The Western Australian Environmental Protection Authority granted approval yesterday. 

Environment minister Amber Jade Sanderson gave the tick for the nearshore components including a 32-inch carbon steel trunkline running 32 kilometres through state waters and the associated works to construct pipeline infrastructure.

"This is an important regulatory milestone as we now have both Commonwealth and State primary environmental approvals in place to support a final investment decision for the Scarborough development," Woodside's acting CEO Meg O'Neill said.

"Scarborough gas contains negligible reservoir carbon dioxide... combined with the adoption of best available proven technology in design at Pluto Train 2, these developments will be amongst the lowest-carbon LNG sources globally for Woodside's North Asian customers," she said.

Woodside said it has completed "extensive" stakeholder consultation on its nearshore proposal which included a four-week public review of its draft dredging and soil disposal management plan. 

All up, the WA EPA approved plan states a maximum of 2.8 million cubic metres will be dredged during trenching for the trunkline running over 400km from the field, and 1.6 million cubic metres will be in state waters.

"The volumes would be confirmed during detailed engineering design," the plan says. 

This follows acceptance of its offshore project proposal by the federal regulator in March last year. 

The company reiterated its plans for a final investment decision on the project in this half of the year. 

The decision to approve the near-shore pipeline was attacked by the Conservation Council of Western Australia, arguing it would damage nearby marine habitat and accelerate climate change.

"An independent technical review of the project found that the construction of the pipeline poses a high risk of injury and death to protected marine life including turtles, dolphins, and dugongs," CCWA director Piers Verstegen said.