Environments can be deleted from the App Settings Screen.
Click Delete next to the Environment you want to delete.
Confirm that you want to delete the Environment. Note, that this step cannot be undone.
The default Environment Development that is created for each new App in Humanitec cannot be deleted without deleting the entire App.
It might not be a good idea to delete Environments especially in the context of an audit process and audit trails. We are thus working on an Enterprise feature that will archive Environments that are not needed any longer instead of deleting them. This also allows for the recovery of deleted Environments. Reach out to us if you want to learn more about our Enterprise feature set.