I don't have a 6605 near enough to test, but follow these directions for scan, disable the feature and see if it is an acceptable method for you. If it is not, you likely can't do it, and if there is an option for fax, try it to.
Limit (Restrict) Access to the Scan Feature
The Scan Lock options limit access to scanning by requiring a password to use the Scan function. Scanning can also be disabled.
To Set the Scan Lock:
If you lose the admin account after this you will need a tech to wipe the device to regain access.
I have a WorkeCentre 6605DN which I don't want to use Fax or Scan to Email features.
I can't find where to control if features is displayed or not?
Thanks in advance for any input