MONTARA WELL HEAD PLATFORM OIL LEAK UPDATE

29 August 2009

The Australian Maritime Safety Authority surveillance aircraft conducted its daily flight over the scene of the Montara Well Head Platform oil leak today.

Data from the flight reveals that the slick coversa rectangular area approximately15nautical miles (nm) to the north of the Montara Well Head Platform and 60 nm to the east of the rig.Only 25% of thisareais affected by the leakconsistingofstreaks of oil and patches of sheen.The heavier concentrations of oil surround the rig out to a distance of 3nm.

The nearest point to the Australian coast is in excess of 80 nm.

The size of the oil slick was confirmed today (Saturday).

The National Plan aerial observers are trained and experienced in observing oil on the water, to recognise best practice and follow internationally recognised procedures. The search altitude for observation is determined by the visibility prevailing.In clear weather, the optimal altitude for observers is 1,000 to 1,500 feet.However, it is necessary to drop to half this height (500 to 750 feet) be able to confirm the effectiveness of dispersant on the oil.

Earlier estimates of the oil slick have been made by experts employed by AMSA - the agency responsible for the clean up. The estimates have guided the clean up work, including the use of dispersants to break up the oil.

AMSA conducts training courses in aerial observations for their own staff as well as other Agencies that are involved in this type of work. It is notoriously difficult to distinguish between oil and a variety of other unrelated phenomena such as: cloud shadows, ripples on the sea surface, differences in the colour of two adjacent water masses, suspended sediment, floating or suspended organic matter, floating seaweed, algal/plankton blooms.

Haze and light reflection off the sea affects the visibility of oil. In very calm conditions the sea has a very glassy appearance which often is mistaken for oil.

The spraying of dispersants enhances the breaking up the oil which then forms sheen on the water. That sheen eventually breaks up with the natural movement of the water, sunlight and evaporation.

AMSA remains focused on the priority of combating the oil leak.

Media inquiries:Mick Spinks0417 615 769

Photo shows dispersion of oil has occurred from the first run.
Aerial dispersant spraying is continuing.