Grease Traps

There are 3 main types of grease trap: automatic, passive hydromechanical (manual), and gravity.

Automatic grease traps
Automatic systems, also known as AGRU’s (automatic grease removal units), use some of the same principals as a traditional passive trap but re-heat and skim out the FOG automatically on a programmed schedule. The skimmed FOG is then transferred into a collector bin for easy removal and recycling. The programmed schedule is based on the amount of FOG produced and means operators don’t have to measure or check grease levels. Much like passive systems they’re available in a variety of sizes to accommodate a range of requirements. While they have a higher initial investment cost, they are more efficient and have lower long-term running and servicing costs.

Passive hydromechanical (manual) grease traps
Traditional passive systems are one of the most common systems used in smaller establishments. This is due to the low initial investment cost required to purchase one and the variety of sizes available, meaning they can be easily installed under most sinks while larger units are available to accommodate bigger wastewater production requirements. Designs of manual grease traps date back to 1885 when the first U.S. patent was issued. Even today grease interceptors use the same basic operating design as the 1885 model. They’re usually constructed from plastic or stainless steel and must be cleaned manually and on a regular basis.

Gravity grease traps
Gravity systems are usually large in-ground tanks constructed from concrete, fibreglass or steel. They work in a similar way to a passive hydromechanical trap but have a much larger capacity and are better for high-flow applications. Gravity traps must be pumped out on a scheduled basis, usually by a specialist grease management service company. With public awareness of environmental issues increasing, looking into your FOG management now is potentially a wise investment and effectively future-proofs your business against future legislation which some are predicting will become more stringent in this area in years to come.