The issue goes back to the early 1980s when the then Rhondda Borough Council gave itself planning permission to open the site.

The people of Rhondda want to know who is accountable for the disaster which is Nantygwyddon tip

Geraint Davies AM

In a leaked draft report, investigator David Purchon describes the choice of the Nantygwyddon site as extraordinary.

He claims the location is too wet, too windy and too near to homes.

The report argues that household waste disposal at the site should stop and there should be thorough pollution monitoring.

It said the site was perceived as a nuisance to local people in 1995, when it added to fears about congenital health defects.

Mr Purchon believes there should be specific health studies into this area with independent expert advice.

The report also criticises Rhondda Cynon Taff council, saying it lacked the will and mechanisms to control the company that was running the site.

Natalie Medlicott and daughter Harriet

Copies of the report were delivered to residents near the site on Thursday morning.

They have until January to respond to the document which will be debated by the assembly in the spring.

Geraint Davies, Plaid Cymru AM for Rhondda, said: "The people of Rhondda have been waiting for answers about Nantygwyddon tip for a very long time.

"They want to know all that has happened, why it was chosen in the first place, the design, the construction and the management.

"And they want to know who is responsible and who is accountable for the disaster which is Nantygwyddon tip."

Resident Ron Davey said: "We would like to see the tip closed today.

"Everybody is recycling and they should stop the industrial waste going up there while it's still open.

Natalie Medlicott believes her six-year-old daughter, Harriet, who was born with a rare stomach condition and has undergone three operations, was damaged by the tip.

Rare condition

Two years after Harriet was born, another child in the same village - which is just a mile from the Nantygwyddon landfill site - was diagnosed with the same condition.

The site is now run by a company called Amgen Rhondda Limited.

All Amgen shares are held by Rhondda Cynon Taff County Borough Council.

The local authority's new waste strategy foresees the total closure of the site within three years.

That would be achieved by recycling on an ambitious scale and by bringing to an end the importation of waste from other local authorities.

Councillor Syd Morgan said the authority would probably prefer to close the site as soon as possible.

He said: "We can only do that when all the refuse throughout Rhondda Cynon Taff is being recycled."