See full memo at the National Postal Mail Handlers Union website 

Enclosed is a copy of the official notification that we received from the Postal Service concerning the above-cited issue. As discussed during the telecom that was held on February 26, the revised plan calls for a three tiered network in which some facilities would distribute only local and destinating mail. The Bulk Mail Centers ‘(BMCs) will be changed to Network Distribution Centers (NDCs), with three tiers of NDCs. Some of  these NDCs will perform work currently performed at nearby Processing and Distribution Centers (P&DCs) and Surface Transfer Centers (STCs).  
 
Below is the anticipated structure of the three Tier NDCs:
 
• Tier 1 NDC facilities will be re.sponsible for local and destination  standard mail, periodicals and package services. They also will perform STC containerization and dispatch operations for outgoing and incoming mail.  

• Tier 2 facilities will be responsible for all Tier 1 activities, plus  distribution of outgoing standard mail, periodicals, and package  services to the network.
 
• Tier 3 facilities will perform all the Tier 1 and 2 functions and also   will act as a consolidation point for less-than-truckload volumes  from Tier 2 sites.
 
Eventually, all BMCs are expected to become NDCs; the first three will be  the Springfield (MA), Philadelphia, and New Jersey BMCs. These three  are expected to be the “test sites” before the entire program ramps up.