The controversial $30 billion Woodside Petroleum's Kimberley liquefied natural gas (LNG) project in Western Australia won the nod of the state's Environmental Protection Authority (EPA) on Monday, leaving the WA environmental and federal approval as the only stumbling block for its realisation.

Once fully operational, the gas hub would facilitate the conversion of Woodside's and that of other gas producers' output into LNG for export to global markets.

The project gained controversy when WA Premier Colin Barnett declared some few months ago that his government would compulsorily acquire land for the gas station at James Price Point when negotiations between the Kimberley Land Council and natural owners collapsed and threatened its development.

As a common user hub, the Woodside gas precinct easily won the favour of the WA government, arguing that the facility provides "economic efficiencies to proponents, while reducing the development footprint compared to multiple, stand-along LNG processing plant."

In its released statement, the state government added that the gas hub "would also enable a coordinated and consistent approach to management of potential environmental, heritage and social impacts, monitoring of cumulative effects, and auditing of control mechanisms."

Also, Premier Barnett threw his support behind the project for its promised billion-dollar of business investments to Western Australia and the thousands of jobs set to be created by the gas station, which he said would directly benefit traditional and indigenous communities in the Kimberley region.

However, environmental groups raised their opposition on the gas project, citing that James Price Point's unique and pristine ecological system is too precious to be compromised for economic considerations.

The Wilderness Society told AAP on Monday that EPA's assessment report on Woodside's LNG project was incomplete and questions on marine waste discharge, oil spill modelling, marine primary producer habitat and coastal processes were glaringly left out by the report.

The group was also surprise to learn that the project gained approval despite alternatives offered and even preferred by the gas hub's joint partners, which included BHP Billiton, Chevron and Shell.

Yet Woodside had earlier declared that abandoning the project in lieu of other LNG processing proposals was economically unviable, despite pronouncements by BHP Billiton that it would refuse to be party on projects that run counter on the giant resource firm's values and standards.

Still, Woodside had insisted that the Kimberley LNG development project enjoys the backings of all its joint venture partners and following its EPA approval, the energy firm expressed confidence that a final investment should be forthcoming by the second half of 2012, barring of course anymore glitches with federal and environmental authorities.