That's the million dollar question. It was reported by a reliable source that CPP, Sewer and Water would go live in the March - April time frame of 2013. Sewer and Water were quickly identified, but CPP was never monitored.
If CPP did go live last April the best guess is the following encrypted talk groups TG56172, TG56173 and TG56174.
Here are two links for the messages for the March - April 2013 time frame.