should the tva have seen this coming? >> you know-- >> you were warned repeatedly. >> lesley, there were red flags that have been noticed all through the years, and we recognize that those red flags should have been addressed. but yes, we missed them, and we don't ever want to miss them again. >> the spilled ash is now being loaded onto trains and sent off to a dry landfill in alabama. right now, coal ash disposal is regulated by the states, some of which have strict rules, some hardly any at all. >> e.p.a. can be a force for good... >> lisa jackson heads the e.p.a. she's been reviewing whether the federal government should get involved by labeling coal ash a hazardous waste, which would mean much tighter regulations and oversight. why wouldn't you, right now, this minute, on 60 minutes, declare that coal ash is a hazardous waste? >> e.p.a., in making a regulatory determination, has to look at a number of factors, including the toxicity of the material and how it's currently managed. but that's done according to law. >> t