A report by the Environment Agency, published today, details 13 breaches of the site licence by Waste Recycling Group including poor cover of the site, inadequate pest control and control of waste contaminated water.
But the agency says none of the breaches led to any pollution of the environment or harm to human health.
Paul Dainton, president of pressure group Residents Against Toxic Scheme (RATS), said: "Welbeck is the largest toxic tip in Europe, it does not just accept household waste and that is what makes it so frightening. It is the most dangerous threat to people's health that Wakefield has ever known.
"But if this report is to mean anything at all then the board members of the agency should meet the people who have to live near the tip and hear what they have to say."
The problems were identified by Environment Agency officers during a detailed audit inspection of Welbeck in July.
A separate agency report also published this week revealed increased levels of air-borne water particles from the green recycling site on Welbeck.
Mr Dainton added: "The levels of illness related to this kind of pollution is obvious to everyone who lives around the tip.
"There are major problems with Welbeck and these are only going to be solved by massive improvements in management which will only happen if the Environment Agency start policing the site properly."