VHF Trunking in Northern Virginia?

I just spotted a post over on Radio Reference that someone is hearing "P25 control channels" on multiple VHF federal frequencies. No system ID, site ID, WACN or NAC information accompanied the frequencies that were posted.

Here are the frequencies that were posted:
168.8250
170.8625
170.9125
171.5375
171.6250
171.9875
172.6375
173.9000

I'd love to get some additional information from someone else that hears these so we can try to determine what they are. Many of these frequencies are being used in the federal Integrated Wireless Network (IWN) VHF trunked system in operation in Oregon and Washington. This possibly could be an expansion of the IWN sites in the DC area, but more information is needed.