New Orleans abides by the 25% grease trap regulation requirement.The 25% rule requires that the depth of oil and grease (floating and settled) in a trap be less than 25 percent of the total operating depth of the trap. The operating depth of a trap is determined by measuring the internal depth from the outlet water elevation to the bottom of the trap. All food service establishments in New Orleans must receive a permit from the Sewerage and Water Board of New Orleans FOG Program. Depending on whether the building or restaurant is new, and where it is located, the program lists specific grease trap permit requirements.   All grease trap manifests must be kept onsite for 3 years.