench of rotting cabbages or smelly socks.
It is often added to natural gas, which is colourless and odourless, to make it easier to detect.
The gas is an organic substance, made of carbon, hydrogen and sulphur, and is found naturally in living organisms, including the human body where it is a waste product of normal metabolism. It is one of the chemicals responsible for the foul smell of bad breath and flatulence.
People who have eaten asparagus can experience the distinctive smell of mercaptan in their urine within 30 minutes of consuming the vegetable, which contains substances that are quickly broken down to methanethiol. However, not everyone is able to smell mercaptan in their urine as a genetic mutation in some people means they are immune to the odour.
The great advantage of mercaptan for industrial purposes is that it can be detected by most people in extremely small quantities, less than one part per million. This makes it an ideal additive to odourless gases, and, like natural gas, it is flammable.
What benzene is
- Benzene is a chemical that is a colorless or light yellow liquid at room temperature. It has a sweet odor and is highly flammable.
- Benzene evaporates into the air very quickly. Its vapor is heavier than air and may sink into low-lying areas.
- Benzene dissolves only slightly in water and will float on top of water.
Where benzene is found and how it is used
- Benzene is formed from both natural processes and human activities.
- Natural sources of benzene include volcanoes and forest fires. Benzene is also a natural part of crude oil, gasoline, and cigarette smoke.
- Benzene is widely used in the United States. It ranks in the top 20 chemicals for production volume.
- Some industries use benzene to make other chemicals that are used to make plastics, resins, and nylon and synthetic fibers. Benzene is also used to make some types of lubricants, rubbers, dyes, detergents, drugs, and pesticides.
How you could be exposed to benzene
- Outdoor air contains low levels of benzene from tobacco smoke, gas stations, motor vehicle exhaust, and industrial emissions.
- Indoor air generally contains levels of benzene higher than those in outdoor air. The benzene in indoor air comes from products that contain benzene such as glues, paints, furniture wax, and detergents.
- The air around hazardous waste sites or gas stations can contain higher levels of benzene than in other areas.
- Benzene leaks from underground storage tanks or from hazardous waste sites containing benzene can contaminate well water.
- People working in industries that make or use benzene may be exposed to the highest levels of it.
- A major source of benzene exposure is tobacco smoke.
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