Do you mean that the Data Integration project which has been removed from your Admin Center still runs in background?
Firstly, I think you have some misunderstanding with Data Integration in PowerApps. Actually, the Data Integration project you created in your PowerApps Admin Center is not stored in an specific environment.
The Data Integration project could move data from one environment to another environment. If you delete the environment (environment1) from Admin Center, the connection (you created in environment1) you added within the Connection set of your Data Integration project would be invalid.
Note: In default, if you delete a environment, the Data Integration project would not be deleted.
If you want to get further help in this issue, please consider submit an assisted support ticket through the following link: