Methane Gas Leak In Southern California Forces Thousands To Evacuate Their Homes

The 2015 holiday season brought little cheer to the thousands of Southern California residents affected by a methane leak from an underground gas storage facility. Since late November, over 2,800 families from the Porter Ranch Community in Los Angeles have been forced to flee their homes to escape the adverse effects of the odorless gas. What's worse is that they have no idea when they will be able to return.

The gas leak, which is being called the largest environmental disaster in California's history, was first reported on October 23, 2015. However, it took the Southern California Gas Company (SoCal Gas) a few weeks to locate the damaged well in the Aliso Canyon, the largest natural gas storage facility in the Western United States. Also known as Standard Sesnon 25 (SS25) it is situated 8,748-feet below the ground, deep under a layer of nonporous rock that is normally very efficient at keeping the stored gas from escaping.

Since then, SoCal Gas engineers have been trying their best to stop the leak that they believe is coming from a pipe that lies 500-meters underground. Their first solution was to try plug the hole with a mixture of water, potassium chloride, and bentonite clay. Unfortunately, the injection was blocked at 470-feet by an ice cap, formed by underground water molecules bonding with the escaping methane.

Though the engineers managed to dissolve the ice with the help of ethylene glycol they soon encountered an even bigger hurdle. The upward pressure of the escaping gas was greater than that of the thick liquid they were inserting to seal the leak. After seven unsuccessful attempts they decided to abandon the plan for fear that it would rupture other pipes and result in an even bigger gas leak.

After much deliberation on December 4, the company experts came to the conclusion that the only way to solve the issue was by building a relief well to intersect SS25 at about 6,000-feet, well below the location of the current leak and divert the methane flow. This will help ease the gas pressure and enable them to seal the hole, initially with the brine and clay mixture, and then more permanently, with cement.

Though that sounds simple enough, it is not. That's because the engineers have to intercept the 7-inch pipe that lies a mile and a half below the ground at an angle without damaging other pipes in the vicinity. Not surprisingly, the well will not be ready until late February or mid-March. As a backup, the company also plans to start building a second relief well on January 20. Even if everything works according to plan, experts believe it will take between 6-8 months to resolve the situation.

While the utility is trying to reduce the emissions by extracting the gas at twice the normal rate, it is not enough. As of January 8, nearly 80,000 tons of the harmful greenhouse gas had escaped into the atmosphere. University of California, Davis, project scientist Stephen Conley who has been monitoring the leak says the number effectively doubles the emission rate for the entire Los Angeles basin for the year.

This is extremely worrisome to environmentalists. That's because methane is 25 times more efficient at trapping heat in the Earth's atmosphere than carbon dioxide. It is also highly explosive, leading to fears that accumulation of the gas could trigger dangerous explosions.

Though the odorless gas, which is the the main constituent of the natural gas that is used for heating and cooking is not poisonous, the chemicals added to smell a gas leak are known to cause nausea, headaches and even nosebleeds - All symptoms experienced by the residents of the Porter Ranch community before being evacuated.

On Jan 8, Jerry Brown, the Governor of California declared a State of Emergency and ordered the utility to stop any further gas injections into the leaking storage facility. He also asked them to provide test results and daily updates as well as come up with alternative solutions in case the current efforts fail. Hopefully, the relief well will work as anticipated, allowing the residents to return to their homes soon.

Resources: Latimes.com,scientificamerican.com,extremetech.com,insideclimatenews.org,bbc.com