Of the nation's 240,000 miles of gathering lines, only about 10 percent are regulated. When leaks or accidents occur on the remaining 90 percent, operators aren't required to notify regulators. In most cases, state and federal officials don’t even know where these lines are located.
Pipeline accidents involving natural gas are among the most feared industry accidents, because gas is so explosive. When a poorly maintained natural gas distribution pipeline exploded in San Bruno, CA. in 2010, eight people died and 38 homes were destroyed.
To try to prevent such tragedies, the federal Pipeline Hazardous Materials Safety Administration (PHMSA) has traditionally focused on regulating transmission lines, which carry gas to refineries, and distribution lines, which carry gas to businesses and homes. Until the early 2000s, that approach seemed to make sense.
Earlier gathering lines were much smaller and operated at far lower pressures than transmission and distribution lines. Most were also in rural areas, where mishaps would be less likely to cause widespread damage or loss of life. But the technology that triggered the U.S. drilling boom—hydraulic fracturing, or fracking—has changed that equation. To accommodate the volume and pressure of the gas coming out of fracked wells, gathering lines are now 12 to 36 inches in diameter, instead of 2 to 12 inches. They operate at much higher pressures, too.
By 2020, the number of miles of gathering lines is expected to almost double, to
If more than 10 buildings are within 220 yards of a line, the gathering line must be regulated. If the buildings are outside the 220-yard radius, the line is not regulated.
Operators of regulated lines must give state or federal regulators details about their operations, including pipeline diameter, exact location and maximum operating pressure. They must also inspect and maintain their lines and report details of any accidents, including fatalities, injuries and property damages.
None of these fundamental practices are followed with unregulated pipelines.
Because PHMSA doesn't collect data about rural gathering lines, it's difficult to estimate how much damage they cause each year. In 2010, accidents on regulated gathering lines caused more than $15 million in property damage, or approximately $1.8 million per incident according to the GAO report.
In the past, gathering lines operated at pressures of between 5 and 800 pounds per square inch, according to the GAO. But the pressures increased when drilling companies began switching from traditional drilling techniques to hydraulic fracturing, which allows them to extract small molecules of gas trapped in shale rocks. During fracking, a mixture of water, sand and chemicals is sent into the earth at a very high pressure in order to break up the rocks and release the gas. The gas is then discharged into the gathering lines at a similarly elevated pressure.
Last year Ohio passed an energy bill that included regulations for rural gathering lines. This year Texas passed similar legislation. In Texas, the state's Railroad Commission now has authority to regulate more than 154,000 miles of unregulated gas and liquid gathering lines. The Commission will begin evaluating the best way to move forward with determining the risks these facilities present to the public. Inspections will begin on September 1, 2015. (Inside Climate News, 9/26/2013)