The answer depends on whom you ask. For over a year, Puget Sound Energy has claimed that a 550-foot safety zone is all that is required. They say they have run the appropriate model to prove it. They say that the other information provided by anti-LNG activist claiming a 3.5-mile safety zone is false and not supported. There seems to be quite a discrepancy between the 550-foot claimed by PSE and the 3.5 miles (18,480 feet) claimed by the concerned citizens.
The PEAC-WMD model from AristaTek, used by the citizens, is used by nearly every large fire department in the United States. It is also used by the Department of Defense and all the U.S. Air Force bases in the world. It is supported by the Department of Homeland Security. They claim it is the “Gold Standard” because, “The integrated computational tools have expanded to include calculation of safe standoff distances from different types of hazardous events,…” The Tacoma Fire Department actually purchased this model, but even after many public requests, they have not felt the need to run it and confirm the 3.5-mile safety zone. It would cause too much conflict with the City of Tacoma’s stated position of supporting the LNG plant.
The absence of any official acknowledgement by the fire department has left the huge 3,360 percent disagreement in limbo. PSE continued to claim their modeling met all safety requirements. The citizens could only tout the quality of their data and the multiple agencies and organizations that recommended safety zones measured in miles instead of feet. It appeared to be a standoff, with PSE able to spend millions in advertising to assure the general public there was no danger.
The tiebreaker has now been found. A Public Disclosure Request (PDR) was made to the fire department and it was discovered that the Tacoma Fire Department had run a model to determine the safety zone. While they did not use the PEAC model, they used other similar models (ALOHA and CAMEO).
There was very little surprise when the fire department model showed a safety zone that extended more than one mile (about 10 times larger than the PSE model). Much like the model used by the citizens, it showed that the danger zone extended far beyond the LNG property lines. When the fire department ran the model on Tuesday, Nov 10, 2015 at 2:58 p.m., the danger zone had a 1.1-mile radius and had a perimeter of 3.51 miles. They also showed that 1,939 people and 693 housing units would be impacted. It would be a good assumption that if the wind were blowing in a different direction, the 1.1-mile safety zone would extend in any direction. Besides much of Northeast Tacoma, this would endanger most of the port and all the businesses and industries inside the safety zone.
There should be no doubt that there is a true danger in locating the LNG within the city limits. It endangers the port and the residents that are within the safety zone. While the numbers from the fire department and the citizens are not exactly the same, it does prove that the safety zone should be measured in miles not feet as proposed by PSE. The PDR request truly confirms what the concerned citizens have been worried about and what PSE has been afraid of revealing. It is too bad that the Tacoma Fire Department has failed to share this information since November 2015; they could have been a hero. To be fair, they have not yet issued their approval of the LNG plant. They are required to wait until PSE makes the official request. They still have time to protect the public from a catastrophic danger.
Steven Storms has a bachelors degree in Chemical Engineering (BSChE) and was a licensed Professional Engineer (PE). He had nearly 40 years experience working in heavy industry with a good portion in the energy and environmental fields. He retired as the project director of Process Evaluation. He is also past chairman of the Puget Sound chapter of the American Institute of Chemical Engineers (AIChE). Currently he is Vice President of ACT (Advocates for a Cleaner Tacoma), a member of Redefine Tacoma and a proud supporter of Native rights. He is a resident of Northeast Tacoma.