These are valid criticisms and they should be addressed. I think the main issue is that this is urgent and we can't wait to do the amount of surveying or studying enough to guarantee a safe dumping. I'm just assuming here since no one said anything about that. But I think it's a valid assumption since the disaster is 12 years old. If they are rushing this after let's say 8 years of studying it, then whatever time they have left to fill up the tanks is probably not gonna be enough.

Every single decision we make is based on "current science" since we didn't invent a time machine just yet to look at the future. Just because science has messed up in the past, doesn't mean we should paralyze ourselves now.

What are these alternative treatments that the government rejected? How much more effective are they vs how much more do they cost? If treatment "A" gives us a 5% chance of a better outcome and costs 80% more, then it makes sense. If it was an 80% better outcome for 80% more cost then yeah they did mess up.