The safety studies of potential spills, leaks and fires at Puget Sound Energy’s proposed Tacoma Tideflats liquid natural gas plant appear to back up the company’s contention the hazards wouldn’t reach across the site’s property lines.
Records obtained by The News Tribune — including a plant siting study, a fire protection evaluation and a series of video models of plant accidents — contemplate incidents from bad to worse as part of explaining the potential risks of building the plant. PSE has fought public disclosure of the documents.
Among the scenarios envisioned in them: a leak in the natural gas pipeline that feeds the $275 million plant or a rupture and fire at the top of the storage tank that will hold 8 million gallons of liquid natural gas, or LNG.
Such a fire couldn’t be extinguished and would have to burn itself out while the facility is evacuated, say the studies, which were paid for by PSE and conducted by a pair of European firms.
As for a large-scale leak, analysts estimated it could flow up to 10 minutes before the source is shut off, automatically or by hand. Concrete curbs and other containment structures would contain the LNG in pools, where it would evaporate as it warms, the analysis says.
“Because of its narrow flammability range,” the fire protection evaluation states, “unconfined clouds of natural gas generated by an outdoor leak or liquified natural gas spill present little danger of explosion.”
The records are among volumes of paperwork generated so permits can be issued for PSE’s 30-acre LNG plant, which is scheduled to open in 2019 at the Port of Tacoma.
Although they contain no indications the facility constitutes a potential disaster for the broader city, they have become the most controversial records attached to the project.
The studies were performed by Chicago Bridge & Iron, an engineering conglomerate based in the Netherlands, and its subcontractor Gexcon, a Norway-based fire and gas explosion safety company.
They consist of:
▪ A 144-page siting study that examines how the plant would weather a series of possible disasters.
It factors in gas volumes, wind speed, the rate at which LNG would evaporate into natural gas and how quickly a gas cloud would disperse to nonflammable levels. It inventories the hazardous material and other risks on the plant site.
One item is a 173-item analysis of every pipe larger than 2 inches in diameter in the plans, including the likelihood of each breaking and how bad the problem could be.
▪ A 44-page fire protection evaluation of how to prepare the Tacoma Fire Department and other agencies to combat a fire that breaks out at the plant. Because water would only make an LNG fire worse, the plant is to be equipped with at least nine industrial-size dry chemical fire extinguisher installations.
▪ Ten computer-generated videos showing how gas vapors would emanate from various aspects of the plant in various incidents.
In one of the most complex and problematic situations examined in the studies, a flammable vapor cloud from one set of pipes could grow past the plant’s property line and get close to East 11th Street. An 8-foot-tall vapor barrier — whose design in the documents is described as “based on typical slatted chain link fencing” — would keep the cloud contained, according to the study.
Another 10-foot-tall vapor barrier is mentioned as planned for the Totem Ocean Trailer Express dock where the LNG will be piped for use as ship fuel.
PSE spokesman H. Grant Ringel, notified Wednesday that the newspaper had a copy of the records, said that the studies had not resulted in any large changes to the plant’s design.
“Adjustments were made along the way, but not anything massive or major,” Ringel said.
He declined further comment about the documents.
On its website to explain the project, PSE describes its safety studies without presenting them. The site’s questions-and-answers page says analysis of “all possible leak, spill, fire and explosion scenarios” proved any facility accident would be contained on PSE’s property.
“We conducted nearly 200 possible failure scenarios, and the proposed facility passed them all,” the PSE website says. “If it didn’t, we would have to redesign it until it did.”
PSE has gone to court three times to stop the safety studies from becoming public, via lawsuits against people who requested the documents as public records of the city and state agencies they were filed with.
One of those lawsuits is against The News Tribune and the reporter who requested the documents.
In its court filings, PSE has said the safety studies cannot be released because of federal law protecting sensitive infrastructure from potential terrorist attacks. Two Pierce County Superior Court judges have rejected the argument, which PSE is now making before the Washington State Court of Appeals to keep the records secret. The city of Tacoma, the reports’ official custodian, has not fought their disclosure as public records.
While those appeals are pending, PSE has discussed in several venues releasing the records under conditions that would shield much of their contents from public discussion.
On Sept. 14, a spokesman for the utility company offered The News Tribune a set of documents, but asked editors to sign a non-disclosure agreement to restrict how they might be shared.
The newspaper declined the offer.
On Sept. 15, PSE officials said at a Port of Tacoma meeting that some safety studies will be made available to the public and media at a PSE facility — with the requirement of signing nondisclosure papers — in coming days.
The News Tribune has independently obtained a copy of the records.
“We’ve always believed these were public documents,” said Karen Peterson, the newspaper’s executive editor. “Two judges and the city of Tacoma do, as well. This information needs to be part of a fulsome and public conversation about the safety of this plant. And that needs to happen before the plant is built.”
In court seeking the studies’ release, Michele Earl-Hubbard, attorney for The News Tribune, said PSE appeared to be taking as much time as possible in contesting the documents’ release in court while it continues pushing to get construction permits for the building.
Superior Court Judge Frank Cuthbertson, who heard the newspaper’s case and reviewed the documents privately, said in court in August that the records issue “needs to be resolved sooner rather than later” to inform considerations over whether the plant should be built.
“If the public needs to know and needs this information, it needs to get out there,” Cuthbertson said.
Appeals Commissioner Eric B. Schmidt issued a ruling Sept. 9 that barred the city from fulfilling the records request of The News Tribune until the appeal is considered in December. The commissioner also rejected a request by the newspaper to pause work on permitting and site-clearing until the records were released.
The newspaper was not placed under any restriction in Schmidt’s order.