Don't have any more information on the certificate nor do I know...

Don't have any more information on the certificate nor do I know what it means apart from what the submission mentioned.
All I know is that the ECNT raised this, which seemed to be outside what their usual area of concern (environmental vs permits/compliance).
IMO, an unusual thing for an enviro group to be concerned about.

However the time frame for this, what is required & the site selection process should be clarified by TNG.

Both are like first base checks - ie. before proceeding to any next step (announcements/CR/design/FEED/EIS preparation) do you have
- appropriate rights, ownership, paperwork etc to build an industrial facility at this site
- have you got the appropriate rights, permits, permission to undertake that type of operation at this site

If it is no to either of those, sort it out.

Stated simply, would you hire an architect & go to the bank to get a loan & put an application to council to build a house with out either of those things - ie. you don't own the block of land nor is the area zoned appropriately for the building you want.