Another plumber I know called for an inspection on a 1,000 gallon grease interceptor the other day, and was written a correction notice for not having a running trap on the outlet.
I installed numerous interceptors years ago, and did'nt remember using a running trap. I can't see any mention of it in the UPC.
It was in a city in Orange County, California. Anyone ever hear of this.
In my opinion this would amount to a double trap situation.