Most put a slight drop from one end to the other on their RF plates, I did not, mine is installed level. My grease runs into a pipe that is in the center of the RF plate on the opposite end from the FB, down to a 1" ball valve under the pit. Whenever I clean my pit, I just hang a 3 gallon bucket under the valve and wash all the grease and buildup down the drain. In the pic, you can see the valve under the left end of the CC.
When building a RF like this do you guys make grease trap run down hill? Also what does grease run into?