Avoiding Another San Bruno Explosion: How to Spot Early Warning Signs

by | Nov 4, 2010

In the wake of the tragic explosion that rocked San Bruno in September, authorities, utilities, and the general public are all asking two simple questions. Could this tragedy have been prevented? Could it happen to us next? The answer to both questions is a qualified yes. Which is precisely why we need to post haste build out a detection network designed to spot pipeline anomalies. Such a network could include in situ monitoring technology that would not only spot elevated levels of ambient natural gas that likely precedes any blast but also enable the utilities to quickly trace the source of that natural gas back to the leaking pipeline.

The cost of such a network would be small compared to the cost of another devastating blast. The bottom line is this: we as a society need to get into the field better technologies to spot potential problem areas quickly and affordably and to help trace problems back to the source pipelines in order to prevent blasts like the San Bruno fire — and to save lives. Such a system would also save utilities money both by preserving infrastructure and by conserving the expensive gas coursing through their pipelines. And technology to better detect and quantify natural gas leaks would also pay
huge benefits in terms of global warming. Methane, the key component of natural gas, is a greenhouse warming component roughly 25 times more powerful than CO2 and it likely has played a critical role in past global warming events.

In some sense, it is truly a miracle that a fire like this has not previously occurred. Problems with high-pressure pipelines are a well known phenomena that all too often have resulted in tragic explosions with loss of life. These accidents have, to date, primarily occurred on a smaller scale with far less loss of life. While state, local and federal government agencies have expressed grave concerns, the lack of an obvious catalyst like the San Bruno fire has made it difficult for utilities or governments to justify any costly and complicated effort to identify likely sources of pipeline
explosions. Such an environment, obviously, now exists and legislation demanding enhance monitoring technologies is moving through the U.S. Congress today.

America is crisscrossed by natural gas delivery pipes. That natural gas delivery system is rapidly aging. Many of the primary pipelines facilities were built decades ago with safety features and construction standards dating back to their original commissioning. Retrofitting all the pipelines sunk below thousands of miles of streets would be a monumental effort costing many billions of dollars in California alone. Shutting off these pipelines is simply not feasible. So, for now, the best option is detection of problems for rapid response and repairs. While utilities cannot predict exactly where and when a pipeline will rupture, they have designated which areas represent the highest risk (in fact, the San Bruno pipeline location where the blast occurred was designated as one of the riskiest).

That said, the inspection regime presently in place to monitor these areas is inadequate. The San Bruno location was last inspected in March 2010, six months ago. Laser spectroscopy-based technologies are in use right now by utilities and petrochemical plants to spot methane (the chemical that comprises natural gas) plumes with infrared detection. These handheld devices work quite well when they can be visually sighted at above-ground targets. However, without a very clear and defined target zone, visual inspection is not a good option. Further, visual tools cannot easily calculate exact changes in methane concentration in ambient air. And these cheap handheld methane guns most definitely cannot differentiate between isotopes of methane. Identifying isotopes of methane is important because each pipeline has a different ratio of methane isotopes – a bar code created by Mother Nature at the molecular level that is immutable and generally unique to a methane source.

Fortunately, more sophisticated technologies, can both detect elevation of methane on a wider-area level and differentiate isotopic methane signatures. This equipment can be mounted on trucks, in cars, and even in small planes to do surveys for methane emissions levels and mapping on a block-by-block level at normal driving or flying speeds. This type of mapping is exactly what would be useful in detecting elevated methane from unknown sources or flagging hot spots earlier. Such systems can quantify methane concentrations down to a parts-per-billion level, allowing for
earlier detection than with other technologies.

Likewise, these technologies could easily be built into 24/7 continuous monitoring stations near pipeline areas designated as being of the highest risk.

Mapping programs such as Google Earth could easily be overlaid with weather patterns to give residents an actual real-time, Internet accessible view of methane levels in their very own neighborhoods. For utilities, gaining the
capability to map escaped methane back to a specific block or a specific pipeline could prove invaluable. This capability might even allow them to identify leaky pipelines days or months earlier than they may be scheduled for maintenance. Those pipelines could be either shut down without disrupting the entire natural gas system or be quickly examined and, if necessary, repaired. Such technology is not cheap, to be sure. Each unit costs roughly the equivalent of a utility truck.  But such a solution is comparatively affordable considering the alternatives and the clear and
present danger from natural gas both to our immediate safety — not to mention to our planet’s environment — that is now all too obvious.

Michael Woelk is the CEO of Picarro, Inc., a maker of greenhouse gas detection and measurement equipment based in Sunnyvale whose customers include the National Oceanic and Atmospheric Administration, the Chinese Meteorological Administration, the World Meteorological Organization. and the California Air Resources Board.

Stay Informed

Get E+E Leader Articles delivered via Newsletter right to your inbox!

Share This