Rely on Thermal Energy Even After a 500-Year 9.0 Earthquake

Washington ranks 50th among all the states and the District of Columbia when it comes to being ready should a disaster strike, according to American College of Emergency Physicians as reported in The Seattle Times (Jan. 16, 2014). As bleak as those findings are, a national firm that studies how well regions and companies are ready for earthquakes found that one local utility could continue to operate after a 500-year quake and likely a 2,500-year event, too.

That utility is Seattle Steam, which provides steam for heat and equipment sterilization to Harborview, Swedish and Virginia Mason hospitals. In the event of a major quake, hospitals would quickly fill with the injured at a time when their resources would be stretched. Being able to sterilize tools and equipment would be essential.

Steam utilities today have come a long way from what they were in our grandparents' day, though the basic concept is the same: a centralized boiler generates steam that it delivers through a network of pipes. Today's steam systems are highly energy efficient, burn carbon-neutral biomass fuel and use state of the art equipment and piping.

In a report released late last year, Ballantyne Consulting studied Seattle Steam, a privately-owned district energy system that serves about 200 buildings in downtown Seattle and on First Hill. Ballantyne found that Seattle Steam's generating facilities and network of largely buried pipes would be highly resilient to a major earthquake. The benchmarks Ballantyne used were a 500-year quake, as well as a 2,500-year event. This meant they considered earthquakes up to 9.0 magnitude, as well as those that would shake for up to three minutes. A 9.0 quake last struck Seattle in 1700. The Nisqually Earthquake in 2001 shook for about 45 seconds and registered 6.8 magnitude and caused little damage and did not interrupt steam service.

Ballantyne examined Seattle Steams two generating plants, as well as its 18 miles of piping. They searched for potential failure points given the likely scenarios of 500-year and 2,500-year earthquakes. It studied the effects of prolonged shaking, likely liquefaction and permanent ground movement. They found that in the 13 years since the Nisqually quake, Seattle Steam had taken a variety of steps to make its system even more resilient. Even with a complete power failure, as well as interrupted gas and water supply — the three things the utility needs to generate steam — Seattle Steam had installed back-up generators, added fuel storage and dug its own deep-water well. It had also upgraded much of its delivery system of underground pipes, making them highly resilient to shaking, ground liquefaction and permanent earth movements. It's technology would now allow it to quickly bypass problem areas.

"The modern high pressure distribution system serving the hospitals should have minimal damage and be operable immediate or within hours after the event," the Ballantyne report said of Seattle Steam's system. "...Localized settlement of soils could cause failures in service connections. With the redundancy provided by the looped system, even several pipe failures could be quickly isolated and service quickly restored to critical customers."

energy systems like Seattle Steam have a great track record of withstanding quakes. In fact, Seattle Steam remained in service with no downtime during the Nisqually earthquake. The same was true of the district energy system in San Francisco during that city's 1989 earthquake: There was no interruption in steam service.

District energy systems have performed well in other disasters, as well. When Superstorm Sandy struck the Eastern Seaboard in 2012, other utility systems failed. Areas served by district energy systems like Seattle Steam fared much better. In New Jersey, for instance, Princeton University, which relies largely on a steam energy system, was able to provide heat and power to the entire campus without missing a beat. In storm-ravaged Long Island, Nassau Energy Corp. never lost service to any major customers. Nassau Energy was able to supply thermal energy to a 530-bed medical center and even the evacuation center itself.

The American College of Emergency Physicians warnings about our region's readiness raises serious questions that must be addressed. Our community can take some solace, though, in knowing that three of our most important hospitals, including the region's only Level One trauma center, would continue to get the thermal energy they depend on even after a 9.0 quake.

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