Igloo Moon
On 6 November 1996, the German gas tanker Igloo Moon ran aground outside Key Biscayne in South Florida. The vessel had a cargo of 6,589 tonnes of butadiene, which was compressed and liquefied. A chemical inhibitor was added to stabilise it.
The first step taken was lightering of the bunker oil. A plan for public evacuations was set up in case anything were to go wrong. Analyses were then conducted on the inhibitor and results showed only 20 days remained to recover the butadiene.
Because of the shallow depth, the Igloo Moon had to be lightered of its cargo in order to be refloated. A complete hydrographic survey of the area was conducted to find the best way to bring another gas tanker to recover the cargo. The ballast water was treated with 50 ppm of calcium hypochlorite for a six hour period in order to make it sterile for discharging at sea.
On 20 November, approximately 1,000 tonnes of butadiene was transferred onto the lightering vessel Selma Kosan to be sold in Houston. The day after, the Igloo Moon then released the ballast water and was refloated with the flood tide. The vessel finally sailed to Freeport in Bahamas.
Even though this accident was worrisome, no chemicals were released into the water.
Sources:
- HELCOM, 2002, HELCOM Response Manual - Volume 2