. >> before you became ceo, the exxon valdez was a national problem when it had this bill. what has exxon and other oil companies done to prevent that type of problem occurring in the future? >> the bell says -- the exxon valdez was an extraordinarily emotional event inside of exxon. what it motivated us to do was to completely change the way we deal with risk management. our that incidents -- out of that incident was an extraordinary effort to create what is called our operational integrity management system. at the time it was called something else, but it has evolved over the last 20 years. is a very detailed approach to how we manage all elements of risk in our business the world over. it is done the same way, no matter where you are. the benefit has been that as we moved people around the world from place to place or we go into any place, we take this system with us and do not have to create something from scratch. our people did not have to wonder how we will manage risk will we go from one part of the world to another. the execution of that system is what has changed.

. >> stahl: the spill was 100 times larger than the "exxon valdez," and it was all coal ash. >> roewer: you'd never heard of coal ash before kingston. >> stahl: never. >> roewer: never >> stahl: never. >> roewer: wasn't a problem. >> stahl: well, it was a problem, we just didn't know. the problem is, where do you put all that stuff? here, the tennessee valley authority, t.v.a., dumped up to 1,000 tons of coal ash every day into a wet pond near the plant, slowly amassing a waste-cake 60 feet high. some of the ingredients, according to the e.p.a.: arsenic, lead, mercury, selenium, cadmium, and other toxic metals. you know, some people say that this is a poisoned meadow. >> leo francendese: i guess that's one way to describe it. it just doesn't belong here. it needs to come out. >> stahl: leo francendese is an environmental "mr. fix-it." he was sent by the e.p.a. to clean up this mess. >> francendese: in the wrong circumstances, coal ash is dangerous. breathing it, that's dangerous. >> stahl: the summer heat can bake the ash into a fine talc- like powder that can wreak havoc on your lungs

before you ceo, the exxon valdez -- before you became ceo, the exxon valdez became a problem.our company and other companies done to prevent them from becoming a problem in the future? >> the exxon valdez was a national mistake tragedy, but it was also an extraordinarily emotional event inside exxon. i can tell you that because i lived through it. it motivated us to completely change the way we deal with risk-management. out of that incident was an extraordinary effort to create what is called today our operational integrity management system. at the time, it was called something else, but it has evolved over the last 20 years. it is a very detailed approach as to how we manage all the elements of risk in our business the world over. it is done the same way. it does not matter where you are. the benefit has been as we move people around the world from face to place, when we go into a new place, we take -- as we move people around the world from place to place, when we go into a new place, we have the same risk management from one part of the world to the next. that system has