Waste firm Veolia applied to Hertfordshire County Council to build an energy recovery facility to treat municipal, commercial and industrial waste plus the importation, storage and transfer of council-collected healthcare waste.
The proposed plant, in Hoddesdon, Broxbourne, would have a maximum capacity to accept around 350,000 tonnes per annum of waste.
The county council resolved to grant permission in December 2017 but the application was subsequently called in by the secretary of state.
Inspector Jennifer Vyse had recommended that waste firm Veolia be granted permission for the plant on land at Ratty’s Lane, Hoddesdon.
Vyse had concluded that the "urgent and pressing need" for the scheme "is such that it is not outweighed by the adverse local impacts."
These impacts included "significant adverse effect on the character and appearance of the surrounding area in terms of both landscape and visual impact."
On transport impacts, the inspector found that there was "no basis to conclude that there is a problem with safe and suitable access".
"The minor difficulties which may exist on this private road by way of non-compliance with standards designed for public highways, and the need for an amount of discretion and common sense by users of the lane, are matters which can properly be taken into the planning balance, but should weigh very lightly in that balance and certainly provide no basis for substantial reasons against the scheme," the inspector’s decision notice said.
But a letter issued on behalf of the secretary of state last week said the minister had reached a different conclusion.
The note said that, given the "urgent and pressing need" for such infrastructure, the minister considered that the provision of the scheme "carries substantial weight in favour of the proposal, and the climate change benefits of the proposal also carry substantial weight".
But the letter added that the "significant adverse landscape and visual impacts, which as well as being in conflict with the development plan are also in conflict with emerging plan policies, policies of the Epping Forest Local Plan, policies of the Lee Valley Park Plan, and the National Planning Policy Framework, carry considerable weight against the proposal".
The note added that the minister "further considers that highways matters, including those on safety, carry substantial weight against the proposal".
The minister "considers that in terms of both the free flow of traffic and the safety of users, the arrangement proposed is not just ‘not ideal’ as the Inspector recognises … but unacceptable," the letter said.
Overall, "taken together, the secretary of state considers these matters justify refusal in this case," the decision letter concluded.
Last month, plans for an energy from waste facility in Swindon were approved on appeal after an inspector found that another site originally allocated for such a facility in the local plan was no longer available.
In May, London mayor Sadiq Khan criticised plans for an incinerator in Bexley, which he said were in conflict with national planning policy, and called on the government to refuse permission for the project.