Wet weather is hampering the efforts of authorities to get to a derailed train in north west Queensland that crashed carrying almost a million litres of sulfuric acid, as drone footage reveals the scale of the situation.
Emergency services have been trying to reach the site near Julia Creek where the train left the tracks almost three days ago.
The train was carrying about 819,000 litres of sulfuric acid and there are fears that the highly toxic substance could have leaked into nearby waterways.
On Thursday afternoon, police said crews had finally reached the site and would start an assessment.
Police said water quality in Horse Creek was being affected by the leaked acid and because more rain was expected to fall the area would be treated with lime.
The Environment and Heritage Department says there's an "emerging concern about an increased adverse impact on the nearby Horse Creek".
The department is currently looking at strategies to neutralise the acid, and says it will use a helicopter and sandbags to deploy the lime.
The Flinders Highway remains closed in both directions between Julia Creek and Richmond as a result of flooding and the exclusion zone.
It is thought the exclusion zone will be in place through Thursday.