The recent debate on these pages over the proposed trucking of liquified natural gas through Savannah is unfortunately typical of what passes for policy discussions these days, with competing interests making technically true but misleading statements.
The letter from Bruce Hughes of Southeast LNG on Sunday is an excellent example. As a scientist involved in energy and natural hazard research I feel compelled to dissect his letter in the hope of shedding a little light on this debate.
The claims by industry that LNG cannot burn or explode, and that when it evaporates it rises, are true. Yet they are also misleading.
Natural gas at ambient temperatures will rise, but LNG is extremely cold. Even as the liquid evaporates, the vapor is too cold to rise for some time and can travel for a significant distance over the ground before dissipating below dangerous levels. The radius of risk varies depending on weather and terrain, but can be several hundred feet for a truck accident.
While LNG may not explode in the conventional sense, it can undergo a process known as a rapid phase transition (RPT), which while physically a different process, has the destructive potential of an explosion. This process is triggered by contact with water - something we have in abundance along the route.
Of special concern is a truck running off the Truman Parkway and landing in the Casey Canal near Memorial Hospital. This could create a situation where a small leak results in an RPT event, catastrophically rupturing the container, and creating a cloud of cold gas.
Even a simple traffic accident could result in a pool fire, which would be a dangerous situation if it occurred near the hospitals. An LNG pool fire, while short lived, burns extremely hot - so hot it can cause burns and trigger secondary fires at a considerable distance from the fire itself. A pool fire in traffic would surely ignite adjacent vehicles and cause multiple severe burn injuries and fatalities.
The standard (and essentially only) practice for dealing with a pool fire is to let it burn itself out. Given that risk, I would not want these trucks passing closer than 1,000 feet to a hospital or other critical facility on a regular basis, certainly not in the volumes proposed by Southeast LNG, which would exceed two trucks an hour.
As to the repeated claim that LNG is "clean," while it may be true relative to coal, it is false overall. The LNG production and transport process is energy intensive, and the net impact on the environment per unit of energy produced by LNG is far greater than other energy sources, especially when compared to nuclear or renewables.
Mr. Hughes statement that LNG will "reduce our dependence on oil" is absolutely ridiculous, as we are simply exchanging dependence on foreign oil for dependence on foreign LNG, obtained from the same limited, unfriendly and politically unstable sources.
To be fair, the opponents of LNG often use fear-mongering and exaggeration in their efforts to stop LNG related facilities. The fact is, the risks of LNG are manageable, the environmental impacts no worse, and in some ways better, than comparable sources.
The industry has a fairly good safety record. But LNG does have risks, and natural gas in general is extremely problematic as a fuel, especially if one includes environmental and geopolitical considerations. My own view is that natural gas/LNG is not an appropriate fuel choice and its use should not be expanded, but we should make that decision based on facts, not on either the fears of opponents or the platitudes of industry.
As for the current debate, in my opinion the truck route as proposed is inappropriate, given the risks it presents to our critical lifeline infrastructure in the form of Memorial and Candler Hospitals. The Federal Energy Regulatory Commission should not approve it, and our elected officials should bring all of the pressure they can on Southeast LNG to change the route to avoid critical assets.
If it is approved, all the parties involved, especially the hospitals, must create realistic plans based on realistic scenarios to deal with a potential accident.
Chuck Watson lives in Savannah and runs Watson Technical Consulting, which performs risk assessments.
