Environmental testing done in the final days of the Montara oil disaster on the shores of islands in the Kimberley and along the mainland coast found no trace of oil in the sand or water, according to a new Environmental Protection Authority report.
Throughout the 10-week disaster, when more than 400 barrels a day gushed into the Timor Sea, there were fears that the oil had travelled 175km to the Kimberley.
But the EPA testing, carried out from October 27 to 31 last year, days before the oil rig was finally plugged, showed petroleum hydrocarbons were not detected in any of the water and shoreline sediment samples.
The 18 sites surveyed spanned from Camden Sound in the south to the Stewart Islands near Cape Londonderry in the north-east, with analysis of rock oyster and cultured pearl oyster tissue given the all clear.
In February, testing requested by Greens Senator Rachel Siewert showed that the spill's reach was bigger than previously thought and oil reached West Timor waters and fishing areas relied on by Indonesians.