Indicating the scale of the task to restore the site of last week's derailment, a train carrying 800 metres of rail line has made its way up from Port Augusta in South Australia.

The Australian Rail Track Corporation confirmed progress has been made towards the removal of the goods train which has remained in pieces at Nana Glen since last Thursday, with preparation for track repairs well underway.

A spokesperson for the ARTC said that would begin once the locomotives and wagons were clear.

"Our priority is to restore the rail line as safely and as quickly as possible.

"However, the time frame for the repair is dependent on weather and rain is forecast for coming days."

As of yesterday morning the two locomotives and 20 wagons, or carriages, which had remained on the track despite the derailment had been cleared.

Of the 16 wagons which derailed, five had been put back on the track and were awaiting removal.

The third locomotive, which derailed and spilled an estimated 11,000 litres of diesel, is now upright.

Equipment and materials needed to fix the line have either arrived or are en route to the site with around 1200 tonnes of ballast from local quarries on a train south of Coffs Harbour ready to be brought in.

The 800 metres of rail being transported by train from Port Augusta is expected imminently and a further 600 sleepers from Grafton are being steadily transported to the derailment site ready to be laid.

Early reports suggested a rail line wash out was responsible for the dramatic derailment, which occurred during a wild storm last Thursday morning.

Some of the detached wagons came to rest at Hill Top Farm Riding Centre, an equestrian centre on Morrows Rd.

Yesterday, the Environmental Protection Agency confirmed that test results carried out following the diesel spill had come back negative for oil and grease and it is understood the significant rain and flooding had lessened the potential impact.