I figured it out. About 2 years ago this frequency showed up as P25 ENC on the Scan-DC mailing list out of Montgomery Co, MD. Here's the info.
You can find the thread here:
The Scan-DC 2016 Archive by thread (Just search for Encrypted P25 on Industrial/Business Pool freqs)
The meat and potatoes:
-----Original Message-----
From: Scan-DC [mailto:scan-dc-bounces at mailman.qth.net] On Behalf Of Eric C.
Carlson
Sent: Tuesday, September 13, 2016 4:00 PM
To: Ed Tobias
Cc: Scan-DC at mailman.qth.net
Subject: Re: [Scan-DC] Encrypted P25 on Industrial/Business Pool freqs?
It's just the transmitter site on Monroe (high building for wide coverage).
If you review the FCC application files it seems he's building coverage from
Baltimore to Richmond. Also it appears the owner has a residence in the
Gaithersburg area.
-Eric
On Tue, Sep 13, 2016 at 2:05 PM, Ed Tobias <edtobias at comcast.net> wrote:
> Really interesting. There's a Cedar Grove Farm here in the Eastern
> Shore and there's one in King George County, VA. I can't see any
> connection to the 101 Monroe St. address (County Executive Office
> Building) address in Rockville.
>
> Ed
>
> On Sep 13, 2016, at 12:12 PM, Andrew Clegg
> <andrew_w_clegg at hotmail.com>
> wrote:
>
> > In an absolutely amazing coincidence, this request from Mr. Nash to
> > use
> a broader bandwidth on one of his frequencies was just released today
> by the FCC. What are the chances??
> >
> >
https://apps.fcc.gov/edocs_public/attachmatch/DA-16-1031A1.pdf
> >
> >
> >> From: andrew_w_clegg at hotmail.com
> >> To: hsimpson1 at lycos.com; scan-dc at mailman.qth.net
> >> Date: Mon, 12 Sep 2016 18:40:06 -0400
> >> Subject: Re: [Scan-DC] Encrypted P25 on Industrial/Business Pool freqs?
> >>
> >> WPMS844. Licensed to James R. Nash. 101 Monroe St, Rockville (among
> other sites). Used for farming, according to the license (a lot of
> farms in
> Rockville?)
> >>
http://wireless2.fcc.gov/UlsApp/UlsSearch/license.jsp?licKey=180023
> >> 6
> >>
> >> I don't think the FCC limits what you can do on an
> >> Industrial/Business
> Pool frequency as long as you are within your allowed technical
> constraints (power, bandwidth, emission designator, etc.).
> >>
> >> eBay is full of ads for encrypted P25 equipment for a few hundred
> dollars. A drop in the bucket compared to a John Deere tractor.
> >>
> >>> Date: Mon, 12 Sep 2016 22:21:28 +0000
> >>> From: hsimpson1 at lycos.com
> >>> To: Scan-DC at mailman.qth.net
> >>> Subject: [Scan-DC] Encrypted P25 on Industrial/Business Pool freqs?
> >>>
> >>> Been doing some long term unattended scanning and recording here
> >>> in Monkey County and saw some hits on 153.275MHz. Listening to the
> >>> recordings and they were encrypted. Is that allowable on these
> >>> type freqs? Or is our government doing something very sneaky? Cant
> >>> imaging the users of these type freqs can afford P25 encrypted
> >>> radios like the feds? Wonder what is going on?
> >>>
> >>> Jackson