Report details project’s hazards
The U.S. Coast Guard and the U.S. Maritime Administration have identified several potential hazards of the proposed Port Dolphin Energy Liquefied Natural Gas Deepwater Port in its newly-released Draft Environmental Impact Statement.
Among the concerns are spills, explosions, increased water and air pollution and impacts on marine life, including fish, manatees, dolphins, whales and sea turtles.
Public comments will be accepted on the statement until June 2. A final version of the statement is due in mid-July, followed by a final public hearing later this summer.
In its two-volume statement, the Coast Guard identifies 11 potential scenarios in which liquid natural gas might accidentally be released into the environment: vessel collision, shipboard mechanical system failure, fire, gas release at processing equipment, severe weather, structural failure of the vessel, grounding, natural phenomena, mooring system failure, dropped objects and aviation accident.
Intentional attacks also were considered.
The worst industry accident listed in the report was in 1944 in Cleveland, where 128 people died after liquid natural gas leaked from a tank and formed a vapor cloud that surrounded streets and the storm sewer system, then ignited.
In 1973, 37 people died in Staten Island when the interior of an empty natural gas storage tank caught fire during repairs.
The most recent incident was in 2002, when a ship carrying liquid natural gas collided with a U.S. Navy nuclear-powered submarine, the U.S.S. Oklahoma City, causing a leak in the ship’s hull, but no injuries or deaths.
Overall, the report ranked liquid natural gas shipping as relatively safe.
"During the past 45 years, there have been approximately 100,000 liquid natural gas carrier voyages covering more than 235 million miles. There is no report of any accident involving a liquid natural gas carrier underway that has resulted in an unintentional release of liquid natural gas cargo. Over the life of the industry, 16 cargo transfer incidents worldwide have resulted in limited gas spills with some damage, but no cargo fires have occurred."
A spill of the supercooled liquid natural gas could freeze marine life in the water, but since liquid natural gas does not dissolve in water, the time frame would be limited to the period before the gas was boiled off, according to the statement.
Spills also could kill sea grass, which fish, manatees and sea turtles feed on.
"The industry is not without incidents, but it has maintained an enviable safety record," according to the statement. "Vapors are flammable only in concentrations of 5 to 15 percent natural gas when mixed with air. Liquid natural gas is neither flammable nor explosive. Natural gas will not explode in an unconfined environment."
"A combination of long- and short-term minor adverse impacts on water quality would be expected" due to sediment being stirred up during installation and operation of the port, according to the statement.
"During operations, cooling and ballast water discharges would have several impacts on water quality near the port, including increased water temperature, increased turbidity and decreased dissolved oxygen content. Spills of hazardous substances, such as hydrocarbons (e.g. petroleum, oils and lubricants), might result in short-term, minor adverse impacts on water quality."
"Short-term direct minor adverse impacts on air quality would be expected" from equipment during construction.
Emissions from ongoing port operations would have a "long-term direct minor adverse impact on air quality during the life of the project."
The product itself poses risks, too. "Since natural gas is a fossil fuel, combustion of natural gas contributes to the generation of greenhouse gasses."
"Minor to moderate short-term adverse impacts and minor long-term adverse impacts on biological resources could occur as a result of the project," including impacts on vegetation, wetlands and marine organisms.
A system that would take Gulf of Mexico water into the ship for cooling and expel hot water would adversely affect plankton, and could cause "direct, adverse, minor impacts on biological resources from the impingement or entrainment of marine organisms," including gag grouper.
In addition, 234 acres of bottom-dwelling benthic communities would experience "minor to moderate short-term and long-term adverse impacts" during construction.
"Benthic communities would be expected to recover quickly by recolonization from surrounding communities of similar organisms," according to the statement, but 66 acres of benthic substrata would be lost permanently.
The endangered smalltooth sawfish also could be affected.
"Increases in vessel traffic could increase the potential for collisions with federally listed marine mammals, thereby increasing the occurrence of serious injuries or mortality. The U.S. Fish and Wildlife Service has consistently concluded that a ‘take’ of a single manatee would jeopardize the continued existence of the species, and vessel collisions have been identified as a major source of mortality for this species."
The dolphins that the port is named for are listed as potentially impacted by collision, noise, entanglement and water turbidity as result of operations.
Dolphins would be able to outswim the seawater intake into the port’s cooling system, according to the statement.according to the statement.
Blue, sperm, fin, humpback and sei whales "have the potential to be affected by collision and noise anywhere on the high seas where they occur in these species’ habitats," according to the statement. They are all endangered species.
All five species of sea turtles that swim in Florida waters would be impacted – the threatened loggerhead and green and the endangered hawksbill, leatherback and Kemp’s ridley.
Lighting from the construction of the port could cause short-term, minor, direct, adverse effects on turtles, which are attracted to light, according to the statement, which adds that the port is eight miles farther from shore than humans or turtles can see at night, so lights would not disorient turtles hatching on shore.
Sea turtles, even hatchlings, would be able to outswim the seawater intake into the port’s cooling system, according to the statement, which lists other potential impacts on sea turtles such as collision, noise, entanglement, turbidity and consumption of marine construction debris.
The Audubon’s crested caracara, piping plover, wood stork and roseate terns are listed as possibly dwelling within several miles of the port.
The port, which would be within 93 miles of the Chassahowitzka National Wildlife Refuge and 152 miles from Everglades National Park, would cause "increases in vessel traffic, noise, marine debris and port lighting."
Geological resources (sand)
"Minor direct adverse impacts from port and offshore pipeline installation would be expected. Impacts would be localized and short-term. Subsea sediments are the primary geological resource that would be affected by the project. Approximately 50 acres onshore would be temporarily impacted by the pipeline right of way."
"Minor long-term impacts on commercial fishing, recreational fishing and boating could occur within the safety zone that would be established around the port. Commercial fishing would be temporarily excluded from the vicinity of construction activities for approximately 11 months during construction," potentially affecting 2,677 commercial vessels registered in Manatee, Pinellas and Hillsborough counties.
"Short- and long-term minor adverse impacts on recreational fishing, boating and other water dependent uses would result from construction and operation of the port due to visual impacts and restricted access within the safety zone."
Approximately 1,800 trips to and from shore are anticipated during the 11-month construction period. Operational activities are anticipated to generate approximately 938 trips annually.
"Offshore construction of the port would be visible to recreational boaters, residents and visitors."