We've had RV hookups in both of our shops (50/30 power, water and sewer). On those, I set the pipe just a shade below grade (for spillage) and beveled the concrete down to it. Wish I had pictures here. However before that we used the clean outs on the sewer system. Ours already had a 4" fitting with female thread and a cap / plug, so screwing in the Rhino fitting worked out fine.
John and Rebecca Dickson
Emma-7 / Little John-5 / Iva-1
Full Timing Again, Rev B
2013 Ford F-350 Lariat CC LB PSD
2015 SOB TT - With OC's Awning Poles (#8)
At least in Heaven, RVs will be perfect, and I won't have to keep fixing them.