Deepwater Horizon Incident Declared Spill of National Significance; Attempts to Apply Dispersants at Source 1,500 Meters Below Surface

Deepwater Horizon trajectory map 30 April. Click to enlarge.

The Obama Administration has declared the Deepwater Horizon incident a Spill of National Significance (SONS). A SONS is defined as “a spill that, due to its severity, size, location, actual or potential impact on the public health and welfare or the environment, or the necessary response effort, is so complex that it requires extraordinary coordination of federal, state, local, and responsible party resources to contain and clean up the discharge” and allows greater federal involvement.

Estimates of the release rate increased to 5,000 barrels (210,000 gallons) per day based on surface observations and reports of a newly discovered leak in the damaged piping on the sea floor. (Earlier post.) Projections are that the oil slick will reach Louisiana shoreline areas today.

IXTOC I: 3 Jun 1979 to 23 Mar 1980
On June 3, 1979, the 2-mile deep exploratory well, IXTOC I, blew out in the Bahia de Campeche, 600 miles south of Texas in the Gulf of Mexico. The IXTOC I was being drilled by the SEDCO 135, a semi-submersible platform on lease to Petroleos Mexicanos (PEMEX).
The oil and gas blowing out of the well ignited, causing the platform to catch fire. The burning platform collapsed into the wellhead area hindering any immediate attempts to control the blowout.
The well began spilling oil at a rate of 10,000 to 30,000 barrels per day. By the time the well was brought under control in 1980, an estimated 140 million gallons of oil had spilled into the bay.
IXTOC I well blowout. Click to enlarge.
Although the response team was eventually able to activate the BOP, the pressure of the hydrocarbons began rupturing the valves, and the BOP was reopened. Two relief wells were eventually drilled to relieve pressure and allow the capping of the well on 23 March 1980.
The IXTOC I incident is currently #2 on the all-time list of largest oil spills of all-time, eclipsed only by the deliberate release of oil, from many different sources, during the 1991 Gulf War.

The National Oceanic and Atmospheric Administration (NOAA) is assisting the Unified Command in evaluating a new technique to apply dispersants to oil at the source 5,000 feet (1,524 meters) below the surface. If successful, this would keep plumes and sheens from forming