Many food service establishments don't realize cleaning filters on-site only cleans the surface. The reason is grease filters are baffle filters which have an open-side offset honeycomb shape. Because of their shape, it is near impossible to get them completely cleaned on-site.
Three methods food service establishments try to clean filters on-site (none of which are acceptable):
Besides not being able to get filters cleaned properly, when they are cleaned outside, the resulting grease-laden water bypasses the grease trap. and is washed into the stormwater drainage system.
THIS IS A SERIOUS EPA VIOLATION.
Not only can the restaurant be fined, but whatever company is cleaning the hood filters outside can also incur fines.
According to health codes that restaurants are required to follow, three-compartment sinks can ONLY be used for cleaning and sanitizing service ware. If they use their 3-compartment sinks to clean grease filters they are violating health code because they must use caustic (high pH) cleaning solutions to soak the filters.
After the filters are soaked, the grease-laden water drains into a grease trap. However, because the water is so caustic it can bypass the grease trap altogether.
When this water bypasses the grease trap sanitary sewer overflows can occur. This causes the caustic, grease-laden water to flow into public sewer systems.
Dishwasher cleaning grease filters:
Before cleaning grease filters in a dishwasher, restaurants usually soak them in a sink before placing them in the dishwasher. Once filters are dishwasher-cleaned, workers must empty the dishwasher tank of greasy water then refill it with fresh.
Because dishwashers bypass the grease trap, grease-laden water drains into the public sewer system.
