In the US five years on federal and state officials are continuing attempts to determine the scope of damage to natural resources from the estimated 11 million gallons of oil spilled in 2005 during Hurricanes Katrina and Rita.
Since April 2010 Louisiana state officials have been negotiating with federal trustees over whether to use a state-proposed strategy that would determine the damage through a computer model that uses both the movement of water and information about potential effects to wildlife.
The assessment came to a halt when both state and federal officials involved were reassigned to conduct a similar investigation for the BP oil spills.
Federal and state officials say the delays in completing the Katrina-Rita spill assessment are the result of the complexity of the spills, which were caused by broken pipelines and failures in storage structures. Officials were more involved in assisting victims of the two hurricanes than in tracking the effects of the oil.
There were more than 540 individual spills, representing facilities owned or operated by at least 140 responsible parties.
The biggest issue slowing us down is the circumstances of the spills. They occurred during hurricanes and we dont know all the details of how the releases occurred, where the oil went, whether any damage was compounded by the hurricane, Tony Penn, Gulf branch chief for NOAAs Damage Assessment Center, explains.
Louisiana Oil Spill Coordinators Office (LOSCO) had only four employees until the BP spill, when the staff numbers were supplemented with workers from other state agencies.
The amount of oil released during Katrina and Rita is as much as was released during the Exxon Valdez spill in Alaska in 1989. By comparison an estimated 206 million gallons was released during this years BP incident in the Gulf of Mexico.
A lot of information has been gathered on a number of the larger spills, many of them along the Mississippi River, including several in Plaquemines Parish wetlands that have also been affected by the Deepwater Horizon spill.
According to a 2006 study on the larger Katrina and Rita releases for Oceanography magazine, the largest spill totalled 3.78 million gallons. It came from facilities operated by Bass Enterprises Production Company in Cox Bay. Another Bass Enterprises spill totaling 461,000 gallons occurred near Pointe a la Hache.
The second-largest spill, 1.05 million gallons, was from a broken pipeline owned by Shell Pipeline near Pilottown. Shell also was responsible for 13,440 gallons discharged near Nairn, also in Plaquemines. Chevron Oil is believed to have spilled 991,000 gallons near Empire and 53,000 gallons near Port Fourchon, while Venice Energy Services is believed responsible for the discharge of 840,000 gallons near Venice.