For the past year local air regulators have been tracking the chemicals companies use in oil and gas exploration around Southern California. In a report released Wednesday, four environmental groups crunched the tracking reports to find that more than 40 toxic chemicals have been used in dozens of drilling operations, often near homes, schools, and hospitals.
The South Coast Air Quality Management District has sought information about so-called "well stimulation" activities. This includes hydraulic fracturing or “fracking” and also processes known as "acidization" and "gravel packing." The methods differ slightly, but all seek to inject material into fissures in the earth in order to extract hard-to-reach oil and gas.
The top chemicals used during the past year include crystalline silica, methanol, hydrofluoric acid, and formaldehyde.
Crystalline silica is a cement additive also known as “frac sand.” It's used to hold open cracks in underground rock formation so that gas and oil can travel into the well. While crystalline silica is naturally-occurring, respiration of the fine sand can cause silicosis, an incurable lung disease.
Methanol is a volatile gas, with wide-ranging health effects from exposure.
“One of the interesting things about something like methanol is you can see immediate harms like burning of the eyes or stomach problems,” said Angela Johnson Meszaros, general counsel for the Physicians for Social Responsibility of Los Angeles. Her group was among those that surveyed AQMD tracking reports. “You can also see long term problems like problems with the nervous system, headaches and the like. And you can also see reproductive harm and harm in the next generation.”
The report also helps fill in a sometimes-sketchy picture of oil and gas production in southern California’s highly populated urban core, and reveals the extraction techniques preferred over the past year.
Just 14 of the drilling events reported by companies to the AQMD under this requirement were fracking. “There’s not a lot of fracking happening in southern California,” says Johnson Meszaros. “What’s really happening here is acidization.”
More than 300 of the events reported were acidization events, in which acid is mixed with other chemicals, water, and sand in order to create tunnels in rock through which oil and gas can flow. Hydrofluoric acid is used for this purpose.
AQMD spokesman Sam Atwood says regulators are gathering tracking data for up to two years as part of the initial phase of its disclosure rule. In the second phase, regulators then will be “evaluating if there are significant air impacts and if so proposing regulations to address those impacts.”
There are no indications at this point that any chemicals identified by the companies to the AQMD have exposed anyone to unhealthful levels of toxic substances.
In an e-mail, Colin Maynard with the Western States Petroleum Association said that oil and gas production has occurred in Southern California for close to a century. “That production takes place day in and day out in the most heavily regulated environment in the world, and it takes place without harm to the environment or communities,” he wrote.