So you are suggesting that they do a full geotechnical...

So you are suggesting that they do a full geotechnical investigation and appraisal with all the surface and underground hydrological studies, geology, geotech and design work for every possible/conceivable design layout and then have them all Section 10'd at the eleventh hour by the minister? Thats not a really smart use of company resources.

You obviously don't know anything about complex projects because each different location for a possible tailings dam will also vary the location of the mill, waste rock dumps, environmental considerations of noise/dust/light/visual amenity, the surface infrastructure, powerline and road and water corridors and mandating no tailings dam means that the entire mining method and site layout is changed by going underground. What do you think the NSW regulators and other government offices would say if you gave them a proposal for hundreds of different site layouts? They would laugh you out of their office and tell you to come back with specific plans.

The federal minister's office didn't even know if the problem was a waste rock dump or a tailings dam on the day of the announcement. The decision's original justification was "Shh - its a secret."

I hate to break it to people but it's not a secret - it was a political decision based most likely on personal relationships between the objector and the minister or her friends (see sale of artworks to government agencies and politicians) and or a greens preference deal, not advice or objections from any professional state/federal assessment authority or the recognized native title group, who all had recommended that the proposal be approved or at the very least had no further objections.