These help solve the problems of fat and grease buildup - and if you operate either an "eat in" or "takeaway" restaurant then our understanding of building regulations is that you MUST have a grease trap fitted.
Removing grease also delivers real benefits:
Greatly reduced incidents of drain& pipe blockages from catering establishments.
Improvement in performance of septic tank and land drainage systems.
Prevention from contamination of small sewage treatment plants treating wastes contaminated with fat and grease and thus minimise the associated maintenance and environmental problems.