Telford & Wrekin Council and the commission took action after traces of the disease were found in the grounds of an education and training campus.
"The case in Dawley is at the site within a newly planted landscape scheme where a replacement for a school is being built," said the local authority
"It has been found in a group of trees that were sourced by the main earthworks contractor Birse Civils from a nursery in Lincolnshire and planted 12 months ago.
"This was as part of the ground works contract to prepare the site ahead of the new learning community centre being built.
"The 485 newly planted ash saplings that have the disease form only a very small proportion of the overall planting scheme."
He said the council alerted the Forestry Commission after decayed leaves and sunken brown areas on the bark were spotted, prompting an on-site visit by experts.
A visual diagnostic check and tests of plant-tissue samples at Alice Holt labs and at FERA confirmed the worst.
"It is likely the council will now be served with a statutory plant health notice by Defra detailing what needs to happen next."
Councillor Shaun Davies said: "We felt it was important that people were told about this as it’s a notifiable disease and contagious within the ash tree species.
"This has been identified as a result of vigilance by council staff and we are now taking steps to clear the site of trees that are infected."
Forestry Commission’s Barnaby Wylder said: "We carried out an on site visit and photo of stem and shoot samples have been sent to our laboratory for further tests.
"The council’s prompt actions meant we could confirm the case and we are working closely on the methods needed to clear the diseased trees from the site."