National Assembly water and environmental affairs committee chairman Johnny de Lange on Tuesday warned mining companies they could not simply absolve themselves of responsibility for acid mine drainage (AMD).

The committee is currently holding public hearings on the AMD problem in the Witwatersrand, where AMD has already been decanting in the Western Basin since 2002.

Rand Uranium CEO John Munro told the committee the seriousness of the problem had been recognised long ago and it was becoming clear it was a "legacy issue".

"And spending all our time finding culprits may well be a waste of resources," he said, adding that there were new operators in the area.

"They simply could not have created this problem. As a result, burdening these new companies with the sins of the past is simply unsustainable. These companies will collapse."

It would be very hard to find the "culprits" responsible for the problem.

He said it was more than likely that they were all gone and that the companies no longer existed.

"And even if you can find some companies you'll never hold them accountable because of the complexity of acid mine drainage and how underground mining works and how the AMD actually is created."

The industry believed the best solution to the problem was to find an economically viable solution, he said. AMD could be turned into potable water.

After sewage, AMD was the next best source of potable water.

"From our point of view, it is all about action as opposed to examining about what happened over the past 100 years, which we believe will be fruitless," Munro said.

De Lange responded: "I think you guys must not be so cavalier about the ownerlessness. It may not necessarily be the most practical approach, but people want to see who the culprit is.

"It may very well be that litigation hasn't succeeded against you because maybe the litigation that has been brought has been quite pathetic. Maybe if you get a real firm of lawyers to actually tackle this issue and put all the nexus and evidence together."

New mines started under the new environmental laws knew very well there was "water down there" when they bought the mines and could not deny responsibility to deal with it.

The problem had to be dealt with in a civil manner in a practical way, he said.

Also worrying was that the proposed solution gave mining companies no responsibility in any capacity.

"There's no doubt that if of course we can get an economically viable solution to the problem... we mustn't see this necessarily as a problem, but as an opportunity in a water scarce country.

"So we agree with that approach, but the problem is the mines can't be completely out of this in the end and we just give the problem to someone else," De Lange said.

Munro said companies were taking action on the basis that they believed "someone has to do something" and that would continue to be the industry's attitude.

"If we believed it was just an ownerless thing, and really I would like to emphasise that we're not cavalier about it, if that was the case we wouldn't be spending R2.5-million a month or some 25% of our executives' time on lobbying to find a solution.

"So it's not a question of really dismissing the question of liability and apportionment. It's a question of what can we do proactively going forward and I echo the chairman's sentiments about doing that," he said.