The EPA released its final decision report earlier this week, saying the project does not pose an unacceptable risk of impacts.
AWE and Beach Energy plan to build a new gas processing facility alongside eight production wells connected to the plant which will have a maximum export capacity of 250TJ/d.
The project will see the majority of gas from the deep conventional targets, the Kingia and High Cliff sandstones, developed and sent to the North West Shelf to be exported as LNG over a five-year period to backfill the declining facility and is the exception to the government's onshore export moratorium legislation.
Technically the molecules do not head north, but rather are subject to a gas-swap deal.
Environmental groups including 350 Perth, Lock the Gate and the Conservation Council for Western Australia have lodged multiple appeals against the project over potential fraccing, groundwater and emissions concerns.
There has been little indication from the project proponents they plan to frac the conventional project, though CCWA in the past has latched onto a 2015 release from AWE which suggested some unconventional upside.
AWE held the project before Mitsui bought it out in a bidding war. The 2015 statement was released before testing at Waitsia-4, which was so outstanding certifiers RISC increased the field's 2P reserves by 78%.
The activists suggested there were fundamental flaws in the bodys assessment and Mitsui's proposal was not consistent with EPA guidelines on greenhouse gas emissions.
The report noted greenhouse gas emissions were a key matter raised in submissions, saying the project must adhere to controls on the maximum amount of gas produced, and that the developer needs to implement a greenhouse gas emissions plan that "demonstrates the applicant's contribution to net zero carbon emissions by 2050".
However the report said the department would not assess or impose controls on emissions which are already regulated under Part IV of the EP Act.
"The delegated officer has therefore determined to exclude the assessment of GHG emissions from this application," it said.
Then environment minister Stephen Dawson signed off on the project earlier this year, saying "it is not possible to make a direct link between a single proposal's emissions and the environmental impacts associated with climate change in Western Australia".
The EPA said "It is also not the role of the delegated officer to reassess and determine the merits of an approval granted by the minister on the assessment by the EPA, or the enforceability or effectiveness of conditions within a Ministerial Statement".
It said the decision to approve the program was based on the project existing in an area that already had extensive oil and gas development.
It also noted AWE will implement engineering controls, which include elevating flare and exhaust emission points to facilitate air dispersion, the construction of containment ponds and implement drainage controls.
"The delegated officer is satisfied the above engineering controls lower the overall risk profile of the proposal and adequately address the concerns raised in public submissions regarding the risk of impacts to human health from air emissions and impacts to the Ejarno Spring and its catchment," it said.
350 Perth campaigner Anthony Collins told Energy News the decision to approve the program was disappointing but not surprising.
"Unfortunately this is what we have come to expect from a state government captured by gas lobbyists," he said.