Fears that land at the Dale Farm travellers site near Basildon is contaminated are to be investigated by the Environment Agency.
Basildon Council dug up part of the site to prevent travellers from staying there illegally. Before the travellers moved in, the area was used as a scrapyard.
Next week the Environment Agency will be carrying out extensive tests to see if the area is a danger to those living nearby.
Basildon Council says it's doing all it can to assist the Environment Agency but won't comment further at this stage.
The Travellers say they want the council to cover the area over again so their children can play in safety.