Travellers who had occupied an empty car park have been escorted off the site by police.
Around ten travellers set up camp on the former Elstree Business Centre car park in Rowley Lane more than two weeks ago, and more arrived over the course of the fortnight.
They left the site at midday today under the supervision of High Court enforcement officers, Borehamwood Police and the council's environmental health team.
They were shadowed by police on the M25 until they left Hertfordshire.
The travellers left behind 75 piles of mixed builders waste, several empty propane bottles, and one caravan.
A council spokeswoman said nothing hazardous was found
She added: "There is very little domestic waste as it appears they were burning it. The remaining waste is unlikely to be attractive to vermin and the only danger to the public would come from broken glass and other sharp objects if they trespassed."
A spokeswoman for landlords Legal and General said the clean-up operation would begin tomorrow.
She added: "We have done as we promised to get the travellers off the site as quickly as possible."