On August 30 the billing file for your September DeMotte Utility bill was created. This file did not transmit to the downstate facility that prints folds and mails your bill. 
Therefore, your bills are late. Don't worry about the late fees. 

Late fees will not be assessed until 10 days after the bills arrive. We will only be waiving the late fees that are associated with this billing. If you had previous late fees, they will remain on your account.