Fats, Oils and Grease (FOG) Pretreatment Limits: Intent and Serious Impact of Highly Variable Implementation

The United States Environmental Protection Agency (USEPA) does not require a numerical limit for fats, oils, and grease (FOG) as part of the General Pretreatment Regulations (Code of Federal Register, Part 403). Each pretreatment program is tasked with developing a numeric limit (if needed) to prohibit any pollutant from ca using pass-through or interference in a sewer system and publicly owned treatment works (POTW). It is doubtful that there can be a ten-fold difference between numerical limits that are protective of pass-through and interference for the same-sized, same process POTWs located 200 miles apart (both in USEPA Region 5). This wide difference has serious ramifications on protection of sewer systems and the downstream POTW, and the cost of pretreatment. For a sewer system, it can mean the difference between plugged manholes and free-flowing sewers. For a dairy products plant or other industry, the difference can mean a $2 million capital investment and $400,000 annual operating cost for a negligible difference in sewer system and POTW operations. This publication will present the types of FOG limits imposed across the United States, a case study that illustrates the lack of sound reasoning that some pretreatment programs use with the unfounded cost it extracts on industry, and conclude with a pragmatic and reasonable approach taken by two sewer authorities.