Dredge spoil will still be dumped within the reef’s marine park under a plan to expand a Queensland coal port, but other options are being explored.

A port authority carrying out a major dredging project to expand a Queensland coal port isn’t abandoning plans to dump the material in the Great Barrier Reef marine park.

But North Queensland Bulk Ports (NQBP) says it is looking at alternatives – including dumping the three million cubic metres of seabed spoil onshore – to ensure the expansion of Abbot Point goes ahead.

“Offshore disposal has not been abandoned,” a NQBP spokeswoman said in a statement to AAP.

“It is true, however, that in view of court proceedings we are continuing to review all options with regards to Abbot Point.”

She was referring to a legal challenge by the North Queensland Conservation Council against the decision to approve dumping spoil within the marine park.

Court proceedings could hold up the project by up to two years, giving proponents GVK Hancock and Adani incentive to investigate alternative dumping options.

It was hoped the dredging project, which is being managed by NQBP on behalf of the mining companies, would begin in June.

The NQBP spokeswoman said the company “stood by the science”, which she said showed offshore dumping was the least environmentally damaging option.

Federal Environment Minister Greg Hunt, who last year approved the port expansion and dredging project, has said NQBP may submit a new plan to dispose of the material on land, and if they do, he’ll consider it.

“I can’t put a time frame. It may be a month, it may be less, it may not occur,” Mr Hunt told ABC radio.

“But we have encouraged and invited (another option).

“There is an emerging option, which I’ve said we’d welcome and consider on its merits.”

However, NQBP has said it isn’t preparing to resubmit a proposal but said the company wouldn’t rule out doing so down the track.

Environmental groups reacted cautiously to reports alternative land dumping sites were being considered.

Both Greenpeace and WWF Australia said it was encouraging that NQBP were looking at other options.

But they say the dredging project may harm the reef, whether spoil is dumped on the land or at sea.

Greenpeace spokesman Adam Walters said the port expansion and associated dredging would create damaging dredge plumes, destroy seagrass and boost shipping across the reef.

He called on Mr Hunt to scrap the dredge project altogether.

WWF Australia spokeswoman Louise Matthiesson said North Queensland Bulk Ports should take another look at a proposal to build a much longer jetty rather than carry out dredging so ships can access the port.

“We remain concerned the dredging itself would also damage the World Heritage area,” she told AAP.

“We’ve been encouraging North Queensland Bulk Ports to go back to the drawing board.”