I am setting up a 5th wheel RV as a permanent home. I am trying to locate a mobile pumping service to empty the black and grey water tanks on an as needed basis. I am not having any luck so far. RV will be in Glendale Az, and easily accessible. At the moment I don't have free access to my phone, too many hitchhikers here. I have to go out of the house to make any calls, which is part of the reason I am moving. If anyone has any knowledge of a service, let me know. Thank you.

Have you considered a tote?  I've been doing that for six months, and although it's a bit of a PITA, it's better than hooking up and dragging the trailer to the RV park.  Just be aware that a full tote can be VERY heavy.

I don't know of any service that would do it for small jobs like a RV tank.  Also, check your local codes for gray water use.  In my area I can use it to water the garden.

You may want to call a few of the local RV lots and see who picks up there black water.  You can also try calling some of the local septic tank pumping companies.

Can you put in a septic tank?

Call the guys that rent blue shitters. They will do it.